rnabholz
scholastic sledgehammer
Reged: 07/25/04
Posts: 897
Loc: Iowa
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One of these magnets epoxied in the bottom of each hole would provide all the holding power necessary for this job.
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Rod Nabholz
Home Built Astronomy Projects
Wild Bird Photography
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rnabholz
scholastic sledgehammer
Reged: 07/25/04
Posts: 897
Loc: Iowa
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They would also be much quicker to place vs threading the bolt in to an insert. Here is a magnet epoxied into place.
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Rod Nabholz
Home Built Astronomy Projects
Wild Bird Photography
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rnabholz
scholastic sledgehammer
Reged: 07/25/04
Posts: 897
Loc: Iowa
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As I mentioned earlier, because of the size of the rocker, I could not just slip the scale over the rocker. It needed to be split and installed under the rocker.
Since I had extra magnets, I thought they would be a handy way to join the split circle.
I made small blocks out of maple, one to be attached to each end of the circle sectors. On one side would be 2 magnets, countersunk and epoxied in place. The mating block would have 2 wood screws with their heads left proud of the surface. Bring the two blocks together and the magnets attract the screw heads and pull them in to the magnet countersink hole. You can adjust the fit by adjusting the depth the screw is driven.
I cut the ring in half using the finest and thinnest saw I have, a mitre box back saw. I then attached the blocks to both sectors using epoxy.
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Rod Nabholz
Home Built Astronomy Projects
Wild Bird Photography
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rnabholz
scholastic sledgehammer
Reged: 07/25/04
Posts: 897
Loc: Iowa
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For the scale I used Brad C's file (thanks Brad) and had it printed by a local engineering drafting service on translucent mylar using a xerographic process. The charge was a reasonable $8. The Mylar and process makes it waterproof. After painting the ring white, I centered the scale on the ring and glued it in place with a very thin coat of Silicone, pressed during curing with appropriate astro weights
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Rod Nabholz
Home Built Astronomy Projects
Wild Bird Photography
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rnabholz
scholastic sledgehammer
Reged: 07/25/04
Posts: 897
Loc: Iowa
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When dry, I trimmed the excess with a hobby knife.
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Rod Nabholz
Home Built Astronomy Projects
Wild Bird Photography
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rnabholz
scholastic sledgehammer
Reged: 07/25/04
Posts: 897
Loc: Iowa
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When trimmed out, I have my two sections.
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Rod Nabholz
Home Built Astronomy Projects
Wild Bird Photography
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rnabholz
scholastic sledgehammer
Reged: 07/25/04
Posts: 897
Loc: Iowa
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To install them on the scope, I insert the 3 pins, the set the sectors on the pins and bring the ends together and magnets grab and close the ring.
The Ring is held in place by the heads of the pins (bolts). on one side and the side of the groundboard on the other.
To calibrate, the entire ring can rotate on the pins giving me about 60 degrees of adjustability. Once I have a known object centered I just rotate the dial to match. I am still thinking out what I want for a pointer, but I have a temporary for the time being.
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Rod Nabholz
Home Built Astronomy Projects
Wild Bird Photography
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rnabholz
scholastic sledgehammer
Reged: 07/25/04
Posts: 897
Loc: Iowa
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I am pleased at the outcome - looks pretty decent and is low hassle and easy to install.
So I now have a tracking scope with the Manual Setting Circle system - getting close to perfect..... ;^)
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Rod Nabholz
Home Built Astronomy Projects
Wild Bird Photography
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csa/montana
Wild Spirit
Reged: 05/14/05
Posts: 40118
Loc: montana
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Rod: Very Nice!! Sure looks great! Thanks for posting the steps/photos, to help out anyone else, wanting to do this setup like yours.
Again, 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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Tom Andrews
Pooh-Bah
Reged: 01/25/07
Posts: 1003
Loc: Homebase - Albuquerque, NM, cu...
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Rod,
You remain the construction guru... 
Cool stuff!
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Tom
The Secret To Life:
Focus on what you have, not on what you don't;
Focus on what you can do, not on what you can't.
************************************************
2007 Discovery 12.5" PDHQ Split-Tube Dob w/manual setting circles/Telrad/Zhummel 8x50 RACI finder scope (*For Sale*)
Coulter Odessey 8" Dob
Celestron C11-SGT
Garrett Optical 15x70 Gemini Binoculars on homemade Parallelogram w/Setting Circles
The Albuquerque Astronomy Society (TAAS)
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rnabholz
scholastic sledgehammer
Reged: 07/25/04
Posts: 897
Loc: Iowa
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Thanks Carol & Tom.
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Rod Nabholz
Home Built Astronomy Projects
Wild Bird Photography
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derekm
journeyman
Reged: 08/22/07
Posts: 7
Loc: Scarborough UK
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Hi guys,
New to the forum and just spent half a lifetime reading the whole of this thread! Sounds like a brilliant mod and I'll have to get myself into gear on my 8".
A couple of small offerings to add. First, for UK or European members, a source of Wixeys for GBP25 delivered (with EU VAT included).
http://stores.ebay.co.uk/GetItRightUK
For those of us without Palms or laptops, a free program for the desktop that will print lists of alt/az coordinates at x minute intervals for 1000s of objects.
http://casazza.net/astrohelper/
Hope someone finds them useful.
Clear skies
Derekm
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8" Skywatcher dob.Meade ETX 80. Dreaming of 16" Lightbridge!
Edited by derekm (08/23/07 03:17 AM)
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csa/montana
Wild Spirit
Reged: 05/14/05
Posts: 40118
Loc: montana
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Derekm: Thanks for the great links, they are a good addition to this thread, very, very lenthy thread 
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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derekm
journeyman
Reged: 08/22/07
Posts: 7
Loc: Scarborough UK
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Just received a "GETITRIGHT" clinometer from the link in my post above. Advertised as same as Wixey. Seems a good unit. Fast readout, quick to settle and the magnetic base sticks very well to my 8" Skywatcher tube.
One point though; the window over the LCD readout is simply a flexible film, rather than say perspex. Has anyone got the Wixey version and can say if this is the same or not? Makes no difference to the operation, but seems a bit of a cheap finish to an otherwise solid bit of gear.
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8" Skywatcher dob.Meade ETX 80. Dreaming of 16" Lightbridge!
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derekm
journeyman
Reged: 08/22/07
Posts: 7
Loc: Scarborough UK
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"First light" for the push-to system last night. Absolutely brilliant! Even using the coordinates of our club site in Astro Helper and observing from home, 15 miles away, everything was at least just inside the field of my 32mm EP. Dropped straight onto the Wild Duck Cluster (yes, I know it's hardly a difficult target) with a 3/4 moon, skyglow from the local town and a hazy sky..
After being told by the "experts", that setting circles are a waste of time (with reference to small scales on equally small EQ mounts anyway)this has been a revelation.
Total cost (in UK) $50 for clinometer and $30(!)for printing and laminating the groundboard scale - we get ripped off in Britain; it's our National pastime!
Many thanks for this brilliant thread, which for me at least, has transformed observing with a Dob. I want that 16" Lightbridge eveb more now!!!
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8" Skywatcher dob.Meade ETX 80. Dreaming of 16" Lightbridge!
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csa/montana
Wild Spirit
Reged: 05/14/05
Posts: 40118
Loc: montana
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Isn't it wonderful when the "experts" are wrong? I'm so glad you are having such great success with this system. I think, because it is so simple, many believe it simply can't work!
Thanks for your sharing of your successful venture 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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lerock
sage
Reged: 03/23/06
Posts: 311
Loc: Arizona Coast
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Carol,
You have your scope yet? Do you have pics yet. (Sorry if you allready posted, but I missed it if you did).
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Mike
18" f4.5 Obsession #1377
W/Argo Navis DSC
6" f/10 ANRA Canopus, circa 1963, modified for solar
If you don't make dust, You eat it.....
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csa/montana
Wild Spirit
Reged: 05/14/05
Posts: 40118
Loc: montana
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No, we decided against them bringing it in, until I have my Observatory completed, end of this month sometime. I really had no place to store it, & couldn't use it until the Observatory is complete.
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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lerock
sage
Reged: 03/23/06
Posts: 311
Loc: Arizona Coast
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You have way more patience than I could ever muster....
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Mike
18" f4.5 Obsession #1377
W/Argo Navis DSC
6" f/10 ANRA Canopus, circa 1963, modified for solar
If you don't make dust, You eat it.....
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greenglass
professor emeritus
Reged: 01/22/06
Posts: 540
Loc: Ontario, Canada
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Does the azimuth scale have errors if its not perfectly round and centered on the pivot and the pivot hole has some play in it?
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10" f/5 dob unf.
7x50 Tasco binos
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