csa/montana
Den Mother
Reged: 05/14/05
Posts: 39606
Loc: montana
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Thru the kindness of a fellow CN'r who made the degree circles for me, I now have the complete setup for $12. I had the degree circles laminated on both sides (Staples-$2)
Bought an inclinometer (Home Depot $10). Had an old wall clock that I removed the hands from for pointers.
The Altitude Degree was affixed with dbl-stick tape. I siliconed the clock hand between 2 thin washers, & installed it first, against the scope, on the "spring" bolt.
Then, with the inclinometer, I adjusted the clock-hand pointer, until they agreed, all thru the scale.
On the base, again I used dbl-stick tape to affix degree circle. I drilled a small hole in the side of the lower base, using a stainless steel screw, mounted the other clock hand (hour). I then bent it to clear edge of other base & forward to point to scale. I think the set-up looks great; I don't need the inclinometer now that the pointer has been coordinated. Of course, now a front has moved in with total overcast, so I cannot try out the new "Go-To" $12 system!
Carol
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Carol
AstroTech 16" Dob (Thanks ASTRONOMICS!)
Vixen 80MF/AstroTech Voyager
Masuyama's 7.5, 15, 25W, 35mm,
Pentaxes; 5XW, 7XL, 10XW.
14mm Meade 4000 UWA
TV Panoptics; 22, 35
DreamCatcher Dobservatory, #2
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csa/montana
Den Mother
Reged: 05/14/05
Posts: 39606
Loc: montana
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Another
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Carol
AstroTech 16" Dob (Thanks ASTRONOMICS!)
Vixen 80MF/AstroTech Voyager
Masuyama's 7.5, 15, 25W, 35mm,
Pentaxes; 5XW, 7XL, 10XW.
14mm Meade 4000 UWA
TV Panoptics; 22, 35
DreamCatcher Dobservatory, #2
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csa/montana
Den Mother
Reged: 05/14/05
Posts: 39606
Loc: montana
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Last picture.
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Carol
AstroTech 16" Dob (Thanks ASTRONOMICS!)
Vixen 80MF/AstroTech Voyager
Masuyama's 7.5, 15, 25W, 35mm,
Pentaxes; 5XW, 7XL, 10XW.
14mm Meade 4000 UWA
TV Panoptics; 22, 35
DreamCatcher Dobservatory, #2
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rnabholz
scholastic sledgehammer
Reged: 07/25/04
Posts: 897
Loc: Iowa
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Carol,
Looks great, nice job.
Regarding the inclinometer versus altitude scale. The advantage of the inclinometer is that it reads the true angle of the tube regardless of the angle of the base. A base that is even just sightly off from perfect level can introduce errors into your altitude readings, and at least in my case, my eyepiece's widest field at just 1 degree leaves me little room for level induced errors.
You can certainly keep the scale, but I would take great care in leveling the base, and if it were me, I would leave the inclinometer in place during observing as a way to confirm the scale's readings.
Good Luck with the system, I'm cheering for you.
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Rod Nabholz
Home Built Astronomy Projects
Wild Bird Photography
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csa/montana
Den Mother
Reged: 05/14/05
Posts: 39606
Loc: montana
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Rod: Thanks for bringing that to my attention! I will definitely use the inclinometer. Soon I am getting the digital one you have, I have the base all ready for it.
Also thanks for all your help & encouragement, so I can have a "Go-To" scope!
Carol
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Carol
AstroTech 16" Dob (Thanks ASTRONOMICS!)
Vixen 80MF/AstroTech Voyager
Masuyama's 7.5, 15, 25W, 35mm,
Pentaxes; 5XW, 7XL, 10XW.
14mm Meade 4000 UWA
TV Panoptics; 22, 35
DreamCatcher Dobservatory, #2
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dgs©
Postmaster
Reged: 03/29/04
Posts: 15042
Loc: West Monroe, Louisiana
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Looks real snazzy... kind of like the scope should have come with them as original equipment. 
The clock hands are a good idea. 
Make sure your base is very level whenever you set it up, otherwise your Alt scale could be off a little.
I assume you are using a compass to align your Azimuth scale with true North? If so, keep in mind that magnetic North and True (celestial) North don't always agree. Furthermore, magnetic North wanders around, noticeably over the course of a few years.
Here is a good NOAA site for determining what your magnetic declination is.
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- david
8"Ø Newtonian on SVP, Moonlite CR2, Telrad
PST Oberwerk Ultra 15x70 Orion Ultraview 10×50
Hand-me-down Sears Refractor (Discoverer) 60mm×900mm
"What we have done for ourselves alone dies with us; what we have done for others and the world, remains and is immortal." --Albert Pike
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SkyArcher
Post Laureate
Reged: 04/12/06
Posts: 3416
Loc: 9545' in Colorado
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Carol, That looks great! You did a nice job!
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Sir Skyler Archibald.....
An 8" Deep Space Hunter
4.5 w/ GOTO
4.5 newt w/ home built Dob mount
Omphaloskepsis - I didn't realize that there is a word for what I do while waiting for web pages to download 
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csa/montana
Den Mother
Reged: 05/14/05
Posts: 39606
Loc: montana
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Thanks to "Honey's" master!
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Carol
AstroTech 16" Dob (Thanks ASTRONOMICS!)
Vixen 80MF/AstroTech Voyager
Masuyama's 7.5, 15, 25W, 35mm,
Pentaxes; 5XW, 7XL, 10XW.
14mm Meade 4000 UWA
TV Panoptics; 22, 35
DreamCatcher Dobservatory, #2
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csa/montana
Den Mother
Reged: 05/14/05
Posts: 39606
Loc: montana
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Thanks David: It was suggested to me that I point the scope to Polaris, then rotate base to "0". I will try both this, & a compass if & when the "curse" lifts the clouds,  to see which is easier for me & most accurate.
Carol
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Carol
AstroTech 16" Dob (Thanks ASTRONOMICS!)
Vixen 80MF/AstroTech Voyager
Masuyama's 7.5, 15, 25W, 35mm,
Pentaxes; 5XW, 7XL, 10XW.
14mm Meade 4000 UWA
TV Panoptics; 22, 35
DreamCatcher Dobservatory, #2
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Hillbilly_Gazer
Court Jester
Reged: 11/17/04
Posts: 1856
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Quote:
Looks real snazzy... kind of like the scope should have come with them as original equipment.
That was my exact thought. Nice work!
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Orion XT-8
Orion Scenix 10x50 WA Binoculars
And not a whole lot else!
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typhus
professor emeritus
Reged: 11/06/04
Posts: 667
Loc: Tucson, AZ
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Those are nice Carol. Using the degree circles sounds like it would be more fun observe than DSC. Let us know how they work out for you.
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Shane
Orion XT10i
10x50 Binoculars
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Curt B
super member
Reged: 08/02/05
Posts: 191
Loc: Regina, Canada
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Good luck Carol. When I did the same thing to my dob, it opened up a whole new world for me! What program are you using to find the objects?? I use Planetarium on my Palm. I also play around with PleiadAtlas. It is an easier interface than Planetarium, but I don't think it is quite as accurate, but still gets you pretty close.
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TV 85
GSO 30 & 26mm 2" eyepieces
24mm Pan,13mm Ethos,6-3 Nagler Zoom
Celestron Power Tank 17
Astro-Tech Voyager Mount
Celestron SLT Mount
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csa/montana
Den Mother
Reged: 05/14/05
Posts: 39606
Loc: montana
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I haven't decided on a program yet; do you have a website for PleiadAtlas? The easier, the better for me! Also, did you use a compass on the base, or put scope on Polaris, & turn the base to "0"?
Thanks!
Carol
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Carol
AstroTech 16" Dob (Thanks ASTRONOMICS!)
Vixen 80MF/AstroTech Voyager
Masuyama's 7.5, 15, 25W, 35mm,
Pentaxes; 5XW, 7XL, 10XW.
14mm Meade 4000 UWA
TV Panoptics; 22, 35
DreamCatcher Dobservatory, #2
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rnabholz
scholastic sledgehammer
Reged: 07/25/04
Posts: 897
Loc: Iowa
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Carol,
When you get tired of hearing from me, just say so.
With regards to aligning the base, I have a cheap $4 compass permanently installed in the base of my scope that helps me get somewhat close to north when I set up the scope.
Then, to "calibrate" I use any known object, many times a star or planet visible well before Polaris is visible. Center that object in the field and adjust the dial to match. My approach was to build it about 20 degrees of adjustability on the dial. That approach allows you to adjust without disturbing the position of the scope, nice if you have spent any time carefully leveling the base.
Remember that each time you move the scope base to adjust your calibration, you will likely move the scope enough to loose the calibration object and will have to reacquire the target and check the reading and repeat. Might be a bit tedious.
An approach I have seen in a set up like yours with a non-adustable scale is to make the pointer movable. One way to do that is a pointer mounted on a magnet that attaches to a steel plate along the edge of the scale. Once centered on an object, You simply move the pointer to match the appropriate reading, again leaving your scope undisturbed, still level and centered on your calibration target.
Hope this helps.
Rod
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Rod Nabholz
Home Built Astronomy Projects
Wild Bird Photography
Edited by rnabholz (05/03/06 11:43 AM)
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csa/montana
Den Mother
Reged: 05/14/05
Posts: 39606
Loc: montana
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Rod: I won't live long enough to get tired of you trying to help me get set up! Can you explain a little more about the steel plate along the edge of the scale? This idea sounds great, as I know it will be very difficut for me to move the base (full weight of scope!).
Carol
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Carol
AstroTech 16" Dob (Thanks ASTRONOMICS!)
Vixen 80MF/AstroTech Voyager
Masuyama's 7.5, 15, 25W, 35mm,
Pentaxes; 5XW, 7XL, 10XW.
14mm Meade 4000 UWA
TV Panoptics; 22, 35
DreamCatcher Dobservatory, #2
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rnabholz
scholastic sledgehammer
Reged: 07/25/04
Posts: 897
Loc: Iowa
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Carol,
Imagine a piece of thin steel - the steel strapping used on lumber or pallets would work great. You simply attach, say, 6 inches of that to the edge of your groundboard with a couple of screws.
Then attach your pointer to a small magnet, and stick it to the center of the steel strip.
When you need to tweak your calibration you simply slide the pointer along this strip of steel strapping until it matches the computer's azimuth setting and you are good to go.
Let me know if that is clear as mud and I will try again. 
Rod
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Rod Nabholz
Home Built Astronomy Projects
Wild Bird Photography
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csa/montana
Den Mother
Reged: 05/14/05
Posts: 39606
Loc: montana
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Rod: something else that may work is magnetic stripping. I called the local hdwre store, & they have it (used for holding screwdrivers, etc.) It's flexible, so I thought I'd screw it around the edge of the base, then mount my clock-hand pointer on a small magnet. What do you think of this?
Carol
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Carol
AstroTech 16" Dob (Thanks ASTRONOMICS!)
Vixen 80MF/AstroTech Voyager
Masuyama's 7.5, 15, 25W, 35mm,
Pentaxes; 5XW, 7XL, 10XW.
14mm Meade 4000 UWA
TV Panoptics; 22, 35
DreamCatcher Dobservatory, #2
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rnabholz
scholastic sledgehammer
Reged: 07/25/04
Posts: 897
Loc: Iowa
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My only thought on that might be that you could have a situation where the polarities of the strip and small magnet would clash and not let you place the pointer precisely where you would like. Take the small magnet to the store and try it out.
If you live anywhere near a lumberyard or home improvement center, they would likely let you take all the steel strapping you wanted for nothing. Most of the time the yard is littered with the stuff and some poor soul (like me on my summer job as a kid) has to schlep around and pick it up and toss it.
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Rod Nabholz
Home Built Astronomy Projects
Wild Bird Photography
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csa/montana
Den Mother
Reged: 05/14/05
Posts: 39606
Loc: montana
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After thinking about it, I agree, the strapping would be better (and the price? PRICELESS!) Besides, the cost will still be $12, + 1 small magnet, & a few s.steel screws! How much better can it get? Off to the lumber yard, I go!
Now, all that will be left? Overcast, go away! 
Carol
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Carol
AstroTech 16" Dob (Thanks ASTRONOMICS!)
Vixen 80MF/AstroTech Voyager
Masuyama's 7.5, 15, 25W, 35mm,
Pentaxes; 5XW, 7XL, 10XW.
14mm Meade 4000 UWA
TV Panoptics; 22, 35
DreamCatcher Dobservatory, #2
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SkyArcher
Post Laureate
Reged: 04/12/06
Posts: 3416
Loc: 9545' in Colorado
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Carol, I use Pocket Stars on my PDA (Dell Axim) and Cartes du Ciel on my laptop to give me the coordinates that I need to find stuff. CdC is free but Pocket Stars is $19. CdC shows the comets and lets you update the database. Pocket Stars does not show comets but if I look up the comets on CdC then I can pick it out from the Pocket Stars.
The PDA is definately easier to use out in the field than the laptop.
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Sir Skyler Archibald.....
An 8" Deep Space Hunter
4.5 w/ GOTO
4.5 newt w/ home built Dob mount
Omphaloskepsis - I didn't realize that there is a word for what I do while waiting for web pages to download
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Fireball
sage
Reged: 03/24/06
Posts: 347
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Quote:
Carol,
Imagine a piece of thin steel - the steel strapping used on lumber or pallets would work great. You simply attach, say, 6 inches of that to the edge of your groundboard with a couple of screws.
Then attach your pointer to a small magnet, and stick it to the center of the steel strip.
When you need to tweak your calibration you simply slide the pointer along this strip of steel strapping until it matches the computer's azimuth setting and you are good to go.
Let me know if that is clear as mud and I will try again.
Rod
Sounds interesting and simple.
Is it possible to show a picture of this set-up ?
That would make everything very clear.
Thanks !
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20x90 Bino
12" Lightbridge
Meade UWAs, TV Ethoi, Pentax XW, Hyperion, AT Titan.
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csa/montana
Den Mother
Reged: 05/14/05
Posts: 39606
Loc: montana
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Fireball: Go to top of this post, my first picture.
On the outer side edge of the lower circular base, the metal strip will be affixed there, completely around the base; then where the pointer is,(screwed in), I now will have the pointer glued to a small magnet that I can now move anywhere on the degree circle, to get set up.
Carol
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Carol
AstroTech 16" Dob (Thanks ASTRONOMICS!)
Vixen 80MF/AstroTech Voyager
Masuyama's 7.5, 15, 25W, 35mm,
Pentaxes; 5XW, 7XL, 10XW.
14mm Meade 4000 UWA
TV Panoptics; 22, 35
DreamCatcher Dobservatory, #2
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csa/montana
Den Mother
Reged: 05/14/05
Posts: 39606
Loc: montana
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Ron: Just downloaded trial PC version, & am ordering PC & PDA version. This is a great program, just what I was looking for. Now, I'm going to try to find a good price on the Axim. Again, thanks for all your help, couldn't have done it without your kindness & expertise!
Carol
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Carol
AstroTech 16" Dob (Thanks ASTRONOMICS!)
Vixen 80MF/AstroTech Voyager
Masuyama's 7.5, 15, 25W, 35mm,
Pentaxes; 5XW, 7XL, 10XW.
14mm Meade 4000 UWA
TV Panoptics; 22, 35
DreamCatcher Dobservatory, #2
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Curt B
super member
Reged: 08/02/05
Posts: 191
Loc: Regina, Canada
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Here is the link for Pleiadatlas
http://astro.isi.edu/pleiadatlas/
and Planetarium
http://www.aho.ch/pilotplanets/
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TV 85
GSO 30 & 26mm 2" eyepieces
24mm Pan,13mm Ethos,6-3 Nagler Zoom
Celestron Power Tank 17
Astro-Tech Voyager Mount
Celestron SLT Mount
Edited by Curt B (05/03/06 06:53 PM)
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rnabholz
scholastic sledgehammer
Reged: 07/25/04
Posts: 897
Loc: Iowa
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Carol,
Of course the call is yours to make, but if it were me, I wouldn't bother to make the strip go all the way around.
6-12" of strapping would give you around 30 to 45 degrees of adjustment, plenty for even a casual initial polar alignment.
Just another two cents - making my total to date $3.08.............Sorry.
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Rod Nabholz
Home Built Astronomy Projects
Wild Bird Photography
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csa/montana
Den Mother
Reged: 05/14/05
Posts: 39606
Loc: montana
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Rod: Again, thanks! Didn't realize this. It will save me a lot of work. Can tell I'm an amateur at this, huh? I've got the "0" degree mark on the left side, so a short strip running each way of this would be good?
Carol (p.s. you have a credit of many thousands of $, so I can pick your brain a lot, at 2cents a question, I'm gonna keep you verrrry busy!)
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Carol
AstroTech 16" Dob (Thanks ASTRONOMICS!)
Vixen 80MF/AstroTech Voyager
Masuyama's 7.5, 15, 25W, 35mm,
Pentaxes; 5XW, 7XL, 10XW.
14mm Meade 4000 UWA
TV Panoptics; 22, 35
DreamCatcher Dobservatory, #2
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rnabholz
scholastic sledgehammer
Reged: 07/25/04
Posts: 897
Loc: Iowa
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Exactly, just a few inches on both sides of zero will do the trick.
Glad to help.
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Rod Nabholz
Home Built Astronomy Projects
Wild Bird Photography
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AtLarge
super member
Reged: 08/22/05
Posts: 150
Loc: 868 Ft. Above Sea Level
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Quote:
Exactly, just a few inches on both sides of zero will do the trick.
Glad to help.
This is very informative but let me make sure I have this straight.
The pointer is on the bottom base.
The pointer is aligned with Polaris and the base leveled.
The steel band with magnet on pointer allow for adjustments so you can tweak that alignment by moving the pointer after you test on some known objects. (without having to keep moving the entire bottom base)
If the markings are on the top board and are stationary with the OTA where do you set the gradients to begin with? The zero / zero goes directly below the center of the OTA at the front of the scope? That way you always begin with the scope pointed at the Polar North.
You then match the Azm:159 and Alt:+38 as per your favorite program (my settings at the moment for Jupiter) and your on target or at least in the neighborhood.
Am I keeping up here or did I miss something? 
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Meade Lightbridge 12'' Deluxe with Orion COL.
Meade Series 4000 Plossl 7 Eyepieces & 5 Filters
Meade 114NT/500 Dwarf Dobsonian
Meade DS-114ATE
Meade 60AZ-T
Meade 227
Burgess BV125
Konus 2110 20x80mm Giant Astronomy Binoculars
Carson 20-100x70mm
Bushnell 16x50mm
 Oh, no. Not again!
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rnabholz
scholastic sledgehammer
Reged: 07/25/04
Posts: 897
Loc: Iowa
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You have it.
In Carol's pictures you can see that she set zero at 90 degrees from the tube, but it really doesn't matter that the scale match the actual azimuth direction, only that the scale and pointer indicate properly. Her approach makes it convenient to see when at the eyepiece when the scope is pointed north.
Using the approach where the scale is attached to the rocker means that you will have to leave the eyepiece position at times to line up the pointer. The approach I used is to put the scale on the groundboard and build some adjustability into the scale rather than the pointer. That allows the pointer, attached to the rocker, to be visible from the eyepiece at all times, a little handier set up, but a little more complicated build.
Let me know if you have other questions.
Clear Skies
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Rod Nabholz
Home Built Astronomy Projects
Wild Bird Photography
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csa/montana
Den Mother
Reged: 05/14/05
Posts: 39606
Loc: montana
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See my new post here "my $12 Go-To" test drive
Carol
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Carol
AstroTech 16" Dob (Thanks ASTRONOMICS!)
Vixen 80MF/AstroTech Voyager
Masuyama's 7.5, 15, 25W, 35mm,
Pentaxes; 5XW, 7XL, 10XW.
14mm Meade 4000 UWA
TV Panoptics; 22, 35
DreamCatcher Dobservatory, #2
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SkyArcher
Post Laureate
Reged: 04/12/06
Posts: 3416
Loc: 9545' in Colorado
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In case any wants it, I've attached the pdf of the file I used to make the degree circle. You can take the pdf to your local "Kinkos" copy center and have them print it out on 24x36 paper. Also while you're there, have them laminate the degree circles.
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Sir Skyler Archibald.....
An 8" Deep Space Hunter
4.5 w/ GOTO
4.5 newt w/ home built Dob mount
Omphaloskepsis - I didn't realize that there is a word for what I do while waiting for web pages to download
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Relativist
Post Laureate
Reged: 10/11/03
Posts: 3081
Loc: OC, CA, USA
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Just out of curiosity, how good is that home depot inclinometer? Could we maybe make our own that was a bit better?
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.......Curtis
20mm T2 Nagler, 10mm SW 82degrees, 5-8 SW Zoom:
All of the above replaced with WO Binoviewers!!!
Siebert OCA 1.25x-3.5x
10" OPT Starhunter (flocked & upgraded focuser)
10x50 & 15x70 Celestron Bino's
2" 2x GSO Barlow
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csa/montana
Den Mother
Reged: 05/14/05
Posts: 39606
Loc: montana
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It's about 4-3/4" high (circular), with magnetic base. As Rod Nabholtz said, using the inclinometer, it's independent of the base, so no leveling is required.The scale is quite small & a little difficult to read at night, but works. During my viewing session, My Altitude degree scale matched the inclinometer with each change. The ideal one is what Rod has now; MD SmartTool digital level. It runs $100 though. I'm quite happy with my setup & accuracy.
Carol
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Carol
AstroTech 16" Dob (Thanks ASTRONOMICS!)
Vixen 80MF/AstroTech Voyager
Masuyama's 7.5, 15, 25W, 35mm,
Pentaxes; 5XW, 7XL, 10XW.
14mm Meade 4000 UWA
TV Panoptics; 22, 35
DreamCatcher Dobservatory, #2
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Relativist
Post Laureate
Reged: 10/11/03
Posts: 3081
Loc: OC, CA, USA
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Ok, so let me ask this, could you use the inclinometer to "calibrate" the Altitude scale, bypassing the need to level the base? The idea would be to move the arrow as is done with the Azimuth scale.
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.......Curtis
20mm T2 Nagler, 10mm SW 82degrees, 5-8 SW Zoom:
All of the above replaced with WO Binoviewers!!!
Siebert OCA 1.25x-3.5x
10" OPT Starhunter (flocked & upgraded focuser)
10x50 & 15x70 Celestron Bino's
2" 2x GSO Barlow
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THESKY
scholastic sledgehammer
Reged: 02/16/06
Posts: 927
Loc: SOCAL
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Boy this is such a good thread . . . thank you for all . . . especially Carol who initiate this thread. Also to Rob and SkyArcher who make the Alt/Az degree circle work.
I also plan to do the same since it is doable.
My question will be when you have a tracking platform how do you calibrate the level. When you just start tracking you will have the platform swing to the east side and then it will end as it swing all the way to the west for 60 - 80 minutes.
I guess one solution will be searching for the object while the rocker base is level and after the object is in the FOV - turn on the tracking device.
Ridwan
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10x42L IS
12" DSH
3.5, 5, 7,
10, 14, 20,
30, 40
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rnabholz
scholastic sledgehammer
Reged: 07/25/04
Posts: 897
Loc: Iowa
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Curtis,
Using a scale without a level base is problematic because while you can always set the scale to match an inclinometer determined setting, when you turn the rocker on the base, the scale reading will be off immediately and will not be exactly accurate until you return it to the same azimuth you set it at.
Now, depending in the degree of deviation from level, this error could be small, but it could also be very large and make finding things in a one degree or so field of view very difficult.
The inclinometer takes away the possibility of this error, and so makes it the choice for me. The analog inclinometer mentioned in this thread is about $10, a cheap efficient solution.
Of course leveling the scope is another option, and actually, I do both to make things as accurate as possible.
--------------------
Rod Nabholz
Home Built Astronomy Projects
Wild Bird Photography
Edited by rnabholz (05/09/06 10:39 AM)
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rnabholz
scholastic sledgehammer
Reged: 07/25/04
Posts: 897
Loc: Iowa
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Ridwan,
I have given the tracking platform issue some thought, as I am conisidering building one for my scope.
I think the only approach that will work is stopping and returning the platform to level during the object acquisition process and then turning the motors on.
You would sacrifice 50% of your tracking period, but depending on the platform you would likely have 20 to 30 minutes of travel left. That would generally be enough for my purposes.
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Rod Nabholz
Home Built Astronomy Projects
Wild Bird Photography
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THESKY
scholastic sledgehammer
Reged: 02/16/06
Posts: 927
Loc: SOCAL
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Rod,
That is what I thought . . . having the dob level - align to the object (Alt/Az) - then turn on the tracking. Thank you for that confirmation.
Or another idea would be . . . calculating the difference between a leveled platform and a maximum swing platform. Then we can use this different to a Alt/Az value from the pocket star.
What do you think about that one?
--------------------
10x42L IS
12" DSH
3.5, 5, 7,
10, 14, 20,
30, 40
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rnabholz
scholastic sledgehammer
Reged: 07/25/04
Posts: 897
Loc: Iowa
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Quote:
Or another idea would be . . . calculating the difference between a leveled platform and a maximum swing platform. Then we can use this different to a Alt/Az value from the pocket star.
What do you think about that one?
Well, here is what I have come up with as I have pondered using a platform.
Remember that if you adopt my strongly preferred approach for altitude - an inclinometer, not a scale, the tube reading is always read independent of the base. So even on a platform the altitude reading will be accurate.
It is the azimuth that is vexing. Visualizing the base and the azimuth scale and the different possible orientations of that scale to the tilt of the platform, it seems to me that you would have an infinitely variable factor to consider.
For example, consider the scope pointing precisely perpendicular to the axis of platform rotation or pointing precisely parallel to the axis of rotation. In these cases, your azimuth is likely to be pretty accurate.
Now consider the scope pointing in between those points. It seems to me that depending on the degree of the platform tilt, you would compromise the accuracy of the scale because you have in effect compressed the spacing of the degree marks by tilting the scale.
If my visualizations are correct (and PLEASE, anybody who sees this differently please let me know your thoughts) you would have a very difficult time quantifying the deviation and therefore could probably not easily adjust for it.
Edited by rnabholz (05/09/06 12:28 PM)
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SkyArcher
Post Laureate
Reged: 04/12/06
Posts: 3416
Loc: 9545' in Colorado
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Rob, I'm just having a little brain fart here, but I'm thinking that if you're using a tracking platform, wouldn't it be better to use the other set of coordinates (RA-DEC) and set up a different set of degree circles. I confess that I don't know what Ra-Dec coordinates are other than they are used on EQ mounts.
--------------------
Sir Skyler Archibald.....
An 8" Deep Space Hunter
4.5 w/ GOTO
4.5 newt w/ home built Dob mount
Omphaloskepsis - I didn't realize that there is a word for what I do while waiting for web pages to download
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rnabholz
scholastic sledgehammer
Reged: 07/25/04
Posts: 897
Loc: Iowa
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Quote:
Rob, I'm just having a little brain fart here, but I'm thinking that if you're using a tracking platform, wouldn't it be better to use the other set of coordinates (RA-DEC) and set up a different set of degree circles. I confess that I don't know what Ra-Dec coordinates are other than they are used on EQ mounts.
I suppose that you could develop a way to put RA-Dec circles on a platform mounted dob, I have never seen that done, so I can't say that I understand the possible pitfalls.
I guess my way of thinking about this approach is that there may be times when I would use the scope without the platform so the alt/az circles are useful in both settings.
Setting the platform back to level to use the circles can be a quick and simple process on the non-tangent drive platforms, so it seems like a simple solution.
Of course, one could simply get a Equatorial Mount and skin the cat that way if tracking was a requirement.
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Rod Nabholz
Home Built Astronomy Projects
Wild Bird Photography
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THESKY
scholastic sledgehammer
Reged: 02/16/06
Posts: 927
Loc: SOCAL
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I just did some calculation on delta between leveled and full swing platform. It does not work. Because the delta is not a consistant number. The object closer to Polaris for example will have a different delta from an object away from Polaris.
In regard to your inclinometer, I assume when you mount the inclinometer on the tube - it has to be vertical in order to get an accurate reading of the altitude. But . . . when you have a platform swings all the way . . . the inclinometer is not necessarily vertical anymore.
So even using an adjustable mounting, there should be a way to compensate vertical axis.
The RA and Dec method is even more complicated because dobsonian has only two UN-adjustable plane (vertical and horizontal) With RA and Dec, you need to have a 3rd axis in order to make the 2 planes coincide with the true North (Polaris) . . . like the the equatorial mount. . . . Unless I am wrong . . .
Have fun tinkering . . . I am going to sleep on it again . . .
Ridwan
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10x42L IS
12" DSH
3.5, 5, 7,
10, 14, 20,
30, 40
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rnabholz
scholastic sledgehammer
Reged: 07/25/04
Posts: 897
Loc: Iowa
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Quote:
I just did some calculation on delta between leveled and full swing platform. It does not work. Because the delta is not a consistant number. The object closer to Polaris for example will have a different delta from an object away from Polaris.
I am curious, as I suggested in the earlier post, I suspect that as you move toward one of the multiples of 90 degrees - 0 - 90 - 180 -270- 360 you reduce the error. Stated another way, at 0 degrees no error - increasing error to 45 degrees - then decreasing error to 90 where it is minimal, or even eliminated. Continuing the same way every 90 degrees all the way around.
Does this make sense to anyone but me?
Quote:
In regard to your inclinometer, I assume when you mount the inclinometer on the tube - it has to be vertical in order to get an accurate reading of the altitude. But . . . when you have a platform swings all the way . . . the inclinometer is not necessarily vertical anymore.
So even using an adjustable mounting, there should be a way to compensate vertical axis.
The RA and Dec method is even more complicated because dobsonian has only two UN-adjustable plane (vertical and horizontal) With RA and Dec, you need to have a 3rd axis in order to make the 2 planes coincide with the true North (Polaris) . . . like the the equatorial mount. . . . Unless I am wrong . . .
Have fun tinkering . . . I am going to sleep on it again . . .
Ridwan
Regarding the inclinometer, the analog unit would be susceptible to mechanical error- the indicator would rub on the housing. I am not sure about my electronic unit, I haven't tried it in anything but a normal attitude.
Have to give that a try.
Interesting to think about. Thanks
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Rod Nabholz
Home Built Astronomy Projects
Wild Bird Photography
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THESKY
scholastic sledgehammer
Reged: 02/16/06
Posts: 927
Loc: SOCAL
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Hey Rod,
Just got back from a few hours of observing. The platform and the inclinometer worked very well. I bought the digital one (smarttool - Craftsman) and mount
using a magnetic strip - the program I use Equinox (for Macs) and the platform I use Tom Osypowski's.
I swing the platform all the way - then look for Jupiter - both the program and inclinometer agrees in the altitude with about 0.25 degrees of error.
Then I turned on the tracking and let it track for about 45 minutes or so and again the inclinometer agrees with the program. It is really cool!
I have not installed the azimuth yet since Kinko messed up the enlargement.
Skyarcher make a 19" degrees circle but my DSH base is 25" (I have a 12" DSH) So I have to calculate the percentage of enlargement. Anyway it is almost done.
Thanks again for sharing the idea . . . now I got a goto system fairly affordable. The smart tool $80 was well worth it. Total was still under $100.
Ridwan
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10x42L IS
12" DSH
3.5, 5, 7,
10, 14, 20,
30, 40
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rnabholz
scholastic sledgehammer
Reged: 07/25/04
Posts: 897
Loc: Iowa
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Hi Ridwan,
You got out and tested the SmartTool before I had a chance to. I am pleased to hear that it works properly even if tilted slightly off axis. I had suspected it would, but nothing beats a true field test.
$80 is a great buy on the level. I knew Sears carried them, but at the time I bought mine, their price was higher by $20. My guess is given a year, this tool will be in the $50 range.
The device is quite accurate, my experience matches yours, the error is very small, a quarter of a degree makes this part of the system well within acceptable tolerance. Add that to the resolution possible with a 20" azimuth dial and you have a system that works very well as you and those who have implemented it have discovered.
The whole thing can be done for about $100 to $125. Moving to additional scopes your cost is just that of the azimuth scale and a mount for the level ~$20 or so.
One other advantage this system has over traditional DSC is its ability to work with a scope that is not perfectly orthagonal. Any deviation from perfect orthagonality of the axis on a dob will cause a DSC to not perform up to its capabilities. This system is immune to that issue.
I am very interested to hear of your results with the total system on the platform. Please be sure and post your observations when you have the azimuth dial in place.
Thanks
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Rod Nabholz
Home Built Astronomy Projects
Wild Bird Photography
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csa/montana
Den Mother
Reged: 05/14/05
Posts: 39606
Loc: montana
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Thanks for letting us know Sears sells the "SmartTool".
My local hardware store & lumber had only the 24"level w/smart tool for $139! Couldn't order just the module; Sears, it is!
Carol
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Carol
AstroTech 16" Dob (Thanks ASTRONOMICS!)
Vixen 80MF/AstroTech Voyager
Masuyama's 7.5, 15, 25W, 35mm,
Pentaxes; 5XW, 7XL, 10XW.
14mm Meade 4000 UWA
TV Panoptics; 22, 35
DreamCatcher Dobservatory, #2
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THESKY
scholastic sledgehammer
Reged: 02/16/06
Posts: 927
Loc: SOCAL
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Oh yeah . . . forgot to include the price of the program (Equinox). It is $50.
I haven't bought it yet though - still using trial version. I like to try the planetarium with Palm pilot before purchasing. I know that the Palm is much smaller and easier to carry/store. But I like the big screen on my laptop -12". I can set to see the whole sky (180 degrees) or part of it (up to 5 degrees). I can also see both coordinates in RA/DEC and Alt/Az. One other advantage of Equinox over Planetarium is that I am able to use the program for tracking What it is invloved - I don't know yet. Oh yeah . . . one more thing MACs hardly crash . . . he he he . . .
So all in all the price for this HYBRID degrees setting is around $150.
Still way cheaper than a DSC which will cost me around $700 (the unit and the mounting kit)
(I use hybrid since the smartTool is digital for the Alt. But for the Az is analog)
Happy Tinkering people.
Ridwan
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10x42L IS
12" DSH
3.5, 5, 7,
10, 14, 20,
30, 40
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kestrel0222
Carpal Tunnel
Reged: 05/21/06
Posts: 2338
Loc: Milford, Michigan
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SkyArcher, what program did you use to create the great looking degree circle with? I need one for my scope, but my base is slightly larger than the 19" one you have in your PDF file. My base is 22" outside diameter and the width of the circle needs to be 3/4". Any thoughts on how I can make one of these?
Thanks,
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Tom
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SkyArcher
Post Laureate
Reged: 04/12/06
Posts: 3416
Loc: 9545' in Colorado
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Hi Tom, I used AutoCad.
An easy way for you to do this is take the file to Kinkos
and have them enlarge the file by 115%. That will give you a 22" circle. Then while you're there, have them laminate it on both sides.
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Sir Skyler Archibald.....
An 8" Deep Space Hunter
4.5 w/ GOTO
4.5 newt w/ home built Dob mount
Omphaloskepsis - I didn't realize that there is a word for what I do while waiting for web pages to download
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kestrel0222
Carpal Tunnel
Reged: 05/21/06
Posts: 2338
Loc: Milford, Michigan
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Thanks, I guess since I work on a high end graphics sytem (CATIA V5) that I will just import that PDF file, plot it out at 115% scale (as you suggested)  and I'll be all set!! I will have it laminated.
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Tom
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Clif
member
Reged: 07/19/06
Posts: 55
Loc: Perrineville New Jersey
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Similar approach: I discovered that the plotting accuracy of today's ink jet printers is quite impressive (on a Mac at least, don't know how well it works on a windows system) and the drafting ability of many drawing programs (MacDraw, ClarisDraw, Canvas, probably the CAD packages too) is just as good. Combining these, I have found that one can make setting circles which are very servicable by just drawing them on the computer, printing them out on the ink jet printer and laminating them to plywood circles using liquid epoxy. They are at least as accurate as 0.1 degrees which is about as good as you can read a circle anyway. I have even made verniers for the circles this way. If anyone wants details, I can expand on the technique. Attached is a picture of a 24" RA circle I made this way. The small divisions are one minute of RA in size. The circle is for a big reverse fork mount I am working on.
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Either an astronomer with a lab in the basement or a chemist with an observatory in the back yard...
12.5"f/6 Newtonian. Planetary webcam photography. Double star measurement.
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Astraforce Paul
Carpal Tunnel
Reged: 04/05/05
Posts: 1875
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Clif, yes, please describe more about what you did. Do any of those programs automatically put the circle number in? I presume so. Is there a freebie program or demo program for the Mac that one could test this with? Anyone besides Cliff who knows please chime in, too!
I'm interested in rolling my own template (I like your BIG numbers--easier to read) with my own degree markings (e.g., longer 5 degree line, no outer checkerboard, etc.).
How did you handle the overlapping? I've found that my inkjet does NOT print to the border so that there is a white, unprinted border. It's a bit tricky overlapping the sheets.
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Clif
member
Reged: 07/19/06
Posts: 55
Loc: Perrineville New Jersey
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No, everything is put in by hand, but it was not very difficult. The tic marks are really lines going all the way across that were put into final position by copying, rotating, grouping, copying, rotating, etc. The numbers had to be rotated also and individually placed. Masking white opaque circles with black borders were plotted on top of the maze of crossed lines to leave the tic marks sprouting from the edge of the circle. I used MacDraw Pro which is just the grown up version of MacDraw that used to be given away free with all Macs. ClarisDraw, Kalaidadraw and Canvas would probably have enough tools to let you do it, PC or Mac.
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Either an astronomer with a lab in the basement or a chemist with an observatory in the back yard...
12.5"f/6 Newtonian. Planetary webcam photography. Double star measurement.
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chmee
super member
Reged: 05/11/05
Posts: 158
Loc: Takoma Park, MD
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How about using the smarttool w/ well-designed mount (a la Rod's) for altitude ($80 at sears), and a digital compass for azimuth (see also at sears, for example, $20), total price $100 plus tax.
I don't know how accurate the compass is. It only reads out to the nearest degree. However, Rod points out that by calibrating the smarttool mount onsite, one can get the altitude spot-on every time. This reduces the searching to just azimuth, and a search on only one axis is trivial.
The other problem w/ the compass is the magnetic declination, as pointed out above. However, one can look this up ahead of time (it appears to be 10 degrees 45' west for my location near DC), and compensate onsite.
Does this sound reasonable to anyone? Anyone have experience w/ digital compasses and have an idea how precise they are?
Cheers,
pete
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Curt B
super member
Reged: 08/02/05
Posts: 191
Loc: Regina, Canada
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I use Planetarium on my Palm to look for my objects. There is an option for magnetic azimuth on it, so it should solve the problem of knowing what true north is. My only concern is will the metal OTA interfere with the compass?
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TV 85
GSO 30 & 26mm 2" eyepieces
24mm Pan,13mm Ethos,6-3 Nagler Zoom
Celestron Power Tank 17
Astro-Tech Voyager Mount
Celestron SLT Mount
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chmee
super member
Reged: 05/11/05
Posts: 158
Loc: Takoma Park, MD
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Quote:
I use Planetarium on my Palm to look for my objects. There is an option for magnetic azimuth on it, so it should solve the problem of knowing what true north is. My only concern is will the metal OTA interfere with the compass?
Good question. I ordered the cheap wayfinder from amazon ($17) and will try it this weekend. I don't have a big tube, but do have four long aluminum poles (2" diameter), so it would probably be similar. However, it's supposed to work inside a car or truck, w/ an indicator when bothered by interference from metal, so we'll see.
pete
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16" dob
ED80sf
15x50 IS binocs
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Curt B
super member
Reged: 08/02/05
Posts: 191
Loc: Regina, Canada
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Looking forward to hearing about your results chmee....please keep us posted!
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TV 85
GSO 30 & 26mm 2" eyepieces
24mm Pan,13mm Ethos,6-3 Nagler Zoom
Celestron Power Tank 17
Astro-Tech Voyager Mount
Celestron SLT Mount
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chmee
super member
Reged: 05/11/05
Posts: 158
Loc: Takoma Park, MD
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Quote:
Good question. I ordered the cheap wayfinder from amazon ($17) and will try it this weekend. I don't have a big tube, but do have four long aluminum poles (2" diameter), so it would probably be similar. However, it's supposed to work inside a car or truck, w/ an indicator when bothered by interference from metal, so we'll see.
pete
No go, it only registers in increments of 5 degrees, and even that might be overstating its accuracy. My sense is that this is representative of other cheap digital compasses as well.
Oh well, at least it works quite well for its intended purpose, i.e. in the car.
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16" dob
ED80sf
15x50 IS binocs
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Curt B
super member
Reged: 08/02/05
Posts: 191
Loc: Regina, Canada
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Sorry to hear that....was looking forward to hearing about your results...
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TV 85
GSO 30 & 26mm 2" eyepieces
24mm Pan,13mm Ethos,6-3 Nagler Zoom
Celestron Power Tank 17
Astro-Tech Voyager Mount
Celestron SLT Mount
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YankeeJeff
professor emeritus
Reged: 08/11/06
Posts: 537
Loc: Brooklyn, NY
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I picked up the wayfinder v7000 for 50 bucks from overstock.com it's supposed to be accurate to 1 degree and I can set to true or magnetic north. I'll let you folks know how it works out. I don't really need it but I think it may be a cool looking gizmo to add on that also gives me the weather and some other neat tricks.
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Oh let the sun beat down upon my face, stars to fill my dream
I am a traveler of both time and space, to be where I have been
24Pan, 17T4, 13T6, 11T6, 9BTMB, 8TVpl, 7T6, 5T6, 3.5T6, 5/6BTMBs
Z10"Dob, Paracorr, 2xBrlw, Telrad, RACI,°Circles, )Spider
FBF, Brooklyn: 
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YankeeJeff
professor emeritus
Reged: 08/11/06
Posts: 537
Loc: Brooklyn, NY
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Update: Received and installed the Wayfinder v7000. IMHO, it does an excellent job (accurate to 1 degree + true or magnetic North settings). With the $9 Home Depot inclinometer and the Wayfinder 7000 digital compass ($50 refurbished from Overstock.com) the total system is about $60. If the digital SmartTool price drops enough maybe I'll get that too. Not a bad overall price for the results. It also works and I find it a bit easier to use. The down side - it costs more and defeats the purpose of doing this on a budget.
In any case, I will keep the setting circles on the scope just in case I'm ever observing in a location w/ strong magnetic interference. I can't thank you folks enough for the threads on this subject - it makes life a whole lot easier AND saves money! 
--------------------
Oh let the sun beat down upon my face, stars to fill my dream
I am a traveler of both time and space, to be where I have been
24Pan, 17T4, 13T6, 11T6, 9BTMB, 8TVpl, 7T6, 5T6, 3.5T6, 5/6BTMBs
Z10"Dob, Paracorr, 2xBrlw, Telrad, RACI,°Circles, )Spider
FBF, Brooklyn:
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Curt B
super member
Reged: 08/02/05
Posts: 191
Loc: Regina, Canada
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Thanks for the update....i just might get one too!
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TV 85
GSO 30 & 26mm 2" eyepieces
24mm Pan,13mm Ethos,6-3 Nagler Zoom
Celestron Power Tank 17
Astro-Tech Voyager Mount
Celestron SLT Mount
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chmee
super member
Reged: 05/11/05
Posts: 158
Loc: Takoma Park, MD
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Quote:
Update: Received and installed the Wayfinder v7000. IMHO, it does an excellent job (accurate to 1 degree + true or magnetic North settings). With the $9 Home Depot inclinometer and the Wayfinder 7000 digital compass ($50 refurbished from Overstock.com) the total system is about $60.
Wow, this I really didn't expect. Did you really give the compass a workout? I realize that it reads out in 1 degree increments, but does it repeatedly give the same value for the same orientation (place it against a wall, read, spin it a bit and place it back against the wall, read again)?
What about the backlight, can you keep the display on and backlight off for more than a minute or so?
I've already ordered the smartttool ($90 at amazon w/ an automatic discount) w/ the intent of replicating Rod Nabholz's setup. If this really works, I'd order it in a minute.
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16" dob
ED80sf
15x50 IS binocs
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YankeeJeff
professor emeritus
Reged: 08/11/06
Posts: 537
Loc: Brooklyn, NY
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When I started using the compass tonight it was a little off. I had to recalibrate (takes about 30 seconds). This entails pressing the menu button once, pressing enter, spinning the base of the scope one full revolution, then repressing menu. I took off the suction cups of the compass and drilled it into the base to make it nice and tight. I also tightened the adjustment screw on swivel/tilt so that it basically can't move out of it's horizontal position. This also allows me to press the buttons without fear of knocking the compass out of it's holder. Your supposed to keep the compass (made for your car) in the same place w/in your car, thus I want to keep it in the same position on my scope.
Which brings me to one of the questions above: Did I Quote:
place it against a wall, read, spin it a bit and place it back against the wall, read again
... the answer is no.
Again, I screwed the plastic compass holder into the base (the compass itself can be removed from the holder but I don't move it). On the contrary, I keep it nice and tight on the holder at a horizontal position with the base for most accuracy.
Before viewing I simply calibratrate, make sure magnetic declination is set, and then generally keep the bottom base in place as I slew the scope. I do occassionally move the entire telescope unit around the house from one window to another) and it doesn't seem to affect results. How it works outside I don't know yet. Maybe I'll test it this weekend if the weather permits. For now it seems to be working in my home. I'm finding things very quickly.
Generally the target objects (using starry night & skycharts software) are found within the FOV of my 32mm eyepiece. Once in a while they are slightly off and it takes a nudge on the AZ setting to get it in the FOV. Usually this happens because the AZ coordinate lies almost directly between two 1 degree increments (e.g. 87.467 degrees) - add that to the rounded off declination and you may be off about 1.5 degree total at times. All in all I can live with that. I'm happy with it thus far. I'll keep you posted and report any problems.
FYI - the backlight can stay on up to 3 minutes and when the backlight goes off, the unit stays on a bit longer before the auto shut off kicks in. The compass is plastic. I think this little unit is ideal for my situation because I don't have to fuss w/ Polaris or anything -which is good for me since I can't see it from my window.
--------------------
Oh let the sun beat down upon my face, stars to fill my dream
I am a traveler of both time and space, to be where I have been
24Pan, 17T4, 13T6, 11T6, 9BTMB, 8TVpl, 7T6, 5T6, 3.5T6, 5/6BTMBs
Z10"Dob, Paracorr, 2xBrlw, Telrad, RACI,°Circles, )Spider
FBF, Brooklyn:
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Gigatron
professor emeritus
Reged: 12/10/05
Posts: 650
Loc: Staten Island, N.Y.
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Hey Jeff,
Got a couple of questions for ya.
1) do you think the v700 would work well in place of the v7000? The difference seems to be the thermometer and barometer. I don't think I really need those to see a star, as long as the compass is just as accurate.
2) how did you mount it to your scope? any pictures?
3) have a part number on that inclinometer?
Thanks,
Fred
--------------------
Meade ETX-90 UHTC, AutoStar 497,
Right angle viewfinder
Deluxe field tripod
Zhumell 10" dob
Telrad finder
GSO 8x50 RACI finder
Too many special modifications to list
2" 32mm GSO,
9mm GSO,
26mm,15mm,12.4mm,6mm Meade SP,
5mm,7mm,9mm Burgess/TMB planetary
Meade 2X Barlow
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kestrel0222
Carpal Tunnel
Reged: 05/21/06
Posts: 2338
Loc: Milford, Michigan
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Jeff,
Are you able to set north to Polaris? How do you calibrate it to correspond with computer generated azimuth coordinates? It all sound good.
--------------------
Tom
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YankeeJeff
professor emeritus
Reged: 08/11/06
Posts: 537
Loc: Brooklyn, NY
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Fred
1)The v700 gives the read-out in 5 degree increments. IMHO, this is not enough. I believe the v7000 unit has both critical components, namely the ability to correct for magnetic declination, as well as, giving read-outs in one (1) degree increments. There could be other units out there that have those same capabilites without the other bells and whistles for cheaper - I'm not sure.
2)I don't have the ability to post pictures right now.
Basically I screwed the compass into the swivel base board (toward the rear-end of the scope and directly opposite the front of the scope with the handle). If you can imagine placing the degree circle on the base board with zero (0) in the front - the compass would be screwed into EXACTLY where the 180 degree mark would be in the back. The compass should be screwed in tightly to the base. According to the instructions you can tilt the unit up or down within it's swivel bracket a maximum of 20 degrees but I found that not having a tilt at all is most accurate. Whatever angle you select for the tilt, the compass must stay that way (otherwise you'll have to recalibrate), thus I also tightened the side adjustment screw for the angle of the tilt so it doesn't accidently get bumped out of it's bracket.
3)The inclinometer was purchased at Home Depot (you won't find it on their website). It is an "EMPIRE magnetic polycast protractor" that can be purchased for a little less than $9.
Tom
I do not need to set North to Polaris - North is set magnetically by the compass and adjusted for magnetic declination. Once I turn on the compass and calibrate it (by pressing a button and spinning it in place one full revolution), I'm set to slew the scope to the coordinates I get from my planetarium software.
--------------------
Oh let the sun beat down upon my face, stars to fill my dream
I am a traveler of both time and space, to be where I have been
24Pan, 17T4, 13T6, 11T6, 9BTMB, 8TVpl, 7T6, 5T6, 3.5T6, 5/6BTMBs
Z10"Dob, Paracorr, 2xBrlw, Telrad, RACI,°Circles, )Spider
FBF, Brooklyn:
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Gigatron
professor emeritus
Reged: 12/10/05
Posts: 650
Loc: Staten Island, N.Y.
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Thanks for the answers, Jeff. Just one more quick question, is there a particular reason that you mounted the compass where you did, or can it be put anywhere?
I mean, I have no problem mounting it at the rear, I'm just wondering if there's a reason.
Thanks,
Fred
--------------------
Meade ETX-90 UHTC, AutoStar 497,
Right angle viewfinder
Deluxe field tripod
Zhumell 10" dob
Telrad finder
GSO 8x50 RACI finder
Too many special modifications to list
2" 32mm GSO,
9mm GSO,
26mm,15mm,12.4mm,6mm Meade SP,
5mm,7mm,9mm Burgess/TMB planetary
Meade 2X Barlow
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YankeeJeff
professor emeritus
Reged: 08/11/06
Posts: 537
Loc: Brooklyn, NY
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I could be wrong, but I thought it would give me the most accurate reading -esp. when I'm trying to get down to 1 degree. Its placement mimics the finderscope placement - kind of like splitting the primary and seconday. When you step behind to read the display, its like you would in your car, i.e. looking at the compass display which gives the reading of the direction directly in front of you as you drive.
I guess it may be more convenient to place it to the left of the scope so I can just look down and take a quick read before peeking into the eyepiece but intuitively I'm thinking that wouldn't work. I guess you could try that out and test with a sky object. If it were not accurate, you might then readjust the declination to compensate. I'm not sure.
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Oh let the sun beat down upon my face, stars to fill my dream
I am a traveler of both time and space, to be where I have been
24Pan, 17T4, 13T6, 11T6, 9BTMB, 8TVpl, 7T6, 5T6, 3.5T6, 5/6BTMBs
Z10"Dob, Paracorr, 2xBrlw, Telrad, RACI,°Circles, )Spider
FBF, Brooklyn:
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Gigatron
professor emeritus
Reged: 12/10/05
Posts: 650
Loc: Staten Island, N.Y.
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Well, here's my thinking on this; as long as the compass is facing forward (i.e. same direction scope is pointing), the readings should be just as accurate. 87* is 87* either under, above or along side the scope.
The only time I can see there being a problem, regardless of where the compass is placed, is when the object is at zenith.
When I get one, I'll mount it temporarily and see what happens if it's mounted along side the scope.
-Fred
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Meade ETX-90 UHTC, AutoStar 497,
Right angle viewfinder
Deluxe field tripod
Zhumell 10" dob
Telrad finder
GSO 8x50 RACI finder
Too many special modifications to list
2" 32mm GSO,
9mm GSO,
26mm,15mm,12.4mm,6mm Meade SP,
5mm,7mm,9mm Burgess/TMB planetary
Meade 2X Barlow
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chmee
super member
Reged: 05/11/05
Posts: 158
Loc: Takoma Park, MD
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Jeff.
I think the only real question is whether the compass will give precise, repeatable directions. I'm definitely looking forward to hearing your experience. Around here (DC), at least, we're going to get the first decent night in weeks tomorrow. Hope you have it as well.
I was thinking about the backlight. This is probably not a problem, as the screen could be covered by a red film.
pete
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16" dob
ED80sf
15x50 IS binocs
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YankeeJeff
professor emeritus
Reged: 08/11/06
Posts: 537
Loc: Brooklyn, NY
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Update2: Believe it or not, I haven't yet had the opportunity to test the digital compass outside (Floyd Bennett Field is where I would go). The opportunity to step outside has been elusive and to be honest - it's nice and comfy inside and I've been learning a lot from the comfort of my own home.  So, thus far I've had about 4 or 5 nights of testing indoors.
When I turn on the compass at the beginning of my viewing session, sometimes it puts an object in the FOV or sometimes it's accurate to about 1 or 2 degrees and requires some nudging to find the object. Thus far it has always been in the ballpark (under 5 degrees).
However, if I do a lot of moving around, which I usually do because of obstructions in the home and the limitation of window angles, it may eventually throw off accuracy by 5 degrees. Unfortunately, I've seen it get as bad as 8 degrees. I end up resetting the compass about 3 times a full night (i.e. 9pm - 5am). I also have a lot of electronic equipment around so I think it may contribute to throwing the thing off. In any case, even when it's off, I know I'm basically looking on the azimuth plane only so nudging is usually over quick.
So... I'm able to live with this non-precise degree of accuracy because it's tough for me sometimes to see Polaris (i.e. girlfriend won't give up the bedroom for the night!), and thus calibrating with other stars takes even longer for me. I would ideally need to test outside. When I'm at my outdoor spot, I'm basically planted in one area and just turn the scope's tube - I'm pretty sure it will work better in that scenario.
Until then, I'm not convinced this is the rock solid digital solution most are looking for. Perhaps there are better digital solutions out there that won't break the bank. It does happen to have a time advantage on the azimuth for me right now. This makes me appreciate that very accurate Home Depot inclinometer that much more. Also, I finally got my Telrad so the combo of finder-scope, Telrad, and this budget 'push-to' system seems to work well enough for me. Again - my humble thanks to the folks who started this thread and have therefore saved me time and money. Oh, and my apologies for folks who ran out and purchased a Wayfinder 7000 and may not be thrilled about it 
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Oh let the sun beat down upon my face, stars to fill my dream
I am a traveler of both time and space, to be where I have been
24Pan, 17T4, 13T6, 11T6, 9BTMB, 8TVpl, 7T6, 5T6, 3.5T6, 5/6BTMBs
Z10"Dob, Paracorr, 2xBrlw, Telrad, RACI,°Circles, )Spider
FBF, Brooklyn:
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chmee
super member
Reged: 05/11/05
Posts: 158
Loc: Takoma Park, MD
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Quote:
Oh, and my apologies for folks who ran out and purchased a Wayfinder 7000 and may not be thrilled about it
Too late!
I had the smart tool for altitude, so decided to try the compass for azimuth. I was hoping for 2 or 3 degrees max, figured it was only $40 if not. I did not quite expect 8 degrees.
At any rate, given both devices, I mounted them on my scope last night and took it out to the driveway. I had more confidence w/ the inclinometer (smart tool), as others have used it successfully. W/ the wayfinder I had several concerns: 1) accuracy, 2) backlight, and 3) directionality.
For accuracy, concerns were justified. I calibrated the wayfinder and then used the magnetic declination setting to zero on polaris. I then tried to use the two to find things, with mixed success. My first attempt, M31, was off by 3 degrees of azimuth. M76 was found in the eyepiece (40mm, about 1.5 degrees). M92 two degrees off. Several stars were within a couple degrees azimuth, but two were four degrees off, and one was eight.
Interestingly, when I finally rotated all the way around, polaris was only one degree off. I'm speculating that the "map" of the surroundings the wayfinder makes during calibration is off. Perhaps this was because I didn't do it evenly enough or some such.
Another interesting point that didn't occur to me until afterwards was that I think the error was always in the same direction (of azimuth). If so, this would significantly ease the process. After all, searching in one dimension is much easier than searching in two.
As far as the smart tool, it was always within two or three tenths, at most.
My second concern was the wayfinder's backlight. Turns out this is not bright, is easily disabled, and actually somewhat useful. The wayfinder has to be mounted down on the rocker base, so it's a bit hard to see from up near the eyepiece. Situation might be different when I get to a dark site.
My last concern was directionality, by which I mean that the wayfinder is designed to be mounted on a dashboard, facing forward. Facing the compass in the directy my mount is facing would mean mounting in on the "back", i.e., I'd have to get off the chair and walk around the scope to read it. I put the wayfinder on the side of the scope, meaning that it's 90 degrees off, PLUS the magnetic declination. The wayfinder's magnetic declination can be set up to 99 degrees, which would seem to be enough. However, it didn't seem that way, I seemed to need more like 105. So I left it at 95, meaning that I have to add 10 to each azimuth I look up on the computer. No big deal.
Overall, it's good enough that I'm willing to spend another couple of evenings trying to work out the kinks. If I can't, I'll mount the wayfinder in my car and add a printed azimuth circle to the base (which will be a bit of a pain).
Cheers,
pete
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16" dob
ED80sf
15x50 IS binocs
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YankeeJeff
professor emeritus
Reged: 08/11/06
Posts: 537
Loc: Brooklyn, NY
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*Gosh, dang dibbity dag nabbit* - sorry Pete. That first night it was only off max 1.5 degrees. It was w/ the longer nights that I saw how bad it could get at times. Now that I think about it, I was limited to a smaller part of the sky. Maybe your right about the direction of error and it’s not the 'moving around' that causes the errors as I thought it might be. I've got to check that out some more myself. Hope you work out the kinks.
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Oh let the sun beat down upon my face, stars to fill my dream
I am a traveler of both time and space, to be where I have been
24Pan, 17T4, 13T6, 11T6, 9BTMB, 8TVpl, 7T6, 5T6, 3.5T6, 5/6BTMBs
Z10"Dob, Paracorr, 2xBrlw, Telrad, RACI,°Circles, )Spider
FBF, Brooklyn:
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chmee
super member
Reged: 05/11/05
Posts: 158
Loc: Takoma Park, MD
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Quote:
*Gosh, dang dibbity dag nabbit* - sorry Pete. That first night it was only off max 1.5 degrees.
Don't worry, I'm just messing w/ you. I'm a gadget freak and had to try it out. Might still work. Unfortunately, weather doesn't look promising here, plus the moon situation, so it might be a couple weeks.
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16" dob
ED80sf
15x50 IS binocs
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kingjamez
scholastic sledgehammer
Reged: 10/03/06
Posts: 991
Loc: Washington D.C.
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First, thanks to all the contributors to this great idea. This is the best thing that has happened to me since I got started in astronomy.
Here's my question. I just got the system setup with skyarchers circle and an inclinometer (I found the Harbor Freight one the best). I'm using Planetarium for Palm. When I set Planetarium to AzM for Azimuth taking into account the earths magnetic offset, and then use a compass to calibrate the scope, it is always off. However if I use a compass to calibrate north and then turn the magnetic offset off, it works fine?
I'm not complaining since the system works, just curious if anybody knows why this is happening.
I live in Washington D.C. and the Magnetic Offset according to every place I've seen is about 11 degrees.
-Jim
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C8 on Atlas with EQMOD
ETX125 UHTC
Celestron Onyx 80mm
Meade Walmart 60mm guide scope
Canon Xsi Modified w/IDAS LPR
Gen 3 NightVision Eyepiece
Aspiring Optician
Watch my Wiimote control Atlas:
http://www.youtube.com/watch?v=PnmkygmGNiM
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csa/montana
Den Mother
Reged: 05/14/05
Posts: 39606
Loc: montana
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Jim: What I do is center Polaris, then move the "needle" (magnet on metal strip) to zero. From then on, it is extremely accurate. I don't use a compass at all. But if you have yours working, it doesn't matter how, just so it does work for you to benefit from the ease in which to find those elusive targets, especially when there are no bright stars nearby for placement. Have fun!
Carol
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Carol
AstroTech 16" Dob (Thanks ASTRONOMICS!)
Vixen 80MF/AstroTech Voyager
Masuyama's 7.5, 15, 25W, 35mm,
Pentaxes; 5XW, 7XL, 10XW.
14mm Meade 4000 UWA
TV Panoptics; 22, 35
DreamCatcher Dobservatory, #2
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kingjamez
scholastic sledgehammer
Reged: 10/03/06
Posts: 991
Loc: Washington D.C.
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Ok, I figured it out. I had the time on my PDA set 1 hour ahead, which for the sun was about the same as the magnetic north offset. When I took it out tonight, I found the error and fixed it.
Wow... I have street lights all around me, I live in a townhouse with neighbors who don't turn off their patio lights. I can't even see polaris. However with the $12.00 "push-to" I was able to find things I've never found from my house before. In less than an hour with NO finderscope (including setup and discovery of the time error) I found:
M31
M32
M34
M27
M13
M92
All of these were either in my field of view or very close to it (using a truly Dobson 7x50 binocular eyepiece from a broken pawnshop pair). I could have hit more very quickly, but LOST was coming on.
I can now really stargaze from my backyard...even though I can't see polaris becuase of the light pollution!
Thank you Carol, Rod, and SkyArcher!!!
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C8 on Atlas with EQMOD
ETX125 UHTC
Celestron Onyx 80mm
Meade Walmart 60mm guide scope
Canon Xsi Modified w/IDAS LPR
Gen 3 NightVision Eyepiece
Aspiring Optician
Watch my Wiimote control Atlas:
http://www.youtube.com/watch?v=PnmkygmGNiM
Edited by kingjamez (10/25/06 10:52 PM)
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Laramie
member
Reged: 09/03/06
Posts: 12
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Carol Can you please tell me who did the circles for you. I like the set up and would love to do the same on my dob.
Thanks in advance
Becky
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csa/montana
Den Mother
Reged: 05/14/05
Posts: 39606
Loc: montana
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For anyone interested in the pdf file from SkyArcher for the degree circles; here is the file:
http://www.cloudynights.com/ubbthreads/attachments/944499-Alt-AZ_Setting_Circle.pdf
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Carol
AstroTech 16" Dob (Thanks ASTRONOMICS!)
Vixen 80MF/AstroTech Voyager
Masuyama's 7.5, 15, 25W, 35mm,
Pentaxes; 5XW, 7XL, 10XW.
14mm Meade 4000 UWA
TV Panoptics; 22, 35
DreamCatcher Dobservatory, #2
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GordonCopestake
Carpal Tunnel
Reged: 03/02/06
Posts: 2714
Loc: Newcastle-under-Lyme, UK
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Someone kindly sent me a 24" one for my 12" lightbridge
http://www.copestake.org/24DialWhite.pdf for those interested in making setting circles for a 12" lightbridge
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http://www.wareforge.com
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Stefan Rostyne
Pooh-Bah
Reged: 10/19/04
Posts: 1009
Loc: Assenede, Belgium
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thx, Gordon!
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Stefan Van de Rostijne
4.5" F4.5 newt 5°widefield/finderscope
8" f/5.6 travel dob
old 12.5" F5 dob (used to look better...)
30 cm f/30 Classic Cassegrain (polishing primary)
23" f/4 dob project
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csa/montana
Den Mother
Reged: 05/14/05
Posts: 39606
Loc: montana
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Gordon: Thanks so much for posting the pdf for a 12" LightBridge; now if someone would post one for a 10" base, it would help those with that size.
Again, thanks for your kind addition!
Carol
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Carol
AstroTech 16" Dob (Thanks ASTRONOMICS!)
Vixen 80MF/AstroTech Voyager
Masuyama's 7.5, 15, 25W, 35mm,
Pentaxes; 5XW, 7XL, 10XW.
14mm Meade 4000 UWA
TV Panoptics; 22, 35
DreamCatcher Dobservatory, #2
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kestrel0222
Carpal Tunnel
Reged: 05/21/06
Posts: 2338
Loc: Milford, Michigan
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Carol,
As was mentioned earlier in this post, all one would have to do is to figure out what scale factor they would need to make it to the appropriate size that they would need for their particular base size.
However, I had so much trouble trying to get the original PDF file (that SkyArcher made) to the right scale, that I designed my own for my 12” DSO. The problem WAS NOT with SkyArcher's file; the problem was with Kinko’s getting it done for me. They tried numerous times and NEVER got it right. That was when I decided to do it myself. I made the circle to the exact size that I wanted for my scope. That is the PDF file that Gordon posted.
I was reading the post that Gordon had posted in regards to his new 12" Lightbridge, he mentioned that he needed a circle that would fit his base, I thought, well, I have one that I made that worked for me, why not pass it on.
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Tom
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csa/montana
Den Mother
Reged: 05/14/05
Posts: 39606
Loc: montana
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Tom: Thank You!! There are many 12" Dob owners out there that will love you for this great addition to this link!
Again, my friend, many, many thanks for your contributions!
Carol
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Carol
AstroTech 16" Dob (Thanks ASTRONOMICS!)
Vixen 80MF/AstroTech Voyager
Masuyama's 7.5, 15, 25W, 35mm,
Pentaxes; 5XW, 7XL, 10XW.
14mm Meade 4000 UWA
TV Panoptics; 22, 35
DreamCatcher Dobservatory, #2
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kestrel0222
Carpal Tunnel
Reged: 05/21/06
Posts: 2338
Loc: Milford, Michigan
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Thanks Carol,
The circle that I made was designed to be placed on the bottom board (numbers in a clockwise direction). This requires that a small notch (I made mine 2” X 5”) to be made at the edge of the top board to view the circle thru. However, if anyone wants (or needs) one made to be places on the top board (numbers in a counter clockwise direction - 24" diameter), let me know, I will gladly make it for them.
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Tom
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csa/montana
Den Mother
Reged: 05/14/05
Posts: 39606
Loc: montana
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Tom: Again, thanks for your contributions, you rock! 
Carol
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Carol
AstroTech 16" Dob (Thanks ASTRONOMICS!)
Vixen 80MF/AstroTech Voyager
Masuyama's 7.5, 15, 25W, 35mm,
Pentaxes; 5XW, 7XL, 10XW.
14mm Meade 4000 UWA
TV Panoptics; 22, 35
DreamCatcher Dobservatory, #2
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GordonCopestake
Carpal Tunnel
Reged: 03/02/06
Posts: 2714
Loc: Newcastle-under-Lyme, UK
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i wasn't sure if you wanted to be named Tom, but once again, thanks for the circle! Very much appreciated!
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http://www.wareforge.com
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kestrel0222
Carpal Tunnel
Reged: 05/21/06
Posts: 2338
Loc: Milford, Michigan
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You are very welcome, Gordon. I'm just glad that I could help.
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Tom
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darklighteditor
Theatre King
Reged: 11/07/06
Posts: 3853
Loc: Tawas Bay, Michigan
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Carol - I finally got around to reading your Degree Circles thread (due to lack of time, not desire) and from my initial read-through, what a great idea for the $12 "Push-To".
It seems like this would be an absolute "must have" for anyone with a Dob.
I have extra some vacation time I've accumulated which I'm taking off between Christmas and New Years, so that will give me time to tinker with it.
Unfortunately, we don't have a Kinkos or such nearby, so I'll be printing the plans separately on a 11- by 17-inch paper printer (which I'll have to figure out how to do it "piece-meal" by overlap). Luckily, I have a large laminator here at work.
I also plan to print out the thread and read it over closely, but I suspect you'll be hearing from me as I move along the process (I'm certainly not an engineer, but I have a knack for figuring things out - albeit sometimes slowly ).
John
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John
8" f/6 DBA Dob: 8X50 RACI, 2-speed Crayford
1.25": 25mm, 9mm GSO Plossls; 15mm, 20mm GSO SV;
5.7mm Antares W70; 8mm Hyperion.
2": 30mm GSO SV; 2X barlow.
Zhumell green laser light, Lumicon mount
UltraBlock, Oxygen III & DeepSky filters
"I am not the editor of a newspaper. And I shall always try to do right and be good, so that God will not make me one." - Mark Twain
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csa/montana
Den Mother
Reged: 05/14/05
Posts: 39606
Loc: montana
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John: Thank you! It is such a wonderful, very inexpensive method. The best part, you can do it yourself. I've had a great time with it.
When you get ready, just fire away, & we will get you thru setting it up.
I've enjoyed so much, reading the posts from others that have employed this idea. That's what it's all about, sharing & helping!
Carol
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Carol
AstroTech 16" Dob (Thanks ASTRONOMICS!)
Vixen 80MF/AstroTech Voyager
Masuyama's 7.5, 15, 25W, 35mm,
Pentaxes; 5XW, 7XL, 10XW.
14mm Meade 4000 UWA
TV Panoptics; 22, 35
DreamCatcher Dobservatory, #2
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darklighteditor
Theatre King
Reged: 11/07/06
Posts: 3853
Loc: Tawas Bay, Michigan
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Thanks Carol!
I'm sure you'll be hearing from me.
And looking at my continously white CSC, I may be getting to that quicker than expected. Ya know, this weather has been something else this fall (and now heading into winter). Since I've received the 8-inch Dob from DBA exactly one month ago today, I've had a total of six nights viewing - that's 24 cloudy nights in a 30-day span. Percentage wise, it can't get any worse, can it??? I think this "Curse" has outlived its usefulness on my end. On the bright side, perhaps I'm simply getting the worse weather out of the way early...
John
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John
8" f/6 DBA Dob: 8X50 RACI, 2-speed Crayford
1.25": 25mm, 9mm GSO Plossls; 15mm, 20mm GSO SV;
5.7mm Antares W70; 8mm Hyperion.
2": 30mm GSO SV; 2X barlow.
Zhumell green laser light, Lumicon mount
UltraBlock, Oxygen III & DeepSky filters
"I am not the editor of a newspaper. And I shall always try to do right and be good, so that God will not make me one." - Mark Twain
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csa/montana
Den Mother
Reged: 05/14/05
Posts: 39606
Loc: montana
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John, I agree about the weather; ordinarily, here we have many more clear skies than cloudy, but this Fall, up to now, it's been about 90% cloudy, 10% clear.
Perhaps we should all hide our scopes, & then sneak them out before the evil clouds see us!
Carol
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Carol
AstroTech 16" Dob (Thanks ASTRONOMICS!)
Vixen 80MF/AstroTech Voyager
Masuyama's 7.5, 15, 25W, 35mm,
Pentaxes; 5XW, 7XL, 10XW.
14mm Meade 4000 UWA
TV Panoptics; 22, 35
DreamCatcher Dobservatory, #2
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GordonCopestake
Carpal Tunnel
Reged: 03/02/06
Posts: 2714
Loc: Newcastle-under-Lyme, UK
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You should come live in england hehe, it's 10% clear and 90% cloudy ALL the time!
And just to rub it in all our kit costs TWICE as much as yours hehe
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http://www.wareforge.com
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csa/montana
Den Mother
Reged: 05/14/05
Posts: 39606
Loc: montana
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Plus you have that Damp cold!!!
Carol
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Carol
AstroTech 16" Dob (Thanks ASTRONOMICS!)
Vixen 80MF/AstroTech Voyager
Masuyama's 7.5, 15, 25W, 35mm,
Pentaxes; 5XW, 7XL, 10XW.
14mm Meade 4000 UWA
TV Panoptics; 22, 35
DreamCatcher Dobservatory, #2
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nitroexpress
professor emeritus
Reged: 12/16/06
Posts: 538
Loc: Hemet, calif
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Carol:....
Thank you for your posts on the degree circles. Best thing since the invention of sliced bread......it made my 10" z10 into a push-to great scope.....i am using HNSKY for the computer ( laptop).....works well........thanks again for the best idea on the net....and to skyarcher for the degree wheel..................gary
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"Life is not measured by the number of breaths we take but by the moments that take our breath away."
10in Zhumell-$15/ push to circles-flocked tube
8in-c8-on a Meade GoTo EQ mount with a cg-5 Tripod
5in Meade with goto...
2in Gilbert reflector (1955 or so)
7x35 binos
Orion 100mm X 600mm Achromatic Refractor
Sac8-2 ccd camera
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csa/montana
Den Mother
Reged: 05/14/05
Posts: 39606
Loc: montana
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Gary: A very Warm Welcome to Cloudy Nights! You have joined a great group here.
I'm so glad you are enjoying the setup. It's so simple, I'm sure many feel "No way can it work accurately"; but that's the great thing, simplicity equals accuracy!
If you have any questions, please don't hesitate to ask, we love answering questions, because that is how we learn also.
Again, Welcome aboard, & a very big thank you for taking the time to let me know about your success with the degree circles!
Carol
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Carol
AstroTech 16" Dob (Thanks ASTRONOMICS!)
Vixen 80MF/AstroTech Voyager
Masuyama's 7.5, 15, 25W, 35mm,
Pentaxes; 5XW, 7XL, 10XW.
14mm Meade 4000 UWA
TV Panoptics; 22, 35
DreamCatcher Dobservatory, #2
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drzeus
member
Reged: 01/11/05
Posts: 84
Loc: Athens, Greece
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The simplest ideas often work the best! I have followed this thread with interest having first come across this idea in Rod's web pages.
Electronic digilevels I looked at but were far too expensive for me. So while trying to find a placky inclinometer I was browsing Lidl's pages at the same time and spotted a digital spirit level. OK. the downside is that it is almost two feet in length, but the good thing is the digital unit screws out of the level itself! (Just as soon as I find my Allen keys!)Beeps every 10 degrees and has soft blue backlight that can be turned off. On the first very rough test I tried (holding the level gingerly along Dob tube!) it seemed pretty accurate. Just got to get the circle for the base printed off now.
All for a grand ... 29.99 euros! Lidl do their offers on a rotation basis each year so no doubt it will pop up again in the near future, for anyone wanting to track the unit down. FYI its got Paget Trading UK on it. Lidl are great for things like that, if you can manage to get there before all the retired people! (No offence intended!)
Anyway great job folks ... I just wanted to say thanks for telling us all about such a great simple idea.
(Today here in Athens, Lidl have Meade ETX70 GOTO, with backpack (which I saw for 55 pounds alone!), for 199 euros ... but I am being very good and keeping my hands in my pockets!)
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Higher always be your dreams and desire, to which you aspire,
Higher always, higher always.
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Terry1229
super member
Reged: 04/16/06
Posts: 144
Loc: North, Idaho
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I printed mine from a program i got of of this thread. It printed on to about 6 sheets of paper, then I glued them to some foamboard and cut it out. I am still in the process of finishing. I need to put a clear coat over the top.
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Terry:
A 6" f8 dob with 14mm Anteres eyepiece
Wixey
Homemade EQ & stepper
QC pro4000
spc900
homemade ele. focuser
New [used] Meade 8" sc ota
New [used]] CG5
Edited by Terry1229 (12/21/06 01:57 PM)
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GordonCopestake
Carpal Tunnel
Reged: 03/02/06
Posts: 2714
Loc: Newcastle-under-Lyme, UK
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they sell those digital levels on ebay. Not as cheap as lidl but still pretty good.
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http://www.wareforge.com
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csa/montana
Den Mother
Reged: 05/14/05
Posts: 39606
Loc: montana
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Terry, it's looking great!
Let us know when you try it out!
Carol
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Carol
AstroTech 16" Dob (Thanks ASTRONOMICS!)
Vixen 80MF/AstroTech Voyager
Masuyama's 7.5, 15, 25W, 35mm,
Pentaxes; 5XW, 7XL, 10XW.
14mm Meade 4000 UWA
TV Panoptics; 22, 35
DreamCatcher Dobservatory, #2
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Mike Moffatt
scholastic sledgehammer
Reged: 07/13/05
Posts: 856
Loc: Broken Arrow, Oklahoma
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Quote:
Beeps every 10 degrees and has soft blue backlight that can be turned off.
Make a small red filter cover for it just like we all do for our laptops.
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Mortal as I am, I know that I am born for a day. But when I follow at my pleasure the serried multitude of the stars in their circular course, my feet no longer touch the earth.
- Ptolemy,c.150 AD
Mike Moffatt
6" f8 Coopered Newt/Dob
15x70 Celstron Skymasters
www.tulsawalk.com/telescope
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drzeus
member
Reged: 01/11/05
Posts: 84
Loc: Athens, Greece
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Will do!
I assume this sort of gadget isn't affected if it gets a magnetic strip stuck on it so I can clip it to my scope tube? I know Rod's is held on magnetically ... I have no idea how these actually work or if anything in it can be affected by magnets. I only know there is so much metal in our building I cannot use a compass to line up so will have to go by visual sighting -hopefully using Polaris- to align everything.
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Higher always be your dreams and desire, to which you aspire,
Higher always, higher always.
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rnabholz
scholastic sledgehammer
Reged: 07/25/04
Posts: 897
Loc: Iowa
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Quote:
Will do!
I assume this sort of gadget isn't affected if it gets a magnetic strip stuck on it so I can clip it to my scope tube? I know Rod's is held on magnetically ... I have no idea how these actually work or if anything in it can be affected by magnets. I only know there is so much metal in our building I cannot use a compass to line up so will have to go by visual sighting -hopefully using Polaris- to align everything.
Just by way of clarification, my digital level is held on its mounting bracket by velcro. It was the original analog inclinometer that was magnetically mounted.
Clear skies.....
Edited by rnabholz (12/22/06 10:13 PM)
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Roger51
member
Reged: 09/05/06
Posts: 61
Loc: Michigan
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Interesting thread. Could someone point me to the PDF file, I don't see it?
Thanks
RS
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Roger
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Roger51
member
Reged: 09/05/06
Posts: 61
Loc: Michigan
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Never mind found them...thx
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Roger
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csa/montana
Den Mother
Reged: 05/14/05
Posts: 39606
Loc: montana
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Roger: Welcome, sorry I didn't see you post in time to get you to the pdf file, glad you found it.
Any questions, just ask, we love to help!
Carol
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Carol
AstroTech 16" Dob (Thanks ASTRONOMICS!)
Vixen 80MF/AstroTech Voyager
Masuyama's 7.5, 15, 25W, 35mm,
Pentaxes; 5XW, 7XL, 10XW.
14mm Meade 4000 UWA
TV Panoptics; 22, 35
DreamCatcher Dobservatory, #2
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drzeus
member
Reged: 01/11/05
Posts: 84
Loc: Athens, Greece
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UK residents looking for cheap digital meter - Lidl has one coming up for sale from 11/1 for 24.99 UK pounds.
Having got Allen keys as a Christmas present (how sad?!) I have now released meter from the level!!
Thanks for the correction Rod. I played with the magnets around the meter and it didnt appear to affect it but I may have to use velcro anyway since I hid my magnets away so toddler wouldn't find them - now can't remember where they are!
Now waiting for some clear skies!
Happy New Year to all - let's hope we see some great things this year!
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Higher always be your dreams and desire, to which you aspire,
Higher always, higher always.
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csa/montana
Den Mother
Reged: 05/14/05
Posts: 39606
Loc: montana
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D:rzeus: Happy New Year to you! Well, Allen keys, hmmm, they did let you release the meter from the level, didn't they?
Let us know how your "push-to" system goes.
Carol
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Carol
AstroTech 16" Dob (Thanks ASTRONOMICS!)
Vixen 80MF/AstroTech Voyager
Masuyama's 7.5, 15, 25W, 35mm,
Pentaxes; 5XW, 7XL, 10XW.
14mm Meade 4000 UWA
TV Panoptics; 22, 35
DreamCatcher Dobservatory, #2
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darklighteditor
Theatre King
Reged: 11/07/06
Posts: 3853
Loc: Tawas Bay, Michigan
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Carol - Your $12 "Push-To" is right on the mark - That's exactly what I paid for mine! Although I must say working I for a newspaper did some some advantages.
While I gathered all of the needed materials during my week's vacation between Christmas and New Year, I wasn't able to complete the project until last night (too many "honey-do" projects around the house!).
First, I printed the degree circles at work. We don't have a printer quite large enough to print the entire 19-inch circle, so I ended up doing it "piece meal" in thirds. We have an old light table (from our old "hot wax" days of pasting up the newspaper prior to pagination) so I was able to carefully align the three pieces. Luckily, we also have a double-sided laminator.
I affixed the circle to the base with double-sided duct tape (yes, duct tape - it's a guy thing!)
We also had some strapping steel laying around at work so I used about eight inches of that on the front of the bottom base board attached with three stainless steel screws. I've had no luck in finding clock hands up here, so for the time being I found a package with four thin rectangular-shaped magnets ($1) to point the degrees and align with Polaris.
Now for the inclinometer. I has hoping to find a digital one, but again, living "Up North", no luck. After going to three stores, I finally found a Mayes level and angle finder used to deterine roof slopes and grades ($11). It's magnetic and is attached to the top of the scope (I wonder if the company knows these can be used as a "telescope accessory" ).
I'll use my old Boy Scout compass to determine north and I have a very small level to check the base. Plus the Stellarium program on my laptop gives Alt/Az coordinates.
Now all I need is for these clouds to clear out so I can give the new system a trial run (of course it's cloudy, I'm also waiting on delivery of two nebula filters I've ordered)!!
Thanks again for the great post and I'm looking forward to trying this out (it looks like I may have an opening tonight).
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John
8" f/6 DBA Dob: 8X50 RACI, 2-speed Crayford
1.25": 25mm, 9mm GSO Plossls; 15mm, 20mm GSO SV;
5.7mm Antares W70; 8mm Hyperion.
2": 30mm GSO SV; 2X barlow.
Zhumell green laser light, Lumicon mount
UltraBlock, Oxygen III & DeepSky filters
"I am not the editor of a newspaper. And I shall always try to do right and be good, so that God will not make me one." - Mark Twain
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darklighteditor
Theatre King
Reged: 11/07/06
Posts: 3853
Loc: Tawas Bay, Michigan
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Here's another pic of the entire system.
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John
8" f/6 DBA Dob: 8X50 RACI, 2-speed Crayford
1.25": 25mm, 9mm GSO Plossls; 15mm, 20mm GSO SV;
5.7mm Antares W70; 8mm Hyperion.
2": 30mm GSO SV; 2X barlow.
Zhumell green laser light, Lumicon mount
UltraBlock, Oxygen III & DeepSky filters
"I am not the editor of a newspaper. And I shall always try to do right and be good, so that God will not make me one." - Mark Twain
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GordonCopestake
Carpal Tunnel
Reged: 03/02/06
Posts: 2714
Loc: Newcastle-under-Lyme, UK
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Being in the UK i plan on purchasing the lidl level for use with my system. I'm currently using a dial inclinometer but hopefully the digital one will be much more acurate
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http://www.wareforge.com
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csa/montana
Den Mother
Reged: 05/14/05
Posts: 39606
Loc: montana
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John: Congratulations! I'm so glad you found the post useful; you will be amazed at the accuracy of this simple addition.
Please let us know how your first night viewing with the $12 Push-to System works.
We better not let the inclinometer manufacturers know it's an Astronomy accessory, or the price will sky rocket!
Thanks for the kind words, also!
Carol
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Carol
AstroTech 16" Dob (Thanks ASTRONOMICS!)
Vixen 80MF/AstroTech Voyager
Masuyama's 7.5, 15, 25W, 35mm,
Pentaxes; 5XW, 7XL, 10XW.
14mm Meade 4000 UWA
TV Panoptics; 22, 35
DreamCatcher Dobservatory, #2
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kestrel0222
Carpal Tunnel
Reged: 05/21/06
Posts: 2338
Loc: Milford, Michigan
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John,
Nice job! You'll find that this system will make a BIG difference in how you find objects in the night sky. Using this system along with a good planning software package, will certainly make viewing the night sky more enjoyable. Good luck and let us know how it works for you.
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Tom
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kestrel0222
Carpal Tunnel
Reged: 05/21/06
Posts: 2338
Loc: Milford, Michigan
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Here is a pic of the dial that I made for my 12" DBA base.
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Tom
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csa/montana
Den Mother
Reged: 05/14/05
Posts: 39606
Loc: montana
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Tom: Beautiful job! How did you cut the indentation out so nicely? I also like the red on the pointer, shows up more.
Carol
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Carol
AstroTech 16" Dob (Thanks ASTRONOMICS!)
Vixen 80MF/AstroTech Voyager
Masuyama's 7.5, 15, 25W, 35mm,
Pentaxes; 5XW, 7XL, 10XW.
14mm Meade 4000 UWA
TV Panoptics; 22, 35
DreamCatcher Dobservatory, #2
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darklighteditor
Theatre King
Reged: 11/07/06
Posts: 3853
Loc: Tawas Bay, Michigan
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Tom - that looks great!
Is that a small head nail painted orange? And I agree with Carol, nice job!
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John
8" f/6 DBA Dob: 8X50 RACI, 2-speed Crayford
1.25": 25mm, 9mm GSO Plossls; 15mm, 20mm GSO SV;
5.7mm Antares W70; 8mm Hyperion.
2": 30mm GSO SV; 2X barlow.
Zhumell green laser light, Lumicon mount
UltraBlock, Oxygen III & DeepSky filters
"I am not the editor of a newspaper. And I shall always try to do right and be good, so that God will not make me one." - Mark Twain
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kestrel0222
Carpal Tunnel
Reged: 05/21/06
Posts: 2338
Loc: Milford, Michigan
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Thanks Carol and John for the kind words!
Woodworking is just one of my favorite past times, as well as astronomy. I have a second base that I got from a freind, so what I did was to cut the notch out of the side of the top board, and covered the cut surface with a piece of the "edging" from one of the spear pieces that I had. I made it look as if it was made that way from the manufacturer of the base.
Yes John, that is a small "finish" nail that I bent and placed between (2) small magnets, one on each side of the nail. They are held together with epoxy glue and finished with black and red enamal paint. It works really well. I am able to see it in the dark to adjust it as need be. I did exactly the same thing on my 8" Dob as well.
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Tom
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spudrick
member
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