Scubaguy
member
Reged: 03/05/08
Posts: 46
Loc: Mississauga, Ontario
|
|
Well, I've finally started putting together the 127 mm wide field refractor with the lens from Surplus Shed. After reading some posts in the refractor forum about collimating a refractor lens, I decided to try to make a collimatable lens system, as well as a collimatable focusser.
I put the whole thing together, and with a couple of hose clamps, mounted the scope on my SVP EQ mount.
Found Saturn with a 30 mm 2 inch eyepiece, and although small, it was very sharp. Stars had a bit of coma,( when slightly out of focus) but with a little more tweaking of the collimation, I'm confident it'll improve.
Anyway, here are some photos of what I've done so far.
Here's the collimatable lens.
--------------------
Celestron 114 GT
10 inch ATM Truss
Skywatcher 102 refractor,70 refractor
Skywatcher EQ6 with SS2K
Orion 102 mak
127mm ATM refractor
Orion 8 in f/5 newt
EQ 2,EQ 1
SkyMaster 15X70 binoculars
and a bunch of other assorted equipment
Edited by Scubaguy (05/20/08 12:24 AM)
|
Scubaguy
member
Reged: 03/05/08
Posts: 46
Loc: Mississauga, Ontario
|
|
The collimatable focusser.
--------------------
Celestron 114 GT
10 inch ATM Truss
Skywatcher 102 refractor,70 refractor
Skywatcher EQ6 with SS2K
Orion 102 mak
127mm ATM refractor
Orion 8 in f/5 newt
EQ 2,EQ 1
SkyMaster 15X70 binoculars
and a bunch of other assorted equipment
|
Scubaguy
member
Reged: 03/05/08
Posts: 46
Loc: Mississauga, Ontario
|
|
The interior of the tube.
The baffles also serve to hold the cardboard tube, which I'm going to cover with wood veneer.
--------------------
Celestron 114 GT
10 inch ATM Truss
Skywatcher 102 refractor,70 refractor
Skywatcher EQ6 with SS2K
Orion 102 mak
127mm ATM refractor
Orion 8 in f/5 newt
EQ 2,EQ 1
SkyMaster 15X70 binoculars
and a bunch of other assorted equipment
|
The bear
scholastic sledgehammer
Reged: 02/11/08
Posts: 824
Loc: rushville, indiana
|
|
this is interesting as i hope to try and build a refractor one day i will mark this as favorite and cool
doc
--------------------
Longitude -85.42786 Latitude 39.59153
"current build 6 inch F6.5 "Little Toe"
"if all else fails use duct tape "works for me"
|
Scubaguy
member
Reged: 03/05/08
Posts: 46
Loc: Mississauga, Ontario
|
|
I didn't take any pictures of the scope on the mount, but will tomorrow.
After checking out Saturn, I turned to the moon, low in the sky at about 10:30. Super sharp. Moved the 'scope a few degrees away from Luna, (which happened to be next to a very bright street light) and saw about a dozen stars, despite the glaring light just out of the field of view.
I can't wait to try this out in a dark area.
--------------------
Celestron 114 GT
10 inch ATM Truss
Skywatcher 102 refractor,70 refractor
Skywatcher EQ6 with SS2K
Orion 102 mak
127mm ATM refractor
Orion 8 in f/5 newt
EQ 2,EQ 1
SkyMaster 15X70 binoculars
and a bunch of other assorted equipment
|
Biff
Carpal Tunnel
Reged: 09/04/05
Posts: 2372
Loc: Courtice, Ontario
|
|
Which FL one is it? Hows the CA?
--------------------
Ryan
Antares 200mm f/6 Dob & 130mm f/5 Travel Dob.
Projects on the go...
- a couple 80mm SS refractors on the back burner.
- a few small mirrors awaiting polishing
- 260mm f/7.15 mirror... still polishing
Member of DRAA
 My house.
 DRAACO
|
Mirzam
super member
Reged: 04/01/08
Posts: 118
Loc: Lovettsville, VA
|
|
I've noticed that those Synta focusers can have quite a bit of sag. Did you need to do anything to address this? (I have one I need to fix if anyone has advice. Was thinking to rework the teflon bearings somehow).
|
Scubaguy
member
Reged: 03/05/08
Posts: 46
Loc: Mississauga, Ontario
|
|
Ryan, it's the 700 mm one. I've already got a 1200 mm f/l refractor, so I thought I'd try an inexpensive short f/l one. After the SS discount, and using parts I had lying around, it only cost me about $150.
I couldn't see any CA when I took it out last night, but I was really only checking for collimation and range of focus.
As for the flex in the focusser, it does seem to sag a tiny bit, when the tube is drawn all the way out. My 1200 mm scope has the same focusser, and it does sag quite a bit. I see the image move side to side when I use the electronic focus motor on it.
As for fixing it, I was thinking of perhaps adding a teflon strip to the bar located under the tensioning screw next to the finder bracket. Hopefully, this will eliminate the gap I see between it and the drawtube.
--------------------
Celestron 114 GT
10 inch ATM Truss
Skywatcher 102 refractor,70 refractor
Skywatcher EQ6 with SS2K
Orion 102 mak
127mm ATM refractor
Orion 8 in f/5 newt
EQ 2,EQ 1
SkyMaster 15X70 binoculars
and a bunch of other assorted equipment
|
Mirzam
super member
Reged: 04/01/08
Posts: 118
Loc: Lovettsville, VA
|
|
If you place a laser into the focuser you can see the focuser sag effect by the displacement of the laser spot on the objective lens. It looks like you made a nice collimatable focuser mounting adapter, but it won't help much if the sag is not addressed first.
I'm curious if anyone else has found a simple way to fix this (without buying a new focuser).
Jim
|
Chris T
super member
Reged: 01/05/05
Posts: 151
Loc: Florida
|
|
How about tapping little holes in the tube that holds the drawtube for small nylon screws. Adjust them just tight enough to keep things aligned without introducing too much friction.
--------------------
Chris Tackett
|
Steven Aggas
sage
Reged: 04/15/08
Posts: 463
Loc: Arizona
|
|
Quote:
How about tapping little holes in the tube that holds the drawtube for small nylon screws. Adjust them just tight enough to keep things aligned without introducing too much friction.
I've done this...., to my R&P focuser on a 4.5"f9 guide scope used to carry an ST-4 piggy-backed on the 20" which used a 1k square Photometrics camera. The motion of the focuser was greatly improved and I did not get a shift of the star on the ST-4 when getting it focused. It was the original cheap focuser and I would not have minded seeing four tapped holes in it if it did not work, but it was better.
Steven
--------------------
Mr. Wizard
Walking on a Dob: http://darkskyobserving.com/MtGraham.html
Elements in Harmony I, an 8"f6 German Equatorial - Stellafane Winner,
II a 20"f4.2 Newt-Dob - Astrofest Winner,
III a 6"f3.5 Finder/Newt-Dob, and
IV a 36"f4.5 Newt-Dob - "If it's up there, it's in here."
Apache-Sitgreaves Center for Astrophysics
www.DarkSkyObserving.com
|
Steven Aggas
sage
Reged: 04/15/08
Posts: 463
Loc: Arizona
|
|
Are these 127mm air-spaced achromat's anti-reflective coated? The Surplus Shed photo's don't appear so, but could be.
Also, do you guys think these 127's would make for a good 5"f5.5 binocular? Do you think there is good focal length control to do it?
--------------------
Mr. Wizard
Walking on a Dob: http://darkskyobserving.com/MtGraham.html
Elements in Harmony I, an 8"f6 German Equatorial - Stellafane Winner,
II a 20"f4.2 Newt-Dob - Astrofest Winner,
III a 6"f3.5 Finder/Newt-Dob, and
IV a 36"f4.5 Newt-Dob - "If it's up there, it's in here."
Apache-Sitgreaves Center for Astrophysics
www.DarkSkyObserving.com
|
Trondur
member
Reged: 03/09/07
Posts: 94
Loc: Cumberland County, Maine USA
|
|
Scubaguy, looks great! Can you talk about how you made the collimatable cell? I see 3 rings of plywood and a push/pull arrangement of screws.
What do the screws bear against/run through? How is the cell secured to the plywood? Which rings move, which are static?
Inquiring minds want to know. I've got an SS 80mm f11 that I haven't secured the objective in permanantly, hoping that someone would build a low-tech (read: something I could make in my limited shop) collimatable cell.
--------------------
Terry
------------------------------
Lots of Budget Glass:
60mm f11 Sears 2419 Refractor on Homemade Alt-Az Mount
80mm f11 Surplus Shed Refractor on Homemade Alt-Az Mount (Almost Done!)
100mm f6 Orion Refractor on modified Majestic mount and tripod
114mm f9 Tasco Reflector on EQ-1 mount (Apparently, a rare Tasco, because it seems OK)
7x50 Swift Swiftfocus Binoculars
Barska Blackhawk 60mm Spotting Scope on an Ambico video tripod
|
Scubaguy
member
Reged: 03/05/08
Posts: 46
Loc: Mississauga, Ontario
|
|
Hi, Terry. Unfortunately I didn't take photos of the cell as I was building it, but all I did was glue together some rings of plywood which fit around the thermoplastic cell the lens. Three 10-24 machine screws go through the plywood into the plastic to secure the lens.
Around the tube are two more rings of plywood the same OD as those of the cell. On the two mating surfaces of the two sets of rings are two rings of one eighth inch aluminum plate which are screwed onto the plywood. The aluminum was drilled and tapped to allow for the push pull collimation system.
Same thing was done for the focusser, but on a smaller scale.
The whole thing was easy to make using a router with a circle cutter, a jigsaw and some sandpaper.
I like the idea of tapping the focusser for some nylon screws to help eliminate the sag. Should be easy to do.
--------------------
Celestron 114 GT
10 inch ATM Truss
Skywatcher 102 refractor,70 refractor
Skywatcher EQ6 with SS2K
Orion 102 mak
127mm ATM refractor
Orion 8 in f/5 newt
EQ 2,EQ 1
SkyMaster 15X70 binoculars
and a bunch of other assorted equipment
|
Mirzam
super member
Reged: 04/01/08
Posts: 118
Loc: Lovettsville, VA
|
|
I also have just noticed on my Synta focuser that there are some tiny set screws on the top surface. Tightening these greatly reduced the sag. I suspect this will need to be done periodically. Don't tighten too much or the focuser will be stiff to operate.
Jim
|
Wes James
Post Laureate
Reged: 04/12/06
Posts: 3451
|
|
Quote:
Same thing was done for the focusser, but on a smaller scale.
Good idea that you made the focuser collimatable as well!
--------------------
Wes
Atlantic Beach, FL
Some bino’s from Miyauchi 5x32 Binon's up through Garrett 20x110 Signature's,
Some telescopes from a Stellarvue 80mm NHNG up through a couple of 8” reflectors…
And a wonderful 4.25" Delmarva Shiefspiegler!
Some good friends, made here on C/N.
Oh- several cats and a wonderful wife!
Anyone want a cat???? :-O
"When your work speaks for itself- Don't Interrupt" -Gamble Rogers
|
Trondur
member
Reged: 03/09/07
Posts: 94
Loc: Cumberland County, Maine USA
|
|
Thanks for the response. Did you remove the lens when you drilled the holes for the 10-24 screws? It seems like you would have, but I'm curious if you used another approach.
I'm believe that I could use your plywood construct for the cell side. I could drill and tap the 4" to 3" PVC sewer pipe reducer that I'm using at the front of the tube for the "push-pull". Not as nice as aluminum of course, but not a 127mm either.
--------------------
Terry
------------------------------
Lots of Budget Glass:
60mm f11 Sears 2419 Refractor on Homemade Alt-Az Mount
80mm f11 Surplus Shed Refractor on Homemade Alt-Az Mount (Almost Done!)
100mm f6 Orion Refractor on modified Majestic mount and tripod
114mm f9 Tasco Reflector on EQ-1 mount (Apparently, a rare Tasco, because it seems OK)
7x50 Swift Swiftfocus Binoculars
Barska Blackhawk 60mm Spotting Scope on an Ambico video tripod
|
Scubaguy
member
Reged: 03/05/08
Posts: 46
Loc: Mississauga, Ontario
|
|
No, I didn't have to remove the lens at all.
There were already three holes in the plastic, and it was a simple enough matter to tap them. The only hard part was drilling through the plywood in exactly the right place.
--------------------
Celestron 114 GT
10 inch ATM Truss
Skywatcher 102 refractor,70 refractor
Skywatcher EQ6 with SS2K
Orion 102 mak
127mm ATM refractor
Orion 8 in f/5 newt
EQ 2,EQ 1
SkyMaster 15X70 binoculars
and a bunch of other assorted equipment
|
Happy-Idiot
Carpal Tunnel
Reged: 04/06/06
Posts: 2801
Loc: 3rd Rock
|
|
Great job! What material did you use for the baffles and how did you cut them? I also have a 127mm SS lens and cell, i am using an aluminum tube, neither focuser or cell will be collimatable, not as nice as yours. Keep up the good work!
--------------------
Brian
A small scope that gets used often is a better investment than a big scope that stays in the closet.
Unitrons, you spend more time looking at them than you do through them.
|
Preston Smith
Military Observer
Reged: 04/24/05
Posts: 3435
Loc: Eureka, Pa
|
|
Scubaguy - Great setup! Go for it!
Scubaguy and Brian: I am on backorder for one of these objectives but I'm running out of time (my other projects are soaking up my astro bucks). I'm debating on canceling the order. Have either of you done a full star test yet? Any astigmatism?
Thanks!
--------------------
Preston
Lift your eyes and look to the heavens: Who created all these? He who brings out the starry host one by one, and calls them each by name. Because of His great power and mighty strength, not one of them is missing. Isaiah 40:26
SV115T,NHII,SV70,SV50 and Tele Vue Ranger
Vintage Refractors: Asahi-Pentax, Edmund Scientific, Tasco, Unitron
60mm Telescope Club
Edited by Preston Smith (05/26/08 02:20 PM)
|
Happy-Idiot
Carpal Tunnel
Reged: 04/06/06
Posts: 2801
Loc: 3rd Rock
|
|
i bought the lens/lens cell, tube, focuser plate, but need to buy the focuser. I too am running low on green(too many Unitron buys)so i am sorry no star test yet, its still in the box.
--------------------
Brian
A small scope that gets used often is a better investment than a big scope that stays in the closet.
Unitrons, you spend more time looking at them than you do through them.
|
Scubaguy
member
Reged: 03/05/08
Posts: 46
Loc: Mississauga, Ontario
|
|
Finally found the time to take some pictures of the completed telescope.
I had thought of covering the tube in oak veneer, but that didn't work out too well, so I decided to paint it white.
Five or six coats of Krylon gloss white later, it's done.
The dew shield is made of a larger diameter sonotube also painted white. Two large hose clamps over some flexible black plastice serve as rings.
Mount the whole thing on my SVP mount and there you go.
Here are some photo's.
--------------------
Celestron 114 GT
10 inch ATM Truss
Skywatcher 102 refractor,70 refractor
Skywatcher EQ6 with SS2K
Orion 102 mak
127mm ATM refractor
Orion 8 in f/5 newt
EQ 2,EQ 1
SkyMaster 15X70 binoculars
and a bunch of other assorted equipment
|
Scubaguy
member
Reged: 03/05/08
Posts: 46
Loc: Mississauga, Ontario
|
|
Another...
--------------------
Celestron 114 GT
10 inch ATM Truss
Skywatcher 102 refractor,70 refractor
Skywatcher EQ6 with SS2K
Orion 102 mak
127mm ATM refractor
Orion 8 in f/5 newt
EQ 2,EQ 1
SkyMaster 15X70 binoculars
and a bunch of other assorted equipment
|
Scubaguy
member
Reged: 03/05/08
Posts: 46
Loc: Mississauga, Ontario
|
|
One more.
--------------------
Celestron 114 GT
10 inch ATM Truss
Skywatcher 102 refractor,70 refractor
Skywatcher EQ6 with SS2K
Orion 102 mak
127mm ATM refractor
Orion 8 in f/5 newt
EQ 2,EQ 1
SkyMaster 15X70 binoculars
and a bunch of other assorted equipment
|
Scubaguy
member
Reged: 03/05/08
Posts: 46
Loc: Mississauga, Ontario
|
|
A picture of the moon, afocal.
--------------------
Celestron 114 GT
10 inch ATM Truss
Skywatcher 102 refractor,70 refractor
Skywatcher EQ6 with SS2K
Orion 102 mak
127mm ATM refractor
Orion 8 in f/5 newt
EQ 2,EQ 1
SkyMaster 15X70 binoculars
and a bunch of other assorted equipment
|
Scubaguy
member
Reged: 03/05/08
Posts: 46
Loc: Mississauga, Ontario
|
|
Prime focus, not quite focussed, 'though. It's my first try.
--------------------
Celestron 114 GT
10 inch ATM Truss
Skywatcher 102 refractor,70 refractor
Skywatcher EQ6 with SS2K
Orion 102 mak
127mm ATM refractor
Orion 8 in f/5 newt
EQ 2,EQ 1
SkyMaster 15X70 binoculars
and a bunch of other assorted equipment
|
Happy-Idiot
Carpal Tunnel
Reged: 04/06/06
Posts: 2801
Loc: 3rd Rock
|
|
Nice work Scuba!  I just received some carbon fiber for a dewshield and i was thinking of starting the project within the next week or so, but i still have a kayak to finish and other rehab scope projects. But your scope is a motivation. Great job!
--------------------
Brian
A small scope that gets used often is a better investment than a big scope that stays in the closet.
Unitrons, you spend more time looking at them than you do through them.
|
photonovore
Moonatic
Reged: 12/24/04
Posts: 2502
Loc: tacoma wa
|
|
Very nice job! I take it the dew shield retracts? It appears as though it is not fully extended in the pix...is that correct or?
--------------------
Mardi
4" achromat, ETX-70.
Whitepeak Lunar Observatory Website
|
Scubaguy
member
Reged: 03/05/08
Posts: 46
Loc: Mississauga, Ontario
|
|
It does retract, but it only goes out about an inch in front of the lens. Any longer and I don't think it would look right. What I tried is to put a piece of thin plastic tube I had around the lens cell. That's what is sticking out the front. It just slips on and off.
--------------------
Celestron 114 GT
10 inch ATM Truss
Skywatcher 102 refractor,70 refractor
Skywatcher EQ6 with SS2K
Orion 102 mak
127mm ATM refractor
Orion 8 in f/5 newt
EQ 2,EQ 1
SkyMaster 15X70 binoculars
and a bunch of other assorted equipment
|
Steven Aggas
sage
Reged: 04/15/08
Posts: 463
Loc: Arizona
|
|
Are these 127mm air-spaced achromat's anti-reflective coated? The Surplus Shed photo's don't appear so, but could be.
Also, do you guys think these 127's would make for a good 5"f5.5 binocular? Do you think there is good focal length control to do it?
Thanks, Steven
--------------------
Mr. Wizard
Walking on a Dob: http://darkskyobserving.com/MtGraham.html
Elements in Harmony I, an 8"f6 German Equatorial - Stellafane Winner,
II a 20"f4.2 Newt-Dob - Astrofest Winner,
III a 6"f3.5 Finder/Newt-Dob, and
IV a 36"f4.5 Newt-Dob - "If it's up there, it's in here."
Apache-Sitgreaves Center for Astrophysics
www.DarkSkyObserving.com
|
GlennLeDrew
Pooh-Bah
Reged: 06/18/08
Posts: 1250
Loc: Ottawa, Ontario, Canada
|
|
Quote:
It does retract, but it only goes out about an inch in front of the lens. Any longer and I don't think it would look right. What I tried is to put a piece of thin plastic tube I had around the lens cell. That's what is sticking out the front. It just slips on and off.
If it protrudes only about an it might as well not be there. For reasonable dew prevention (delay, actually) a dew shield for a 5" ought to extend at least 7-8". And if it's a significantly larger I.D. tube than the clear aperture, the even a bit more extension is good.
What looks to possibly be more of a problem is the *very* long focuser tube for the focal ratio. Based on the pix, I wouldn't be at all surprised if the inner end of the focuser tube is acting as an aperture-restricting baffle. You might want to check this out...
============
Steve,
I was looking at the SS web site checking out these lenses, and I did get the impression that they've at least got a basic mag fluoride coating. Hard to tell on how many surfaces, though.
--------------------
Home-made 11X50 right angle bino, 8.1 deg. FOV
Modified 26X100 bino, 3.5 deg. FOV
Home-made Mk II RA bino, using interchangeable objectives and eyepieces
My Gallery
Mediocre minds discuss people. Good minds discuss events. Great minds discuss ideas.
|
Mike Lynch
member
Reged: 04/07/06
Posts: 52
|
|
I am hoping Surplus Shed will get these lenses back in stock soon, as I want to build this same scope. I'm looking at that same stock Synta focuser as well. So I searched the forums and found this thread!
May I ask how long the tubing needs to be for this scope to be able to focus a variety of eyepieces while not reducing the light-path coming to the focuser?
Thanks,
Mike
|
Scubaguy
member
Reged: 03/05/08
Posts: 46
Loc: Mississauga, Ontario
|
|
I've actually rebuilt this 'scope since I last posted.
The focusser was cutting into the light cone, so I removed 3 inches of the drawtube. The length now is 18 inches, from the front of the lens cell to the rear of the tube, where the focusser attaches. I determined this by trying various eyepieces and also my Nikon at prime focus. I found I only needed to move the drawtube about an inch between the two extremes of focus for my camera and eyepieces, which is why I shortened the drawtube.
--------------------
Celestron 114 GT
10 inch ATM Truss
Skywatcher 102 refractor,70 refractor
Skywatcher EQ6 with SS2K
Orion 102 mak
127mm ATM refractor
Orion 8 in f/5 newt
EQ 2,EQ 1
SkyMaster 15X70 binoculars
and a bunch of other assorted equipment
|
Lynnrb
member
Reged: 01/01/08
Posts: 54
Loc: Phoenix, Az
|
|
Here is my version of the S/S 127 f/5.5 . I used a 2.7" focuser to prevent vignetting. Can just fit the entire Veil Nebula in the field of the 35mm Panoptic.
Edited by Lynnrb (01/05/09 10:51 PM)
|
dawsonian2000
professor emeritus
Reged: 07/26/06
Posts: 552
Loc: Riverview, FL, USA
|
|
Mike,
SurplusShed just last week had a restock run of the 127mm objectives (1200mm and 700mm FL). I added my email account to the notification list via the "Notify Me" button nearly a year (I hate to say) before I receive a message stating they had some in stock. I jumped on it immediately. I purchased one of the 127mm f/9.4 objectives. In less than a week, all of the 127mm lenses were gone! My friend called SurplusShed and they said they should have another shipment in about a month. So I encourage you to get on the notification list and be ready to ponce on one quick-fast-and in a hurry.
Mel
--------------------
Clear Skies, Forever!
The Vega Sky Center
10" (254mm) F/5.65 Home Built Fork Mounted Newtonian Reflector
5" (127mm) F/9.4 Home Built Refractor (under construction)
3.5" (90mm) F/11.1 "Vixen-Spec Modified" Konus Refractor
3.1" (80mm) F/6 Scopos ED APO Refractor
4.5" (114mm) F/8 Tasco 11te-5 Newtonian (under restoration)
2.4" (60mm) F/16.7 Tasco 7te-5 Refractor
2.4" (60mm) F/15 Jason Discoverer 313 Refractor
http://www.vega-sky-center.com
|
dawsonian2000
professor emeritus
Reged: 07/26/06
Posts: 552
Loc: Riverview, FL, USA
|
|
Hey Lynnrb!
What I nice 5" you have there! Did you build this one yourself using a S/S objective? Or, is this a manufactured model with similar optics (OD and FL)? If you built it yourself, where did you get your objective cell and tube from? I will be building a S/S 127mm f/9.4 and would like to replace the plastic cell with a metal collimatible model. I have seen the cells on Island Eyepiece and Telescopes website, but they are the screw on type. I need one like yours, which bolts to the tube. Speaking of tube (I prefer seamless aluminum), depending on the type of cell I use, I will need one to match the inside diameter of the cell. So any insight you, or any one else in the group can provide would be greatly appreciated.
Mel
--------------------
Clear Skies, Forever!
The Vega Sky Center
10" (254mm) F/5.65 Home Built Fork Mounted Newtonian Reflector
5" (127mm) F/9.4 Home Built Refractor (under construction)
3.5" (90mm) F/11.1 "Vixen-Spec Modified" Konus Refractor
3.1" (80mm) F/6 Scopos ED APO Refractor
4.5" (114mm) F/8 Tasco 11te-5 Newtonian (under restoration)
2.4" (60mm) F/16.7 Tasco 7te-5 Refractor
2.4" (60mm) F/15 Jason Discoverer 313 Refractor
http://www.vega-sky-center.com
|
stars_in_my_eyes
scholastic sledgehammer
Reged: 03/24/08
Posts: 803
|
|
Nice job.
Could you go into detail as to WHERE you get your parts...all of them?
Sourcing for parts seems to be a major hassle for building a scope.
Thanks
|
Lynnrb
member
Reged: 01/01/08
Posts: 54
Loc: Phoenix, Az
|
|
I made this scope from salvaged parts. The lens and cell from Surplus Shed. The 2.7" focuser is from a Meade ED refractor, the original Meade ED in the 90's. The tube and dew shield from a scope with a defective lens, had to shorten the tube. It took a little machining to get all the parts to fit. The alt/az mount is a gem coverted to operate as alt/az. This scope could not have been built with a 2" focuser because of the vignetting problem. Now the outside edge of the lens is just visible from the eyepiece position. Lynn
Edited by Lynnrb (01/08/09 08:57 PM)
|
Scott Horstman
Vendor- Backyard Observatories
Reged: 03/11/04
Posts: 8074
|
|
Nice work guys. Impressive looking scopes. Y'all got me watchin stuff at Surplus Shed now. 
--------------------
|
dawsonian2000
professor emeritus
Reged: 07/26/06
Posts: 552
Loc: Riverview, FL, USA
|
|
Thanks for the information on your telescope, Lynn. It just so happens that I received my 127mm f/9.4 objective from Surplus Shed today! Understanding now that you built your instrument using salvaged components, I will have to make due with my initial plans to purchase raw items. If there is one thing I'd like to get that your telescope has, it would be the objective cell. The one that came with the lens I bought is made from thermo-plastic and is uncollimatible. As I pointed out earlier, Island Eyepiece and Telescopes has cells that collimate, but they are of the screw-on variety. I will call IET again to verify. BTW - What is the outside diameter of your tube?
As for the focuser, I believe I can go with a 2" GSO 10:1 Dual Speed Crayford refractor focuser. I just have to make an adapter to attach it to the tube. I have found several companies that sell these adapters along with the focusers. Unfortunately, the adapter has an inside diameter of 130mm, and with a 127mm OD tube it would require shimming of some sort. That's provided of course I use the cell that came with the objective. I am also considering building a collimatible cell similar to the one Scubaguy constructed.
Once again, your scope is awesome! Should you have any addition insight, please pass it on to the group.
Scubaguy!... Awesome craftsmanship as well! I know I will be assimilating a wealth of knowledge from you 127mm telescope project as well.
--------------------
Clear Skies, Forever!
The Vega Sky Center
10" (254mm) F/5.65 Home Built Fork Mounted Newtonian Reflector
5" (127mm) F/9.4 Home Built Refractor (under construction)
3.5" (90mm) F/11.1 "Vixen-Spec Modified" Konus Refractor
3.1" (80mm) F/6 Scopos ED APO Refractor
4.5" (114mm) F/8 Tasco 11te-5 Newtonian (under restoration)
2.4" (60mm) F/16.7 Tasco 7te-5 Refractor
2.4" (60mm) F/15 Jason Discoverer 313 Refractor
http://www.vega-sky-center.com
|
dawsonian2000
professor emeritus
Reged: 07/26/06
Posts: 552
Loc: Riverview, FL, USA
|
|
Hey Scott,
There are some great deals at Surplus Shed. But, I generally check out reviews on the items I am interested in before making a purchase. I just hope the 127mm f/9.4 objective I purchased from them is a winner.
--------------------
Clear Skies, Forever!
The Vega Sky Center
10" (254mm) F/5.65 Home Built Fork Mounted Newtonian Reflector
5" (127mm) F/9.4 Home Built Refractor (under construction)
3.5" (90mm) F/11.1 "Vixen-Spec Modified" Konus Refractor
3.1" (80mm) F/6 Scopos ED APO Refractor
4.5" (114mm) F/8 Tasco 11te-5 Newtonian (under restoration)
2.4" (60mm) F/16.7 Tasco 7te-5 Refractor
2.4" (60mm) F/15 Jason Discoverer 313 Refractor
http://www.vega-sky-center.com
|
allanovercast
member
Reged: 08/02/07
Posts: 55
Loc: Billings, MT
|
|
I also received my 127mm/1200mm lens and just received the aluminum tubing I will be using. I purchased 5"OD, 4.5"ID tubing and based on my Solidworks modeling I need to remove a small amount of the tubing at the lens side. I have not cut the tubing yet, trying to figure out the best length for multiple eye pieces. Also what material was used for the baffles? I got the tubing from NDUSTRIAL METAL SALES, LLC for ~$125 dollars including shipping (48" piece). My focuser is from Scope Stuff and is an Antares dual speed model. An adapter ring was needed and I am still waiting on that to arrive.
So how long did you make your tube and what baffle material did you use?
Thanks,
Allan in Billings MT
--------------------
Allan Overcast
Cloudy Skies Observatory
10" Meade RCX-400
80mm Homeade Refractor
1277mm Homeade Refractor
Canon 350D Modified Camera
Q-Guider Camera
Pier-Tech 2 Pier
8' Exploradome
http://www.cloudyskies.org
|
allanovercast
member
Reged: 08/02/07
Posts: 55
Loc: Billings, MT
|
|
You can download the Solidworks Model, free viewer and .jpg of the project from my web site:
http://www.cloudyskies.org/6.html
I plan on making the tube 41.5" long.
Allan in Billings
--------------------
Allan Overcast
Cloudy Skies Observatory
10" Meade RCX-400
80mm Homeade Refractor
1277mm Homeade Refractor
Canon 350D Modified Camera
Q-Guider Camera
Pier-Tech 2 Pier
8' Exploradome
http://www.cloudyskies.org
|
dawsonian2000
professor emeritus
Reged: 07/26/06
Posts: 552
Loc: Riverview, FL, USA
|
|
Congrats on getting one of the 127mm f/9.4 objectives from SS, Allan! Their supply surely did not last long.
Of recent, I too received my main tube. I purchased a 5" OD x 48" L x .078" WT (main tube) and a 6" OD x 12" x .083" WT section of tubing for my dew shield from Hastings. Hit me up for about $100.00 for both pieces. Currently, I am gathering all of the components before going forward.
My focuser will be from an old Meade 127ED refractor. I just have to make an adapter to attach it to the main tube. The flange for this R&P focuser is an eight of an inch narrower in inside diameter than the 5" tube I have.
BTW - Are you planning on using the objective cell that came with your lens? If not, please let me know your alternate plans.
I look forward to reading your updates as well as posting mine here in this forum.
Later,
--------------------
Clear Skies, Forever!
The Vega Sky Center
10" (254mm) F/5.65 Home Built Fork Mounted Newtonian Reflector
5" (127mm) F/9.4 Home Built Refractor (under construction)
3.5" (90mm) F/11.1 "Vixen-Spec Modified" Konus Refractor
3.1" (80mm) F/6 Scopos ED APO Refractor
4.5" (114mm) F/8 Tasco 11te-5 Newtonian (under restoration)
2.4" (60mm) F/16.7 Tasco 7te-5 Refractor
2.4" (60mm) F/15 Jason Discoverer 313 Refractor
http://www.vega-sky-center.com
|
dawsonian2000
professor emeritus
Reged: 07/26/06
Posts: 552
Loc: Riverview, FL, USA
|
|
Hey Allan,
Nice website! I will add your website to the links on mine. Perhaps under "The VSC's Favorite Amateur Astronmer Websites" drop-down.
Look forward to seeing more of your telscope updates. I will keep everyone posted on mine as well.
--------------------
Clear Skies, Forever!
The Vega Sky Center
10" (254mm) F/5.65 Home Built Fork Mounted Newtonian Reflector
5" (127mm) F/9.4 Home Built Refractor (under construction)
3.5" (90mm) F/11.1 "Vixen-Spec Modified" Konus Refractor
3.1" (80mm) F/6 Scopos ED APO Refractor
4.5" (114mm) F/8 Tasco 11te-5 Newtonian (under restoration)
2.4" (60mm) F/16.7 Tasco 7te-5 Refractor
2.4" (60mm) F/15 Jason Discoverer 313 Refractor
http://www.vega-sky-center.com
|
allanovercast
member
Reged: 08/02/07
Posts: 55
Loc: Billings, MT
|
|
Initially I will be using the objective cell, but am looking into either designing myself a new collimatable version or locating one that is already made. I am a bit concerned that the plastic one will not be as stable as I would like.
My focuser adapter ring came in yesterday but have not had much time to play with it. I just finished building a new house, shop and new observatory platform for the dome. Way hoping to get the dome placed yesterday before a really cold storm arrived, but no such luck. So hopefully tomorrow I will have some time to veryify fit. From my initial estimates, the focuser is 0.078" to small so I will need some type of washer to snug it all up.
I will keep posting the progress.
Allan Overcast
Cloudy Skies Observatory
10" Meade RCX-400
80mm Homeade Refractor
Canon 350D Modified Camera
Pier-Tech 2 Pier
8' Exploradome
http://www.cloudyskies.org
--------------------
Allan Overcast
Cloudy Skies Observatory
10" Meade RCX-400
80mm Homeade Refractor
1277mm Homeade Refractor
Canon 350D Modified Camera
Q-Guider Camera
Pier-Tech 2 Pier
8' Exploradome
http://www.cloudyskies.org
|
StarryHost
newbie
Reged: 01/13/09
Posts: 1
|
|
What are the star images like on these lenses? I'd like to get either of the 127mm objectives from Surplus Shed but I am worried about how pin point the images are over the field of view.
Thanks,
Jack Swaton
StarryHost.com
|
allanovercast
member
Reged: 08/02/07
Posts: 55
Loc: Billings, MT
|
|
Initially they look good, but I don't have mine completely built. When I have mine built I will post the pictures. I do plan on a 2" fringe filter to block some of the CA that I expect with an achromatic lens.
Allan
--------------------
Allan Overcast
Cloudy Skies Observatory
10" Meade RCX-400
80mm Homeade Refractor
1277mm Homeade Refractor
Canon 350D Modified Camera
Q-Guider Camera
Pier-Tech 2 Pier
8' Exploradome
http://www.cloudyskies.org
|
beanz4
member
Reged: 08/23/08
Posts: 33
|
|
Here is my version of the Surplus Shed 127mm refractor. It is not completely finished yet, just wanted to get it together so I can test it out while the weather is cooperating.
|
beanz4
member
Reged: 08/23/08
Posts: 33
|
|
A quick terrestrial pic taken just for fun, about 1/4 mile away. Will try to take some pic tonight, if mother nature is kind.
|
beanz4
member
Reged: 08/23/08
Posts: 33
|
|
srry here is the image
|
beanz4
member
Reged: 08/23/08
Posts: 33
|
|
sorry again
|
dawsonian2000
professor emeritus
Reged: 07/26/06
Posts: 552
Loc: Riverview, FL, USA
|
|
So, where did you purchase your focuser adapter and what type and model of focus will you be using? As for a collimatable objective cell, I have seen them sold by Island Eyepiece and Telescope. But, I believe they are the type that screws onto your main tube. I could be wrong. I plan to use the original plastic cell for the moment as well. I will consult with IE&T to verify the construction design of their cells.
Hope your dome project went successfully.
--------------------
Clear Skies, Forever!
The Vega Sky Center
10" (254mm) F/5.65 Home Built Fork Mounted Newtonian Reflector
5" (127mm) F/9.4 Home Built Refractor (under construction)
3.5" (90mm) F/11.1 "Vixen-Spec Modified" Konus Refractor
3.1" (80mm) F/6 Scopos ED APO Refractor
4.5" (114mm) F/8 Tasco 11te-5 Newtonian (under restoration)
2.4" (60mm) F/16.7 Tasco 7te-5 Refractor
2.4" (60mm) F/15 Jason Discoverer 313 Refractor
http://www.vega-sky-center.com
|
dawsonian2000
professor emeritus
Reged: 07/26/06
Posts: 552
Loc: Riverview, FL, USA
|
|
Not a bad image, beanz4! Little to no CA in the terrestrial photo. I hope this is indicative of the 1200mm model. Look forward to seeing your completed instrument.
--------------------
Clear Skies, Forever!
The Vega Sky Center
10" (254mm) F/5.65 Home Built Fork Mounted Newtonian Reflector
5" (127mm) F/9.4 Home Built Refractor (under construction)
3.5" (90mm) F/11.1 "Vixen-Spec Modified" Konus Refractor
3.1" (80mm) F/6 Scopos ED APO Refractor
4.5" (114mm) F/8 Tasco 11te-5 Newtonian (under restoration)
2.4" (60mm) F/16.7 Tasco 7te-5 Refractor
2.4" (60mm) F/15 Jason Discoverer 313 Refractor
http://www.vega-sky-center.com
|
dawsonian2000
professor emeritus
Reged: 07/26/06
Posts: 552
Loc: Riverview, FL, USA
|
|
Same as Allan, Jack. I have not tested my optics yet. I am still hashing out preliminary designs. I will start assembly sometime in February and hope to have a report on the image quality during that time. As with the construction overview of my 10" f/5.6 Newt project, I plan to cover the 127mm f/9.4 refractor similarly on my astronomical webhub.
--------------------
Clear Skies, Forever!
The Vega Sky Center
10" (254mm) F/5.65 Home Built Fork Mounted Newtonian Reflector
5" (127mm) F/9.4 Home Built Refractor (under construction)
3.5" (90mm) F/11.1 "Vixen-Spec Modified" Konus Refractor
3.1" (80mm) F/6 Scopos ED APO Refractor
4.5" (114mm) F/8 Tasco 11te-5 Newtonian (under restoration)
2.4" (60mm) F/16.7 Tasco 7te-5 Refractor
2.4" (60mm) F/15 Jason Discoverer 313 Refractor
http://www.vega-sky-center.com
|
allanovercast
member
Reged: 08/02/07
Posts: 55
Loc: Billings, MT
|
|
The focuser was purchased from Scopestuff (.com) and is an Antares model Crayford dual speed model. It's designed for 3.4" tubes. They also sell an adapter ring that upsizes the diameter to 4.40"ID tubes. My tube has an ID of 4.50" but the powder coating and small shims will eat up the additional 0.100" difference. I verified that it will fit, and it does, so on to the next step, cutting the tube.
Allan Overcast
Cloudy Skies Observatory
45.783°N
108.500°W
Meade 10" RCX400
5" Refractor
Meade DSI-Pro
Canon 350D modified
--------------------
Allan Overcast
Cloudy Skies Observatory
10" Meade RCX-400
80mm Homeade Refractor
1277mm Homeade Refractor
Canon 350D Modified Camera
Q-Guider Camera
Pier-Tech 2 Pier
8' Exploradome
http://www.cloudyskies.org
|
allanovercast
member
Reged: 08/02/07
Posts: 55
Loc: Billings, MT
|
|
I also put in a request to Island Eyepiece and telescope yesterday for any type of mechanical drawing for the lens cell. When I hear back from them I am hoping to 3D model the cell and make sure it will fit the tubes ID that I have. I am reluctant to order one until I have that information.
Allan Overcast
Cloudy Skies Observatory
45.783°N
108.500°W
Meade 10" RCX400
5" Refractor
Meade DSI-Pro
Canon 350D modified
--------------------
Allan Overcast
Cloudy Skies Observatory
10" Meade RCX-400
80mm Homeade Refractor
1277mm Homeade Refractor
Canon 350D Modified Camera
Q-Guider Camera
Pier-Tech 2 Pier
8' Exploradome
http://www.cloudyskies.org
|
stars_in_my_eyes
scholastic sledgehammer
Reged: 03/24/08
Posts: 803
|
|
Quote:
The focuser was purchased from Scopestuff (.com) and is an Antares model Crayford dual speed model. It's designed for 3.4" tubes. They also sell an adapter ring that upsizes the diameter to 4.40"ID tubes. My tube has an ID of 4.50" but the powder coating and small shims will eat up the additional 0.100" difference. I verified that it will fit, and it does, so on to the next step, cutting the tube.
Allan Overcast
Cloudy Skies Observatory
45.783°N
108.500°W
Meade 10" RCX400
5" Refractor
Meade DSI-Pro
Canon 350D modified
Where did you get the tube?
Thanks
|
dawsonian2000
professor emeritus
Reged: 07/26/06
Posts: 552
Loc: Riverview, FL, USA
|
|
Hey stars_in_my_eyes,
I got my tube from Hastings Irrigation Pipe Company. It is 5.0" OD x 48" L x 0.78" Wall Thickness. Fits the original cell perfectly. Cost me about $58.00.
--------------------
Clear Skies, Forever!
The Vega Sky Center
10" (254mm) F/5.65 Home Built Fork Mounted Newtonian Reflector
5" (127mm) F/9.4 Home Built Refractor (under construction)
3.5" (90mm) F/11.1 "Vixen-Spec Modified" Konus Refractor
3.1" (80mm) F/6 Scopos ED APO Refractor
4.5" (114mm) F/8 Tasco 11te-5 Newtonian (under restoration)
2.4" (60mm) F/16.7 Tasco 7te-5 Refractor
2.4" (60mm) F/15 Jason Discoverer 313 Refractor
http://www.vega-sky-center.com
|
dawsonian2000
professor emeritus
Reged: 07/26/06
Posts: 552
Loc: Riverview, FL, USA
|
|
Thanks for the reply, Allan! Please let me know when you receive a copy of the mechanical drawing of the cell (if they will provide you with it). I am sure it would prove helpful when I decide to go with a collimatable cell myself.
--------------------
Clear Skies, Forever!
The Vega Sky Center
10" (254mm) F/5.65 Home Built Fork Mounted Newtonian Reflector
5" (127mm) F/9.4 Home Built Refractor (under construction)
3.5" (90mm) F/11.1 "Vixen-Spec Modified" Konus Refractor
3.1" (80mm) F/6 Scopos ED APO Refractor
4.5" (114mm) F/8 Tasco 11te-5 Newtonian (under restoration)
2.4" (60mm) F/16.7 Tasco 7te-5 Refractor
2.4" (60mm) F/15 Jason Discoverer 313 Refractor
http://www.vega-sky-center.com
|
dawsonian2000
professor emeritus
Reged: 07/26/06
Posts: 552
Loc: Riverview, FL, USA
|
|
Allan,
Have you considered using the GSO model J120 130mm focuser adapter (sold at Agena AstroProducts) as an option? The 3.4 Crayford you have would fit on it perfectly. Also, being that the inside diameter of this focuser adapter bushing is 130mm and you unfinished tube is 127mm, it may fit quite well on it after it is powder-coated. Depending on how thick the powder-coating is. You can find them via this link: http://www.agenaastro.com/Antares-Crayford-Adapter-Plate-Bushing-Meade-p/paf-an-jca.htm
--------------------
Clear Skies, Forever!
The Vega Sky Center
10" (254mm) F/5.65 Home Built Fork Mounted Newtonian Reflector
5" (127mm) F/9.4 Home Built Refractor (under construction)
3.5" (90mm) F/11.1 "Vixen-Spec Modified" Konus Refractor
3.1" (80mm) F/6 Scopos ED APO Refractor
4.5" (114mm) F/8 Tasco 11te-5 Newtonian (under restoration)
2.4" (60mm) F/16.7 Tasco 7te-5 Refractor
2.4" (60mm) F/15 Jason Discoverer 313 Refractor
http://www.vega-sky-center.com
|
allanovercast
member
Reged: 08/02/07
Posts: 55
Loc: Billings, MT
|
|
I purchased my tube from Industrial Metal Sales
http://www.industrialmetalsales.com/Aluminum_Round_Tube.html
I chose the 1/4 wall thickness to perfectly support the lens assembly. It fits perfectly, no flop at all. I have little to no room even for paint, so I will have to tape off the inside of the tube when I paint it. The other reason for the tick outside was the need to match focuser to the inside of the tube. 20-20 an irrigation tube with a tiny bit more space would be nice. Weight wise, the tube is 17 pounds, 3 pounds for the lens and 3 pounds for the focuser. The finder scope, Stellarvue F50M and rings should be 4 pounds. So I expect the scope when finished to weight in at ~27 pounds. I have an LXD55 mount I will initially use, but want to see if I can mount it to my 10" RCX400, but will see.
Allan Overcast
Cloudy Skies Observatory
10" Meade RCX-400
80mm Homeade Refractor
Canon 350D Modified Camera
Pier-Tech 2 Pier
8' Exploradome
http://www.cloudyskies.org
--------------------
Allan Overcast
Cloudy Skies Observatory
10" Meade RCX-400
80mm Homeade Refractor
1277mm Homeade Refractor
Canon 350D Modified Camera
Q-Guider Camera
Pier-Tech 2 Pier
8' Exploradome
http://www.cloudyskies.org
|
allanovercast
member
Reged: 08/02/07
Posts: 55
Loc: Billings, MT
|
|
I purchased my tube from Industrial Metal Sales
http://www.industrialmetalsales.com/Aluminum_Round_Tube.html
I selected the 1/4 wall thickness to perfectly support the lens assembly. It fits perfectly, no flop at all. I have little to no room even for paint, so I will have to tape off the inside of the tube when I paint it. The other reason for the thick outside was the need to match focuser to the inside of the tube. 20-20 an irrigation tube with a tiny bit more space would be nice. Weight wise, the tube is 17 pounds, 3 pounds for the lens and 3 pounds for the focuser. The finder scope, Stellarvue F50M and rings should be 4 pounds. So I expect the scope when finished to weight in at ~27 pounds. I have an LXD55 mount I will initially use, but want to see if I can mount it to my 10" RCX400, but will see.
Allan Overcast
Cloudy Skies Observatory
10" Meade RCX-400
80mm Homeade Refractor
Canon 350D Modified Camera
Pier-Tech 2 Pier
8' Exploradome
http://www.cloudyskies.org
--------------------
Allan Overcast
Cloudy Skies Observatory
10" Meade RCX-400
80mm Homeade Refractor
1277mm Homeade Refractor
Canon 350D Modified Camera
Q-Guider Camera
Pier-Tech 2 Pier
8' Exploradome
http://www.cloudyskies.org
|
allanovercast
member
Reged: 08/02/07
Posts: 55
Loc: Billings, MT
|
|
Hmmm, interesting and it will fit outside the tube. I will check into this. It would help stablize the focuser and would look much better.
Thanks!
Allan Overcast
Cloudy Skies Observatory
10" Meade RCX-400
80mm Homeade Refractor
Canon 350D Modified Camera
Pier-Tech 2 Pier
8' Exploradome
http://www.cloudyskies.org
--------------------
Allan Overcast
Cloudy Skies Observatory
10" Meade RCX-400
80mm Homeade Refractor
1277mm Homeade Refractor
Canon 350D Modified Camera
Q-Guider Camera
Pier-Tech 2 Pier
8' Exploradome
http://www.cloudyskies.org
|
allanovercast
member
Reged: 08/02/07
Posts: 55
Loc: Billings, MT
|
|
I just got an email reply from Island Optics:
>>>>> Quote
I can no longer get the 127ALC
I may be able to get 120mm cell that could be machined out to fit a 127mm lens (machining done by supplier)
Costs would be $80 Cdn
Sorry we have no detailed info on these
Thanks
Brian
Island Eyepiece and Telescope Ltd
107-2690 Mill Bay Rd
Mill Bay, BC
V0R 2P0
www.islandeyepiece.com
<<<<<<<<<<< End quote
Guess I will need to design one. Does anyone have any specifics on an adjustable lens cell or drawings to reference? Otherwise I will knock one out on Solidworks and see what it looks like.
Allan Overcast
Cloudy Skies Observatory
10" Meade RCX-400
80mm Homeade Refractor
Canon 350D Modified Camera
Pier-Tech 2 Pier
8' Exploradome
http://www.cloudyskies.org
--------------------
Allan Overcast
Cloudy Skies Observatory
10" Meade RCX-400
80mm Homeade Refractor
1277mm Homeade Refractor
Canon 350D Modified Camera
Q-Guider Camera
Pier-Tech 2 Pier
8' Exploradome
http://www.cloudyskies.org
|
dawsonian2000
professor emeritus
Reged: 07/26/06
Posts: 552
Loc: Riverview, FL, USA
|
|
You are welcome, Allan! I hope it will be a viable option for you. I was thinking about using the same setup, but I will stick with the Meade 127ED focuser I got from a friend. The only problem with this focuser is that its flange is smaller than my tube by 2 to 3 10ths of an inch in diameter. But, I can get it to work.
--------------------
Clear Skies, Forever!
The Vega Sky Center
10" (254mm) F/5.65 Home Built Fork Mounted Newtonian Reflector
5" (127mm) F/9.4 Home Built Refractor (under construction)
3.5" (90mm) F/11.1 "Vixen-Spec Modified" Konus Refractor
3.1" (80mm) F/6 Scopos ED APO Refractor
4.5" (114mm) F/8 Tasco 11te-5 Newtonian (under restoration)
2.4" (60mm) F/16.7 Tasco 7te-5 Refractor
2.4" (60mm) F/15 Jason Discoverer 313 Refractor
http://www.vega-sky-center.com
|
allanovercast
member
Reged: 08/02/07
Posts: 55
Loc: Billings, MT
|
|
Well I went out to our local irrigation parts supplier and picked up a 6", 0.058" wall, 48" aluminum tube yesterday for $30 and will see if I can make this work. It is a whole lot lighter and much less expensive if I make a mistake in the cutting of the tube. I have designed the lens cell to fit in the larger diameter tube and will consider the Antares J150 adapter plate for the larger tube. Otherwise I will design my own focuser adapter. I am leaning to initially use a wood lathe to make the parts, using hard wood, and verify they are close. Once verified I will have a machine shop mill them out of aluminum. Never know, the wood might work good enough to bypass the aluminum and the cost associated with it. I will update the pictures on the web site later today.
Allan Overcast
Cloudy Skies Observatory
10" Meade RCX-400
80mm Homeade Refractor
Canon 350D Modified Camera
Pier-Tech 2 Pier
8' Exploradome
http://www.cloudyskies.org
--------------------
Allan Overcast
Cloudy Skies Observatory
10" Meade RCX-400
80mm Homeade Refractor
1277mm Homeade Refractor
Canon 350D Modified Camera
Q-Guider Camera
Pier-Tech 2 Pier
8' Exploradome
http://www.cloudyskies.org
|
dawsonian2000
professor emeritus
Reged: 07/26/06
Posts: 552
Loc: Riverview, FL, USA
|
|
Hi Allan,
I see that you have gone to larger diameter and thinner wall thickness tube (6") for your 127mm refractor. Please let me know when you have redrawn your Solid Works designs and placed it on your website. BTW - I have added the Cloudy Skies Observatory to my list of favorite amateur astronomer websites on mine.
--------------------
Clear Skies, Forever!
The Vega Sky Center
10" (254mm) F/5.65 Home Built Fork Mounted Newtonian Reflector
5" (127mm) F/9.4 Home Built Refractor (under construction)
3.5" (90mm) F/11.1 "Vixen-Spec Modified" Konus Refractor
3.1" (80mm) F/6 Scopos ED APO Refractor
4.5" (114mm) F/8 Tasco 11te-5 Newtonian (under restoration)
2.4" (60mm) F/16.7 Tasco 7te-5 Refractor
2.4" (60mm) F/15 Jason Discoverer 313 Refractor
http://www.vega-sky-center.com
|
allanovercast
member
Reged: 08/02/07
Posts: 55
Loc: Billings, MT
|
|
Hello Mel, Will do, I almost have the coll. lens holder design completed and will post that and the scope mock-up tomorrow. I decided to go with the larger tube but smaller stock to lighten the load and remove any light loss from interference with the wall that I had with the smaller tube. I am itching to get the unit built so I hope to finish with the mechanical design issues this weekend.
Also thanks for the link. Once I get done with the design I will get the web page updated with the new obs pictures.
Allan Overcast
Cloudy Skies Observatory
10" Meade RCX-400
80mm Homeade Refractor
Canon 350D Modified Camera
Pier-Tech 2 Pier
8' Exploradome
http://www.cloudyskies.org
--------------------
Allan Overcast
Cloudy Skies Observatory
10" Meade RCX-400
80mm Homeade Refractor
1277mm Homeade Refractor
Canon 350D Modified Camera
Q-Guider Camera
Pier-Tech 2 Pier
8' Exploradome
http://www.cloudyskies.org
|
dawsonian2000
professor emeritus
Reged: 07/26/06
Posts: 552
Loc: Riverview, FL, USA
|
|
Hey Allan,
How will you go about determining the final length of your main tube based on the focal length and diagonal additions to the mix? I did a 1/2 scale ray trace for mine, which also includes scale models of my star diagonal, focuser, main tube, and objective with cell. I know some refractor ATMs use applications like OSLO, or ZEMAX, etc. But, I have also been told that I can use the ray trace I made by allowing the focal plane to extend about 1 to 2 inches above the top edge of the star diagonal with the focuser racked all the way in would also work. It makes sense to me but, since this is really the first true homebuilt astronomical refractor, I want to make certain I cut the main tube to the correct length. So, if you can offer any insight or resources it would be greatly appreciated.
P.S. I look forward to seeing the updates posted on your website.
Thanks,
--------------------
Clear Skies, Forever!
The Vega Sky Center
10" (254mm) F/5.65 Home Built Fork Mounted Newtonian Reflector
5" (127mm) F/9.4 Home Built Refractor (under construction)
3.5" (90mm) F/11.1 "Vixen-Spec Modified" Konus Refractor
3.1" (80mm) F/6 Scopos ED APO Refractor
4.5" (114mm) F/8 Tasco 11te-5 Newtonian (under restoration)
2.4" (60mm) F/16.7 Tasco 7te-5 Refractor
2.4" (60mm) F/15 Jason Discoverer 313 Refractor
http://www.vega-sky-center.com
|
allanovercast
member
Reged: 08/02/07
Posts: 55
Loc: Billings, MT
|
|
I've just uploaded the new changes to the design. I still am finishing the coll lens design, hopefully today! As for the tube length, I made an object 1200mm long, which is the focal length. I matched it with the front of the lens and have the prime focus point out the back ~3 inches with the focus barrel in all the way. When I put a 90 degree diagonal the path length utilizes the length out the back. When I put the camera, it also utilizes the length. If I need to move the prime focus point in, I simply move the focuser out, and walla! I will model my diagonal this weekend and add it to the drawing to see what I come up with.
I will also try to update the pictures of the observatory as it is now placed and wired for power so I can get back to enjoying Gods skies this weekend.
Allan Overcast
Cloudy Skies Observatory
10" Meade RCX-400
80mm Homeade Refractor
Canon 350D Modified Camera
Pier-Tech 2 Pier
8' Exploradome
http://www.cloudyskies.org
--------------------
Allan Overcast
Cloudy Skies Observatory
10" Meade RCX-400
80mm Homeade Refractor
1277mm Homeade Refractor
Canon 350D Modified Camera
Q-Guider Camera
Pier-Tech 2 Pier
8' Exploradome
http://www.cloudyskies.org
|
dawsonian2000
professor emeritus
Reged: 07/26/06
Posts: 552
Loc: Riverview, FL, USA
|
|
Thanks for the info, Allan! It will be very useful in helping me decide the length of the tube. I also just checked out the updated SolidWorks files on your website, and they look great.  It appears that I was on the right track with the ray trace, but I think I will have the focal plane protrude out the end a 2" star diagonal by about 1 to 1-1/2 inch. This should translate to approximately ~4 inches without the diagonal and the focuser racked all the way in.
I hope to start working on reducing the size of the focuser flange on tomorrow.
Thanks again,
Mel
--------------------
Clear Skies, Forever!
The Vega Sky Center
10" (254mm) F/5.65 Home Built Fork Mounted Newtonian Reflector
5" (127mm) F/9.4 Home Built Refractor (under construction)
3.5" (90mm) F/11.1 "Vixen-Spec Modified" Konus Refractor
3.1" (80mm) F/6 Scopos ED APO Refractor
4.5" (114mm) F/8 Tasco 11te-5 Newtonian (under restoration)
2.4" (60mm) F/16.7 Tasco 7te-5 Refractor
2.4" (60mm) F/15 Jason Discoverer 313 Refractor
http://www.vega-sky-center.com
|
dawsonian2000
professor emeritus
Reged: 07/26/06
Posts: 552
Loc: Riverview, FL, USA
|
|
Allan,
I was successful in removing the outer thickness of the focuser in order to fit it inside of the tube for the 127mm! I checked with my friend Curt to see if I could use his lathe to shave off the excess from the focuser, but the device was in need of repair. So, I came up with the idea of using my drill press equipped with a sanding drum to slowly and meticulously remove the excess. Using a scrap piece of 3/4" plywood, a couple of "C" clamps, and a couple of scrap Teflon pieces attached to the plywood, I was able to make a jig that did a marvelous job of reducing the diameter of the outside edge of the focuser's flange. The process worked great! It fits like a glove; well centered and snug. Now I don't have to make an adapter for the focuser to fit onto the main tube. I will attach a few images in a series of entries, which will convey the process I used and the end results.
Let me know what you think.
Mel
--------------------
Clear Skies, Forever!
The Vega Sky Center
10" (254mm) F/5.65 Home Built Fork Mounted Newtonian Reflector
5" (127mm) F/9.4 Home Built Refractor (under construction)
3.5" (90mm) F/11.1 "Vixen-Spec Modified" Konus Refractor
3.1" (80mm) F/6 Scopos ED APO Refractor
4.5" (114mm) F/8 Tasco 11te-5 Newtonian (under restoration)
2.4" (60mm) F/16.7 Tasco 7te-5 Refractor
2.4" (60mm) F/15 Jason Discoverer 313 Refractor
http://www.vega-sky-center.com
|
dawsonian2000
professor emeritus
Reged: 07/26/06
Posts: 552
Loc: Riverview, FL, USA
|
|
Here is an image of the focuser's flange being ground down.
--------------------
Clear Skies, Forever!
The Vega Sky Center
10" (254mm) F/5.65 Home Built Fork Mounted Newtonian Reflector
5" (127mm) F/9.4 Home Built Refractor (under construction)
3.5" (90mm) F/11.1 "Vixen-Spec Modified" Konus Refractor
3.1" (80mm) F/6 Scopos ED APO Refractor
4.5" (114mm) F/8 Tasco 11te-5 Newtonian (under restoration)
2.4" (60mm) F/16.7 Tasco 7te-5 Refractor
2.4" (60mm) F/15 Jason Discoverer 313 Refractor
http://www.vega-sky-center.com
|
dawsonian2000
professor emeritus
Reged: 07/26/06
Posts: 552
Loc: Riverview, FL, USA
|
|
This image shows the focuser inserted into the main tube after the focuser flange was ground down to the proper diameter to fit inside of the main tube. Not a bad fit!
Mel
--------------------
Clear Skies, Forever!
The Vega Sky Center
10" (254mm) F/5.65 Home Built Fork Mounted Newtonian Reflector
5" (127mm) F/9.4 Home Built Refractor (under construction)
3.5" (90mm) F/11.1 "Vixen-Spec Modified" Konus Refractor
3.1" (80mm) F/6 Scopos ED APO Refractor
4.5" (114mm) F/8 Tasco 11te-5 Newtonian (under restoration)
2.4" (60mm) F/16.7 Tasco 7te-5 Refractor
2.4" (60mm) F/15 Jason Discoverer 313 Refractor
http://www.vega-sky-center.com
|
dawsonian2000
professor emeritus
Reged: 07/26/06
Posts: 552
Loc: Riverview, FL, USA
|
|
Here is a photo of the focuser and tube before grinding. The fit was off by about a couple of millimeters.
--------------------
Clear Skies, Forever!
The Vega Sky Center
10" (254mm) F/5.65 Home Built Fork Mounted Newtonian Reflector
5" (127mm) F/9.4 Home Built Refractor (under construction)
3.5" (90mm) F/11.1 "Vixen-Spec Modified" Konus Refractor
3.1" (80mm) F/6 Scopos ED APO Refractor
4.5" (114mm) F/8 Tasco 11te-5 Newtonian (under restoration)
2.4" (60mm) F/16.7 Tasco 7te-5 Refractor
2.4" (60mm) F/15 Jason Discoverer 313 Refractor
http://www.vega-sky-center.com
Edited by dawsonian2000 (02/09/09 06:00 PM)
|
allanovercast
member
Reged: 08/02/07
Posts: 55
Loc: Billings, MT
|
|
Mel, that looks really nice. I finished the colliminating mount for the 6" tube so I will "try" to get the updated drawings loaded. I did my ray trace with the section view in the CAD program and extended the prime focus point out 3.5 inches. If you have an eyepiece that can't focus they make 2" barrel extensions to bring the eyepiece out farther, they work well. I have not started assembling, needed to finish some honey do's as well as observatory powering and placement of the scope/pier. The 24" pier seemed to work well, but the weather decided to come in before I got everything calibrated; figures.
Must run, have an oil leak I need to locate on teh wifes vehicle.
Allan Overcast
Cloudy Skies Observatory
10" Meade RCX-400
80mm Homeade Refractor
Canon 350D Modified Camera
Pier-Tech 2 Pier
8' Exploradome
http://www.cloudyskies.org
--------------------
Allan Overcast
Cloudy Skies Observatory
10" Meade RCX-400
80mm Homeade Refractor
1277mm Homeade Refractor
Canon 350D Modified Camera
Q-Guider Camera
Pier-Tech 2 Pier
8' Exploradome
http://www.cloudyskies.org
|
dawsonian2000
professor emeritus
Reged: 07/26/06
Posts: 552
Loc: Riverview, FL, USA
|
|
Hi Allan,
I have not started assembly either. My first plans are to get all of the individual components to fit the main tube perfectly before moving on to the assembly of the OTA. Now that I got the focuser to fit the way I wanted it to, I will move on to the cradle ring clamps. Made from very hard and durable Teak wood, they will look similar in design to the aluminum CNC cut "C" clamp style cradles rings commonly used on high-end refractors. I already made the tracing templates to transpose the design to the wood, and I am ready to cut them out. I will post some photos later.
After the cradle ring clamps are done, I will move on to baffling the tube.
So what made you decide on having your focal plane stick out 3.5" from the end of the "racked in" focuser? I think you have found the "sweet spot" for sure! As for extension tubes, I have a couple of 2" extension tubes (50mm and 80mm)in my arsenal to use in the event I do not have enough focuser travel. I will be checking your site for the new renderings.
--------------------
Clear Skies, Forever!
The Vega Sky Center
10" (254mm) F/5.65 Home Built Fork Mounted Newtonian Reflector
5" (127mm) F/9.4 Home Built Refractor (under construction)
3.5" (90mm) F/11.1 "Vixen-Spec Modified" Konus Refractor
3.1" (80mm) F/6 Scopos ED APO Refractor
4.5" (114mm) F/8 Tasco 11te-5 Newtonian (under restoration)
2.4" (60mm) F/16.7 Tasco 7te-5 Refractor
2.4" (60mm) F/15 Jason Discoverer 313 Refractor
http://www.vega-sky-center.com
|
dawsonian2000
professor emeritus
Reged: 07/26/06
Posts: 552
Loc: Riverview, FL, USA
|
|
This is a diagram with measurements depicting the cradle ring clamps that I will be constructing for the 127mm f/9.4 refractor.
Mel
--------------------
Clear Skies, Forever!
The Vega Sky Center
10" (254mm) F/5.65 Home Built Fork Mounted Newtonian Reflector
5" (127mm) F/9.4 Home Built Refractor (under construction)
3.5" (90mm) F/11.1 "Vixen-Spec Modified" Konus Refractor
3.1" (80mm) F/6 Scopos ED APO Refractor
4.5" (114mm) F/8 Tasco 11te-5 Newtonian (under restoration)
2.4" (60mm) F/16.7 Tasco 7te-5 Refractor
2.4" (60mm) F/15 Jason Discoverer 313 Refractor
http://www.vega-sky-center.com
Edited by dawsonian2000 (02/10/09 03:36 AM)
|
dawsonian2000
professor emeritus
Reged: 07/26/06
Posts: 552
Loc: Riverview, FL, USA
|
|
This is an image of the top and bottom sections of the Cradle Ring Clamp templates arranged on top of the Teak wood stock ready for tracing.
Mel
--------------------
Clear Skies, Forever!
The Vega Sky Center
10" (254mm) F/5.65 Home Built Fork Mounted Newtonian Reflector
5" (127mm) F/9.4 Home Built Refractor (under construction)
3.5" (90mm) F/11.1 "Vixen-Spec Modified" Konus Refractor
3.1" (80mm) F/6 Scopos ED APO Refractor
4.5" (114mm) F/8 Tasco 11te-5 Newtonian (under restoration)
2.4" (60mm) F/16.7 Tasco 7te-5 Refractor
2.4" (60mm) F/15 Jason Discoverer 313 Refractor
http://www.vega-sky-center.com
Edited by dawsonian2000 (02/10/09 03:58 AM)
|
dawsonian2000
professor emeritus
Reged: 07/26/06
Posts: 552
Loc: Riverview, FL, USA
|
|
Here the Cradle Ring Clamp sections have been traced onto the wood and are ready for cutting on my band saw.
Mel
--------------------
Clear Skies, Forever!
The Vega Sky Center
10" (254mm) F/5.65 Home Built Fork Mounted Newtonian Reflector
5" (127mm) F/9.4 Home Built Refractor (under construction)
3.5" (90mm) F/11.1 "Vixen-Spec Modified" Konus Refractor
3.1" (80mm) F/6 Scopos ED APO Refractor
4.5" (114mm) F/8 Tasco 11te-5 Newtonian (under restoration)
2.4" (60mm) F/16.7 Tasco 7te-5 Refractor
2.4" (60mm) F/15 Jason Discoverer 313 Refractor
http://www.vega-sky-center.com
|
dawsonian2000
professor emeritus
Reged: 07/26/06
Posts: 552
Loc: Riverview, FL, USA
|
|
This a diagram of the Cradle Ring Clamp as rendered in MS Paint. The large gray oval represents one of the aluminum pivot plates that will be mounted on both sides of each ring clamp, while the small circles are the aluminum dowel nuts that will be used to mount the rings to the EQ mount, and to lock the lock to clamp around the telescope tube. I may change the later to a t-nut arrangement.
Mel
--------------------
Clear Skies, Forever!
The Vega Sky Center
10" (254mm) F/5.65 Home Built Fork Mounted Newtonian Reflector
5" (127mm) F/9.4 Home Built Refractor (under construction)
3.5" (90mm) F/11.1 "Vixen-Spec Modified" Konus Refractor
3.1" (80mm) F/6 Scopos ED APO Refractor
4.5" (114mm) F/8 Tasco 11te-5 Newtonian (under restoration)
2.4" (60mm) F/16.7 Tasco 7te-5 Refractor
2.4" (60mm) F/15 Jason Discoverer 313 Refractor
http://www.vega-sky-center.com
|
allanovercast
member
Reged: 08/02/07
Posts: 55
Loc: Billings, MT
|
|
The drawings look really nice, will be interested in seeing the outcome. I have some new drawings and plan on cutting the 5" tube tomorrow evening. I will use a chop saw with a metal cutting blade on it, I don't have any special machines to use, so I must improvise.
As for the distance out the back, I chose 3-1/2" with the focus tube in all the way and ~1" with the tube out at max. This will allow for a decent focus travel depending on what lens I use. When using the DSLR camera I may need to use an extension tube to extend the focus range. If I make the back focus to short the diagonal can not be focused. I will post the latest drawings and dimensions once I cut the tube tomorrow.
Allan Overcast
Cloudy Skies Observatory
10" Meade RCX-400
80mm Homeade Refractor
Canon 350D Modified Camera
Pier-Tech 2 Pier
8' Exploradome
http://www.cloudyskies.org
--------------------
Allan Overcast
Cloudy Skies Observatory
10" Meade RCX-400
80mm Homeade Refractor
1277mm Homeade Refractor
Canon 350D Modified Camera
Q-Guider Camera
Pier-Tech 2 Pier
8' Exploradome
http://www.cloudyskies.org
|
dawsonian2000
professor emeritus
Reged: 07/26/06
Posts: 552
Loc: Riverview, FL, USA
|
|
Thanks Allan! Yes, it will be interesting to see how both of ours turn out. I am currently thinking about what method I will use to have my tube cut. I like the idea of using a chop saw, but I do not own one, or know anyone who does. So my next option would be to have a shop do it for me. There should be a number of places in my area I could use. I will keep you posted.
This weekend I will be cutting out the cradle ring clamps and possibly the baffles. I am going to use only two in the mix.
I will be checking out your website for your updates. Pretty soon I will start building the construction overview pages of this telescope on my website. But, I am not quite ready yet.
BTW - If you subscribe to Astronomy Technology Today, be on the lookout for an article I wrote on the building of an inexpensive wooden field tripod. It should appear in the next issue. My first article about the construction of my 10” f/5.6 Fork Mounted Newtonian appeared in their debut issue.
Mel
--------------------
Clear Skies, Forever!
The Vega Sky Center
10" (254mm) F/5.65 Home Built Fork Mounted Newtonian Reflector
5" (127mm) F/9.4 Home Built Refractor (under construction)
3.5" (90mm) F/11.1 "Vixen-Spec Modified" Konus Refractor
3.1" (80mm) F/6 Scopos ED APO Refractor
4.5" (114mm) F/8 Tasco 11te-5 Newtonian (under restoration)
2.4" (60mm) F/16.7 Tasco 7te-5 Refractor
2.4" (60mm) F/15 Jason Discoverer 313 Refractor
http://www.vega-sky-center.com
|
allanovercast
member
Reged: 08/02/07
Posts: 55
Loc: Billings, MT
|
|
I took my tube yesterday to a hydrolic machine shop and they are cutting it on a lathe. It will cost ~$30, but that was cheaper that purchasing a tool to do it. I settled on 38-3/4" for the tube length, and rechecked all my measurements from the front of the objective to the exit point at the back.
Using the Solidworks models I came up with, at max focus, 0.215" back focus, and at minimum focus ~3.1". So I will find out tonight when I put the pieces together how it works.
Allan Overcast
Cloudy Skies Observatory
10" Meade RCX-400
80mm Homeade Refractor
Canon 350D Modified Camera
Pier-Tech 2 Pier
8' Exploradome
http://www.cloudyskies.org
--------------------
Allan Overcast
Cloudy Skies Observatory
10" Meade RCX-400
80mm Homeade Refractor
1277mm Homeade Refractor
Canon 350D Modified Camera
Q-Guider Camera
Pier-Tech 2 Pier
8' Exploradome
http://www.cloudyskies.org
|
rboe
Reged: 03/16/02
Posts: 45311
Loc: Phx, AZ
|
|
You guys have me thinking - not a good idea. Surplus Shed has the F5.5 lense in stock now. Anyone one know how the CA compares to the longer focal length? That shot of the moon posted earlier does not appear to be too bad at all. Better than a fast 102mm I have now.
--------------------
Ron
NS11GPS
Pronto
16" dob
15X70 Obies
|
dawsonian2000
professor emeritus
Reged: 07/26/06
Posts: 552
Loc: Riverview, FL, USA
|
|
Wow! Can't wait to read the results of your optical test. Please post them soon! BTW - You may have already posted this, but what is the total height of your focus "all the way in"?
Mel
--------------------
Clear Skies, Forever!
The Vega Sky Center
10" (254mm) F/5.65 Home Built Fork Mounted Newtonian Reflector
5" (127mm) F/9.4 Home Built Refractor (under construction)
3.5" (90mm) F/11.1 "Vixen-Spec Modified" Konus Refractor
3.1" (80mm) F/6 Scopos ED APO Refractor
4.5" (114mm) F/8 Tasco 11te-5 Newtonian (under restoration)
2.4" (60mm) F/16.7 Tasco 7te-5 Refractor
2.4" (60mm) F/15 Jason Discoverer 313 Refractor
http://www.vega-sky-center.com
Edited by dawsonian2000 (02/12/09 07:59 PM)
|
dawsonian2000
professor emeritus
Reged: 07/26/06
Posts: 552
Loc: Riverview, FL, USA
|
|
Ron,
I checked SS and found that the 127mm f/5.5 ojectives were out of stock. I know when they get them in, they do not last long, but that was really lightning quick.
As for as CA in the f/5.5 as compared to the f/9.4, I would say the f/9.4 would win, based on my intuition. Unfortuantely, I can not say for sure. Others may have a different say. Hey Allan, Scubaguy, Preston, etc.! ...any ideas on this one?
Mel
--------------------
Clear Skies, Forever!
The Vega Sky Center
10" (254mm) F/5.65 Home Built Fork Mounted Newtonian Reflector
5" (127mm) F/9.4 Home Built Refractor (under construction)
3.5" (90mm) F/11.1 "Vixen-Spec Modified" Konus Refractor
3.1" (80mm) F/6 Scopos ED APO Refractor
4.5" (114mm) F/8 Tasco 11te-5 Newtonian (under restoration)
2.4" (60mm) F/16.7 Tasco 7te-5 Refractor
2.4" (60mm) F/15 Jason Discoverer 313 Refractor
http://www.vega-sky-center.com
|
allanovercast
member
Reged: 08/02/07
Posts: 55
Loc: Billings, MT
|
|
Well I received my milled tube back today and it looks great. They charged me a little more that over the phone; guess those shop supplies add up! The ends are nice and true and smooth but when placing the lens over the tube it did not fit very well. It seems that the plastic molding process swelled a little bit around the center of the holder. I had to remove the glass, and sand on the inside of the plastic to shave it down so it will fit. My only concern is the lip that stops the tube and holds the lens my not be perfectly true after the sanding. I will use a digital level we have at work to verify the tube's square then compare the lens mount to verify.
Tomorrow I will drill the lens and focuser holes so I can get those mounted before I paint the tube. I will verify the focus travel with a diagonal and the camera before painting. But on a brighter note, had 30 minutes of observatory time with the RCX400 before the clouds moved in, oh what wonder!
Allan Overcast
Cloudy Skies Observatory
10" Meade RCX-400
80mm Homeade Refractor
Canon 350D Modified Camera
Pier-Tech 2 Pier
8' Exploradome
http://www.cloudyskies.org
--------------------
Allan Overcast
Cloudy Skies Observatory
10" Meade RCX-400
80mm Homeade Refractor
1277mm Homeade Refractor
Canon 350D Modified Camera
Q-Guider Camera
Pier-Tech 2 Pier
8' Exploradome
http://www.cloudyskies.org
|
dawsonian2000
professor emeritus
Reged: 07/26/06
Posts: 552
Loc: Riverview, FL, USA
|
|
When I initially test fitted my lens cell to my tube, it actually slid on quite well. Just the last 20% near the lens retainer narrows forming a snug fit. So, when I paint my tube, I will leave about a couple of inches of the tube unpainted.
I will have to pull out the big gun (my 10" f/5.6 Newt) this weekend for a fix.
Waiting impatiently for your results.
Mel
--------------------
Clear Skies, Forever!
The Vega Sky Center
10" (254mm) F/5.65 Home Built Fork Mounted Newtonian Reflector
5" (127mm) F/9.4 Home Built Refractor (under construction)
3.5" (90mm) F/11.1 "Vixen-Spec Modified" Konus Refractor
3.1" (80mm) F/6 Scopos ED APO Refractor
4.5" (114mm) F/8 Tasco 11te-5 Newtonian (under restoration)
2.4" (60mm) F/16.7 Tasco 7te-5 Refractor
2.4" (60mm) F/15 Jason Discoverer 313 Refractor
http://www.vega-sky-center.com
|
allanovercast
member
Reged: 08/02/07
Posts: 55
Loc: Billings, MT
|
|
I finally had some time to put towards the project, work and life seem to get in the way.
I mounted the lens, after some major sanding to get the lens cell to fit over the pipe. The focuser attached pretty easily, but determined that I will need some stock to ensure a solid attachment. Initially I used a 16mm 1.25" eyepiece w/o the diagonal and was able to get good focus range. I also tried a 26mm 2" eyepiece with similar results. Now comes the issues...
When I put the diagonal in line I could not obtain focus on either eyepieces. After measuring the diagonal I found 3-1/2" path for the 2" eyepiece and 4.9" for the 1.25" eyepiece; much longer than I accounted for.
So I guess the quandry is as follows. Do I mandate the use of a diagonal? Is the intended use of the instrument for imaging or viewing? Prime focus is measured to the eye side of the eyepiece therefore barlows will also be required to be figured in for the focus measurement.
I will post an updated drawing based on my current findings.
Allan Overcast
Cloudy Skies Observatory
10" Meade RCX-400
80mm Homeade Refractor
Canon 350D Modified Camera
Pier-Tech 2 Pier
8' Exploradome
http://www.cloudyskies.org
--------------------
Allan Overcast
Cloudy Skies Observatory
10" Meade RCX-400
80mm Homeade Refractor
1277mm Homeade Refractor
Canon 350D Modified Camera
Q-Guider Camera
Pier-Tech 2 Pier
8' Exploradome
http://www.cloudyskies.org
|
George55
super member
Reged: 04/14/08
Posts: 118
Loc: North Texas, USA
|
|
Quote:
I finally had some time to put towards the project, work and life seem to get in the way.
I mounted the lens, after some major sanding to get the lens cell to fit over the pipe. The focuser attached pretty easily, but determined that I will need some stock to ensure a solid attachment. Initially I used a 16mm 1.25" eyepiece w/o the diagonal and was able to get good focus range. I also tried a 26mm 2" eyepiece with similar results. Now comes the issues...
When I put the diagonal in line I could not obtain focus on either eyepieces. After measuring the diagonal I found 3-1/2" path for the 2" eyepiece and 4.9" for the 1.25" eyepiece; much longer than I accounted for.
So I guess the quandry is as follows. Do I mandate the use of a diagonal? Is the intended use of the instrument for imaging or viewing? Prime focus is measured to the eye side of the eyepiece therefore barlows will also be required to be figured in for the focus measurement.
I will post an updated drawing based on my current findings.
Allan Overcast
Cloudy Skies Observatory
10" Meade RCX-400
80mm Homeade Refractor
Canon 350D Modified Camera
Pier-Tech 2 Pier
8' Exploradome
http://www.cloudyskies.org
I used the "telescope on a stick" trick when I made my 127mm refractor. I found the tube length has to be much shorter using a 2" diagonal and barlow. I went with a tube length that will allow for their use and figured I can always go with a focuser tube extender or make a longer focuser tube if I want to view straight through. I like the confort of viewing with a diagonal in most cases.
George
|
dawsonian2000
professor emeritus
Reged: 07/26/06
Posts: 552
Loc: Riverview, FL, USA
|
|
Hi Allan,
Sorry to know that your setup will not allow for the use of a diagonal. But, it sounds like you could benefit from trimming a bit more of your tube. Of recent, I moved away from my 1/2 scale ray trace design and made a full sized one. I factored in my 2" diagonal and came up with a measurement that was closer to George's tube length; about 36" inches. Of course my focuser is approximately of similar length to George's, possessing a good deal of travel (6" inches). If you plan on using it for visual use, you will want to use your diagonal (as if you do not already know  ). But, if you want to use it strictly for prime focus imaging, it may be the right length. As long as you have enough back focus to focus the image on the CCD of your choice of imager. I know you will make the right decision. At least you did not cut off too much of the tube, which would have been catastrophic.
I wish I knew a standard back-focus distance. In my research, I have found that high-end refractor makers (like Takahashi) have enormous amounts of back-focus (something like 7.5" inches). But, I know I can not do that with my setup. Nevertheless, their must be a general standard out their that conveys this distance. I think I will go with about 1.5" to 2.5" of back-focus using my 2" diagonal as my common ground. Without the diagonal, the scope then would render about 4" extra inches to the mix, making a total of around 5.5" to 6.5" of back-focus. This is not "said and done", so my research continues.
Look forward to reading your update and I will keep you posted on my efforts as well.
Good Luck,
Mel
--------------------
Clear Skies, Forever!
The Vega Sky Center
10" (254mm) F/5.65 Home Built Fork Mounted Newtonian Reflector
5" (127mm) F/9.4 Home Built Refractor (under construction)
3.5" (90mm) F/11.1 "Vixen-Spec Modified" Konus Refractor
3.1" (80mm) F/6 Scopos ED APO Refractor
4.5" (114mm) F/8 Tasco 11te-5 Newtonian (under restoration)
2.4" (60mm) F/16.7 Tasco 7te-5 Refractor
2.4" (60mm) F/15 Jason Discoverer 313 Refractor
http://www.vega-sky-center.com
|
allanovercast
member
Reged: 08/02/07
Posts: 55
Loc: Billings, MT
|
|
I need an additional 2-1/2 inches, hmmm that puts the length at.. 36-1/4 inches. The back focus distance has always been a question, so I will have them cut an additional 2-1/2 inches off. I can always add length back for the camera, but I will need the diagonal. I tried w/o and my neck is still stiff!
I hope to have this done by the weekend, will see!
Allan Overcast
Cloudy Skies Observatory
10" Meade RCX-400
80mm Homeade Refractor
Canon 350D Modified Camera
Pier-Tech 2 Pier
8' Exploradome
http://www.cloudyskies.org
--------------------
Allan Overcast
Cloudy Skies Observatory
10" Meade RCX-400
80mm Homeade Refractor
1277mm Homeade Refractor
Canon 350D Modified Camera
Q-Guider Camera
Pier-Tech 2 Pier
8' Exploradome
http://www.cloudyskies.org
|
Happy-Idiot
Carpal Tunnel
Reged: 04/06/06
Posts: 2801
Loc: 3rd Rock
|
|
Quote:
Hmmm, interesting and it will fit outside the tube. I will check into this. It would help stablize the focuser and would look much better.
Thanks!
Allan Overcast
Cloudy Skies Observatory
10" Meade RCX-400
80mm Homeade Refractor
Canon 350D Modified Camera
Pier-Tech 2 Pier
8' Exploradome
http://www.cloudyskies.org
Here is how i did my 127mm SS . I used the adaptor plate and i have to say i like it but yours looks much nicer.
I put my ATM to the side for the moment due to some longer work hours but after reading your post i feel like finishing it.
--------------------
Brian
A small scope that gets used often is a better investment than a big scope that stays in the closet.
Unitrons, you spend more time looking at them than you do through them.
|
dawsonian2000
professor emeritus
Reged: 07/26/06
Posts: 552
Loc: Riverview, FL, USA
|
|
I agree, George. Nothing like a diagonal to reduce the neck cramps when viewing objects high up.
BTW - How does you 127mm perform?
--------------------
Clear Skies, Forever!
The Vega Sky Center
10" (254mm) F/5.65 Home Built Fork Mounted Newtonian Reflector
5" (127mm) F/9.4 Home Built Refractor (under construction)
3.5" (90mm) F/11.1 "Vixen-Spec Modified" Konus Refractor
3.1" (80mm) F/6 Scopos ED APO Refractor
4.5" (114mm) F/8 Tasco 11te-5 Newtonian (under restoration)
2.4" (60mm) F/16.7 Tasco 7te-5 Refractor
2.4" (60mm) F/15 Jason Discoverer 313 Refractor
http://www.vega-sky-center.com
|
dawsonian2000
professor emeritus
Reged: 07/26/06
Posts: 552
Loc: Riverview, FL, USA
|
|
Sounds like a great plan, Allan. Happy that you have decided to include the star diagonal to your setup. I hope the next tube cut will put you right on the spot.
This weekend I hope to get the cradle rings cut out, as well as my tube cut to size. After adding the focuser to my ray trace, I came up with a tube length of 35.5" inches. This will allow for the focal plane to produce a back-focus distance of 1.8" inches above the end of my 2" star diagonal with the focuser racked all the way in. With 6" inches of focuser travel to work with, I think I will be good. I may need to use an extension tube when imaging with a DSLR though, but I am fine with that.
Mel
--------------------
Clear Skies, Forever!
The Vega Sky Center
10" (254mm) F/5.65 Home Built Fork Mounted Newtonian Reflector
5" (127mm) F/9.4 Home Built Refractor (under construction)
3.5" (90mm) F/11.1 "Vixen-Spec Modified" Konus Refractor
3.1" (80mm) F/6 Scopos ED APO Refractor
4.5" (114mm) F/8 Tasco 11te-5 Newtonian (under restoration)
2.4" (60mm) F/16.7 Tasco 7te-5 Refractor
2.4" (60mm) F/15 Jason Discoverer 313 Refractor
http://www.vega-sky-center.com
|
George55
super member
Reged: 04/14/08
Posts: 118
Loc: North Texas, USA
|
|
Quote:
I agree, George. Nothing like a diagonal to reduce the neck cramps when viewing objects high up.
BTW - How does you 127mm perform?
Mel,
It is not an APO, but it does perform very well. I collimated the focuser and lens for best possible alignment. I have not had very good viewing weather, but one night I saw great detail in the Orion Nebula. I have also had some nice views of the moon and Venus with it.
I am well pleased with it.
George
|
dawsonian2000
professor emeritus
Reged: 07/26/06
Posts: 552
Loc: Riverview, FL, USA
|
|
Thanks for the performance notes, George. Now I thirst even more to get this project completed. But, I will be patient. I have a friend who is a metal worker and I plan to commission him to make a collimatable cell from the instrument. He does great work. He built a custom clock drive and the RA axis bushings for my 10" fork mounted Newtonian not long ago. So, my completion time may be extended a bit.
When time and sky conditions work in your favor for observing, please post more of your performance notes.
Thanks,
Mel
--------------------
Clear Skies, Forever!
The Vega Sky Center
10" (254mm) F/5.65 Home Built Fork Mounted Newtonian Reflector
5" (127mm) F/9.4 Home Built Refractor (under construction)
3.5" (90mm) F/11.1 "Vixen-Spec Modified" Konus Refractor
3.1" (80mm) F/6 Scopos ED APO Refractor
4.5" (114mm) F/8 Tasco 11te-5 Newtonian (under restoration)
2.4" (60mm) F/16.7 Tasco 7te-5 Refractor
2.4" (60mm) F/15 Jason Discoverer 313 Refractor
http://www.vega-sky-center.com
|
dawsonian2000
professor emeritus
Reged: 07/26/06
Posts: 552
Loc: Riverview, FL, USA
|
|
Hey Brian,
You most definitley should complete the work on your scope. I love the idea you have of using old CD's as baffles. The "stone creations" application will not only secure your CD's prior to sealing, its textured finish should also help in increasing contrast. Get moving again on that project, dude! Great photos and detailed overview of your 127mm project.
Mel
--------------------
Clear Skies, Forever!
The Vega Sky Center
10" (254mm) F/5.65 Home Built Fork Mounted Newtonian Reflector
5" (127mm) F/9.4 Home Built Refractor (under construction)
3.5" (90mm) F/11.1 "Vixen-Spec Modified" Konus Refractor
3.1" (80mm) F/6 Scopos ED APO Refractor
4.5" (114mm) F/8 Tasco 11te-5 Newtonian (under restoration)
2.4" (60mm) F/16.7 Tasco 7te-5 Refractor
2.4" (60mm) F/15 Jason Discoverer 313 Refractor
http://www.vega-sky-center.com
|
allanovercast
member
Reged: 08/02/07
Posts: 55
Loc: Billings, MT
|
|
Well off to the machine shop, a new one just down the road from my office, hope to get the reqorked tube back tomorrow. I can see that my next piece of shop equipment will be a combo metal drill/lathe bench. I decided that 36" was within 1/4" of what you two (Mel and George) decided upon, so I decided that 1/4" did not matter so much. My focuser only has 2-5/8" travel so I need to be close. It is an Antares dual speed crawford focuser.
I don't have the mechanical gift like you gentlemen have, but we all have different gifts bestowed on us. I enjoy seeing the art that your doing on your systems, I hope mine will come out somewhat close as my design say's it will. I hope to test out the non-painted unit this weekend, but 4" of snow tomorrow.
Allan Overcast
Cloudy Skies Observatory
10" Meade RCX-400
80mm Homeade Refractor
Canon 350D Modified Camera
Pier-Tech 2 Pier
8' Exploradome
http://www.cloudyskies.org
--------------------
Allan Overcast
Cloudy Skies Observatory
10" Meade RCX-400
80mm Homeade Refractor
1277mm Homeade Refractor
Canon 350D Modified Camera
Q-Guider Camera
Pier-Tech 2 Pier
8' Exploradome
http://www.cloudyskies.org
|
George55
super member
Reged: 04/14/08
Posts: 118
Loc: North Texas, USA
|
|
Quote:
Well off to the machine shop, a new one just down the road from my office, hope to get the reqorked tube back tomorrow. I can see that my next piece of shop equipment will be a combo metal drill/lathe bench. I decided that 36" was within 1/4" of what you two (Mel and George) decided upon, so I decided that 1/4" did not matter so much. My focuser only has 2-5/8" travel so I need to be close. It is an Antares dual speed crawford focuser.
I don't have the mechanical gift like you gentlemen have, but we all have different gifts bestowed on us. I enjoy seeing the art that your doing on your systems, I hope mine will come out somewhat close as my design say's it will. I hope to test out the non-painted unit this weekend, but 4" of snow tomorrow.
Allan Overcast
Cloudy Skies Observatory
10" Meade RCX-400
80mm Homeade Refractor
Canon 350D Modified Camera
Pier-Tech 2 Pier
8' Exploradome
http://www.cloudyskies.org
Allan,
I trued the ends of my tube up on a radial arm saw with a metal cutoff wheel in it. To do this, I made a wooden jig for it to fit in and rotate smoothly. The jig was two pcs. of wood nailed together in a "L" shape with an end nailed on it so any high part of the opposite end of the tube would always be in contact with it. I then brought the cutoff wheel into the tube and locked the saw on the arm and rotated the tube. I kept going deeper until I went all the way through the tube. It came out perfectly square on the ends.
My metal turning lathe is a 10" swing over the bed but only has a 1" hole in the spindle. The length between centers is only 3'. Being an old ex-machinist, I have learned a lot of work arounds when I don't have the exact tool I need to make a job easier. The only mill I have is a small attachment that fits on the cross slide of my lathe (see drilling the holes in the focuser on my post "127mm refractor project finished") and my drill press is a $59.00 bench top that I have used for over a dozen years now. The more you build, the more work arounds you will learn.
I think you are doing a fine job on your scope. One plus is that you are not rushing it. Hang in there and you will love the results.
|
dawsonian2000
professor emeritus
Reged: 07/26/06
Posts: 552
Loc: Riverview, FL, USA
|
|
Quote:
I don't have the mechanical gift like you gentlemen have, but we all have different gifts bestowed on us.
You have got to be kidding, right Allan! You have done a fantastic job with your telescope. I am sure that it will look and perform acceptional once it is complete. I wish I were able to do the rendering you do with SolidWorks. Just wonderful work you have done.
You and George have definitely been an inspiration to me as I endeavor to "do the right thing" to get my 127mm constructed. I have avoided a lot of headaches thanks to you both, as well as Scubaguy. I know once you are done with it, you will become a valuable source of information for many.
Mel
--------------------
Clear Skies, Forever!
The Vega Sky Center
10" (254mm) F/5.65 Home Built Fork Mounted Newtonian Reflector
5" (127mm) F/9.4 Home Built Refractor (under construction)
3.5" (90mm) F/11.1 "Vixen-Spec Modified" Konus Refractor
3.1" (80mm) F/6 Scopos ED APO Refractor
4.5" (114mm) F/8 Tasco 11te-5 Newtonian (under restoration)
2.4" (60mm) F/16.7 Tasco 7te-5 Refractor
2.4" (60mm) F/15 Jason Discoverer 313 Refractor
http://www.vega-sky-center.com
|
allanovercast
member
Reged: 08/02/07
Posts: 55
Loc: Billings, MT
|
|
Mel I can design an advance DSPO based communications system controller in my sleep, but I can't cut a straight line. Anyone can draw, but moving that from the drawing to reality takes work. So will see how it comes out!
Well got the milled trube back today, about choked that the milling came back 3 times more than the "estimate". The reason? the tube was not completely round inside. I made a change to the design and had 12" of the inside of the tube milled down with a draft angle of 2 degrees. I minimized the tube from 4.50"ID to 4.850"ID to remove any interference from the tube.
The initial results are good. Good focus with the diagonal and a 2" eyepiece, 50% focus position. The 1.25" eyepiece is also good. The DSLR (Canon Digital Rebel) does not focus on either with and w/o the diagonal. That was expected. With focus at the minimum the DSLR was almost in focus, so a 2-1/2" tube extension will be necessary, so no problem.
All for now, clearing off tonight, clearer tomorrow,
Allan Overcast
Cloudy Skies Observatory
10" Meade RCX-400
80mm Homeade Refractor
Canon 350D Modified Camera
Pier-Tech 2 Pier
8' Exploradome
http://www.cloudyskies.org
--------------------
Allan Overcast
Cloudy Skies Observatory
10" Meade RCX-400
80mm Homeade Refractor
1277mm Homeade Refractor
Canon 350D Modified Camera
Q-Guider Camera
Pier-Tech 2 Pier
8' Exploradome
http://www.cloudyskies.org
|
dawsonian2000
professor emeritus
Reged: 07/26/06
Posts: 552
Loc: Riverview, FL, USA
|
|
Congrats, Allan!  It appears your second attempt at getting the tube length nailed has worked! Great to know that you are now able to use both your 1.25" and 2" eyepieces. As for imaging, I also figure that I will have to use my extension tube with my DSLR.
Over the past weekend I did not get any work done on my 127mm, but I did on yesterday and today. I completed cutting out the four teak wood cradle ring halves and the aluminum hinge brackets used to attach the halves. I will post some photos later.
Again Congrats and look forward to your updates.
Mel
--------------------
Clear Skies, Forever!
The Vega Sky Center
10" (254mm) F/5.65 Home Built Fork Mounted Newtonian Reflector
5" (127mm) F/9.4 Home Built Refractor (under construction)
3.5" (90mm) F/11.1 "Vixen-Spec Modified" Konus Refractor
3.1" (80mm) F/6 Scopos ED APO Refractor
4.5" (114mm) F/8 Tasco 11te-5 Newtonian (under restoration)
2.4" (60mm) F/16.7 Tasco 7te-5 Refractor
2.4" (60mm) F/15 Jason Discoverer 313 Refractor
http://www.vega-sky-center.com
|
dawsonian2000
professor emeritus
Reged: 07/26/06
Posts: 552
Loc: Riverview, FL, USA
|
|
This is a photo of the Teak Cradle Clamp halves. I still have to drill a couple of holes in the two bottom halves to insert dowel nuts to attach them to the EQ. Also, I am further contemplating what type of system I will use to secure the to halves around the telescope tube. George's design is one I have in mind. If I go with his system, I would require only one per clamp set rather than the two as George incorporated into his design.
Mel
--------------------
Clear Skies, Forever!
The Vega Sky Center
10" (254mm) F/5.65 Home Built Fork Mounted Newtonian Reflector
5" (127mm) F/9.4 Home Built Refractor (under construction)
3.5" (90mm) F/11.1 "Vixen-Spec Modified" Konus Refractor
3.1" (80mm) F/6 Scopos ED APO Refractor
4.5" (114mm) F/8 Tasco 11te-5 Newtonian (under restoration)
2.4" (60mm) F/16.7 Tasco 7te-5 Refractor
2.4" (60mm) F/15 Jason Discoverer 313 Refractor
http://www.vega-sky-center.com
|
dawsonian2000
professor emeritus
Reged: 07/26/06
Posts: 552
Loc: Riverview, FL, USA
|
|
In creating a hinged system to connect the two cradle ring halves, I will use these four pieces of aluminum. More finishing work is need on them. Holes will have to be drilled and a brushed finish applied. I stole this design from telescopes like the Tasco 7te-5 and many cradles from 114mm reflector telescope mounted atop EQ-2 equatorial mounts. This old design (still in use today) instilled hinge plates used to connect the two halves of the cradle to allow the top section to be swung in a manner that eliminated damage to the tubes finish. The rounded ends of each hinge plate was shaped using a bench grinder. I will post another picture of the finished pieces once they are done.
Mel
--------------------
Clear Skies, Forever!
The Vega Sky Center
10" (254mm) F/5.65 Home Built Fork Mounted Newtonian Reflector
5" (127mm) F/9.4 Home Built Refractor (under construction)
3.5" (90mm) F/11.1 "Vixen-Spec Modified" Konus Refractor
3.1" (80mm) F/6 Scopos ED APO Refractor
4.5" (114mm) F/8 Tasco 11te-5 Newtonian (under restoration)
2.4" (60mm) F/16.7 Tasco 7te-5 Refractor
2.4" (60mm) F/15 Jason Discoverer 313 Refractor
http://www.vega-sky-center.com
|
allanovercast
member
Reged: 08/02/07
Posts: 55
Loc: Billings, MT
|
|
Looks good Mel, I have been busy with the day job and have not had any extra time to play. I plan on painting (priming) tonight and get a coat on tomorrow before I am off on a 9 day off-shore trip. Work trumps play, but making slow progress.
Allan Overcast
Cloudy Skies Observatory
10" Meade RCX-400
80mm Homeade Refractor
Canon 350D Modified Camera
Pier-Tech 2 Pier
8' Exploradome
http://www.cloudyskies.org
--------------------
Allan Overcast
Cloudy Skies Observatory
10" Meade RCX-400
80mm Homeade Refractor
1277mm Homeade Refractor
Canon 350D Modified Camera
Q-Guider Camera
Pier-Tech 2 Pier
8' Exploradome
http://www.cloudyskies.org
|
dawsonian2000
professor emeritus
Reged: 07/26/06
Posts: 552
Loc: Riverview, FL, USA
|
|
I understand how little time there is for play too, Allan. I barely found the time to do the work on the cradle.
BTW - Prior to priming, how will you prep your tube?
Hope you will have a great trip.
Mel
--------------------
Clear Skies, Forever!
The Vega Sky Center
10" (254mm) F/5.65 Home Built Fork Mounted Newtonian Reflector
5" (127mm) F/9.4 Home Built Refractor (under construction)
3.5" (90mm) F/11.1 "Vixen-Spec Modified" Konus Refractor
3.1" (80mm) F/6 Scopos ED APO Refractor
4.5" (114mm) F/8 Tasco 11te-5 Newtonian (under restoration)
2.4" (60mm) F/16.7 Tasco 7te-5 Refractor
2.4" (60mm) F/15 Jason Discoverer 313 Refractor
http://www.vega-sky-center.com
|
dawsonian2000
professor emeritus
Reged: 07/26/06
Posts: 552
Loc: Riverview, FL, USA
|
|
Over the weekend I got the opportunity to cut my tube using the method that Ron (rboe) suggested on CN (Thanks Ron!). I basically used a sheet of thick paper with a straight edge and wrapped it around the tube to establish a precise perpendicular line to its circumference. Then, using a 127mm hole saw I cut a circle in a piece of plywood. The plywood piece was then slid onto the tube up to the line I drew allowing for the thickness of the hacksaw blade, and then polyurethane glue applied to the opposite side of the plywood to secure it.
The following morning the glue had dried completely. I next removed the hacksaw blade from its handle and with its side pressed against the plywood as a guide began slowly etching a groove around the entire circumference of the tube where I had drawn the line. Once the groove was made, I used a hammer to carefully dislodge the plywood from the tube. Then I reassembled my hacksaw and began slowly and methodically sawing my way around the tube. Once separated from the unwanted section, I used several files to remove the burrs. I must say, the completed job turned out fantastic! True all the way around the tube. The results truly exceeded expectation. Totally exceptional!
BTW - I also got the chance to mount the objective and focuser to the tube for a preliminary test to see if the tube length was sufficient. Turn out great! I was able to focus on a star using a 1.25" TeleVue 20mm Plossl eyepiece loaded into my 2" star diagonal and had plenty of inward and outward focuser travel to boot after attaining a focus! I did not get the chance to test one of my 2" oculars, but I think I will be good nevertheless.
I will have to do as Allan did and sand the cell to allow the tube to be inserted into the cell completely. Initially, I could have sworn that I would have been able to do so without sanding. Just one of those poor assessments.
Well, I did run into another issue with my focuser too, which can be rectified. It turned out that the UHMW adhesive "Slick Tape" I used to replace the guides in the focuser is too thick, which caused the focuser tube to be non-concentric. The thinner tape I will use should take care of this issue. I will post images to help clarify the tube cutting procedures I used later.
P.S. Hey Allan! Hope you and yours are having a great time on your cruise. Bon Voyage!
Mel
--------------------
Clear Skies, Forever!
The Vega Sky Center
10" (254mm) F/5.65 Home Built Fork Mounted Newtonian Reflector
5" (127mm) F/9.4 Home Built Refractor (under construction)
3.5" (90mm) F/11.1 "Vixen-Spec Modified" Konus Refractor
3.1" (80mm) F/6 Scopos ED APO Refractor
4.5" (114mm) F/8 Tasco 11te-5 Newtonian (under restoration)
2.4" (60mm) F/16.7 Tasco 7te-5 Refractor
2.4" (60mm) F/15 Jason Discoverer 313 Refractor
http://www.vega-sky-center.com
|
dawsonian2000
professor emeritus
Reged: 07/26/06
Posts: 552
Loc: Riverview, FL, USA
|
|
"Tube Cutting Process"
Once I determined the tube length, a line was drawn around the circumference of the tube, and a piece of plywood with a hole the same diameter was precisely slid up to the line. Spinning the tube with the plywood piece in place verified correct placement and alignment.
Mel
--------------------
Clear Skies, Forever!
The Vega Sky Center
10" (254mm) F/5.65 Home Built Fork Mounted Newtonian Reflector
5" (127mm) F/9.4 Home Built Refractor (under construction)
3.5" (90mm) F/11.1 "Vixen-Spec Modified" Konus Refractor
3.1" (80mm) F/6 Scopos ED APO Refractor
4.5" (114mm) F/8 Tasco 11te-5 Newtonian (under restoration)
2.4" (60mm) F/16.7 Tasco 7te-5 Refractor
2.4" (60mm) F/15 Jason Discoverer 313 Refractor
http://www.vega-sky-center.com
|
dawsonian2000
professor emeritus
Reged: 07/26/06
Posts: 552
Loc: Riverview, FL, USA
|
|
"Tube Cutting Process"
Once accurate positioning of the plywood piece was established on the tube, I applied Polyurethane glue to the opposite side of the plywood where the tube and plywood made contact. I was very careful not to disturb the alignment.
Mel
--------------------
Clear Skies, Forever!
The Vega Sky Center
10" (254mm) F/5.65 Home Built Fork Mounted Newtonian Reflector
5" (127mm) F/9.4 Home Built Refractor (under construction)
3.5" (90mm) F/11.1 "Vixen-Spec Modified" Konus Refractor
3.1" (80mm) F/6 Scopos ED APO Refractor
4.5" (114mm) F/8 Tasco 11te-5 Newtonian (under restoration)
2.4" (60mm) F/16.7 Tasco 7te-5 Refractor
2.4" (60mm) F/15 Jason Discoverer 313 Refractor
http://www.vega-sky-center.com
|
dawsonian2000
professor emeritus
Reged: 07/26/06
Posts: 552
Loc: Riverview, FL, USA
|
|
"Tube Cutting Process"
Overnight, the Polyurethane glue hardened and the next morning I began sawing a groove around the circumference of the tube while using the glued on plywood as a guide.
Mel
--------------------
Clear Skies, Forever!
The Vega Sky Center
10" (254mm) F/5.65 Home Built Fork Mounted Newtonian Reflector
5" (127mm) F/9.4 Home Built Refractor (under construction)
3.5" (90mm) F/11.1 "Vixen-Spec Modified" Konus Refractor
3.1" (80mm) F/6 Scopos ED APO Refractor
4.5" (114mm) F/8 Tasco 11te-5 Newtonian (under restoration)
2.4" (60mm) F/16.7 Tasco 7te-5 Refractor
2.4" (60mm) F/15 Jason Discoverer 313 Refractor
http://www.vega-sky-center.com
|
dawsonian2000
professor emeritus
Reged: 07/26/06
Posts: 552
Loc: Riverview, FL, USA
|
|
"Tube Cutting Process"
With the groove established, the plywood was removed with a few taps of a hammer.
Mel
--------------------
Clear Skies, Forever!
The Vega Sky Center
10" (254mm) F/5.65 Home Built Fork Mounted Newtonian Reflector
5" (127mm) F/9.4 Home Built Refractor (under construction)
3.5" (90mm) F/11.1 "Vixen-Spec Modified" Konus Refractor
3.1" (80mm) F/6 Scopos ED APO Refractor
4.5" (114mm) F/8 Tasco 11te-5 Newtonian (under restoration)
2.4" (60mm) F/16.7 Tasco 7te-5 Refractor
2.4" (60mm) F/15 Jason Discoverer 313 Refractor
http://www.vega-sky-center.com
|
dawsonian2000
professor emeritus
Reged: 07/26/06
Posts: 552
Loc: Riverview, FL, USA
|
|
"Tube Cutting Process"
Close-up of the groove after the plywood was removed.
Mel
--------------------
Clear Skies, Forever!
The Vega Sky Center
10" (254mm) F/5.65 Home Built Fork Mounted Newtonian Reflector
5" (127mm) F/9.4 Home Built Refractor (under construction)
3.5" (90mm) F/11.1 "Vixen-Spec Modified" Konus Refractor
3.1" (80mm) F/6 Scopos ED APO Refractor
4.5" (114mm) F/8 Tasco 11te-5 Newtonian (under restoration)
2.4" (60mm) F/16.7 Tasco 7te-5 Refractor
2.4" (60mm) F/15 Jason Discoverer 313 Refractor
http://www.vega-sky-center.com
|
dawsonian2000
professor emeritus
Reged: 07/26/06
Posts: 552
Loc: Riverview, FL, USA
|
|
"Tube Cutting Process"
With the hacksaw reassembled, I began rotating and slowing sawing around the tube using the groove, which aligned the blade precisely.
Mel
--------------------
Clear Skies, Forever!
The Vega Sky Center
10" (254mm) F/5.65 Home Built Fork Mounted Newtonian Reflector
5" (127mm) F/9.4 Home Built Refractor (under construction)
3.5" (90mm) F/11.1 "Vixen-Spec Modified" Konus Refractor
3.1" (80mm) F/6 Scopos ED APO Refractor
4.5" (114mm) F/8 Tasco 11te-5 Newtonian (under restoration)
2.4" (60mm) F/16.7 Tasco 7te-5 Refractor
2.4" (60mm) F/15 Jason Discoverer 313 Refractor
http://www.vega-sky-center.com
|
dawsonian2000
professor emeritus
Reged: 07/26/06
Posts: 552
Loc: Riverview, FL, USA
|
|
"Tube Cutting Process"
After meticulous cutting, I finally made it through various points around the tube eventually breaking the entire circumference.
Mel
--------------------
Clear Skies, Forever!
The Vega Sky Center
10" (254mm) F/5.65 Home Built Fork Mounted Newtonian Reflector
5" (127mm) F/9.4 Home Built Refractor (under construction)
3.5" (90mm) F/11.1 "Vixen-Spec Modified" Konus Refractor
3.1" (80mm) F/6 Scopos ED APO Refractor
4.5" (114mm) F/8 Tasco 11te-5 Newtonian (under restoration)
2.4" (60mm) F/16.7 Tasco 7te-5 Refractor
2.4" (60mm) F/15 Jason Discoverer 313 Refractor
http://www.vega-sky-center.com
|
dawsonian2000
professor emeritus
Reged: 07/26/06
Posts: 552
Loc: Riverview, FL, USA
|
|
"Tube Cutting Process"
Burrs were removed with a set of files.
Mel
--------------------
Clear Skies, Forever!
The Vega Sky Center
10" (254mm) F/5.65 Home Built Fork Mounted Newtonian Reflector
5" (127mm) F/9.4 Home Built Refractor (under construction)
3.5" (90mm) F/11.1 "Vixen-Spec Modified" Konus Refractor
3.1" (80mm) F/6 Scopos ED APO Refractor
4.5" (114mm) F/8 Tasco 11te-5 Newtonian (under restoration)
2.4" (60mm) F/16.7 Tasco 7te-5 Refractor
2.4" (60mm) F/15 Jason Discoverer 313 Refractor
http://www.vega-sky-center.com
|
dawsonian2000
professor emeritus
Reged: 07/26/06
Posts: 552
Loc: Riverview, FL, USA
|
|
"Tube Cutting Process"
Tube cutting process complete!
Mel
--------------------
Clear Skies, Forever!
The Vega Sky Center
10" (254mm) F/5.65 Home Built Fork Mounted Newtonian Reflector
5" (127mm) F/9.4 Home Built Refractor (under construction)
3.5" (90mm) F/11.1 "Vixen-Spec Modified" Konus Refractor
3.1" (80mm) F/6 Scopos ED APO Refractor
4.5" (114mm) F/8 Tasco 11te-5 Newtonian (under restoration)
2.4" (60mm) F/16.7 Tasco 7te-5 Refractor
2.4" (60mm) F/15 Jason Discoverer 313 Refractor
http://www.vega-sky-center.com
|
allanovercast
member
Reged: 08/02/07
Posts: 55
Loc: Billings, MT
|
|
Previous
Index
Next
Threaded
Edit
Reply
Quote
[Re: