jstephany
member
Reged: 12/17/07
Posts: 63
Loc: Madison WI
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Hi,
I know at some point I saw an article on homebuilding a collimating site tube using plumbing parts. The specific article had a drawing of a template to use to place the crosshair threads. it might have been a mag article? Anyone know where I can find the article/link/what have you?
THanks!
John
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John
10" Orion xt classic dob
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Mirzam
member
Reged: 04/01/08
Posts: 20
Loc: Lovettsville, VA
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Hi John,
I have used a plastic 35 mm film canister with a hole drilled at the center of the bottom (where there is a small dimple left over from the plastic molding process). These have the same OD as a 1.25 " eyepiece.
Jim
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okiestarman56
super member
Reged: 04/10/08
Posts: 217
Loc: 36.9'33" N 95.23'29" W
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One place to find an article like that is in Phil Harringtons Star Ware book second edition page 194
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305mm f/5 GSO 12" DSO
114mm f/7.8 Tasco 4.5" Red Tube
80mm f/15 Sears 3.1" Refractor #412.44540
60mm f/15 Sears 2.3" Refractor #4 6305-A
60mm f/15 Sears 2.3" Refractor #4451
Plenty of EPs? .965 to 2"
2 LPI's
Home made Denver chair
3-7'x10' light panels
yada yada yada
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wojo
super member
Reged: 09/28/07
Posts: 132
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A collimation article by NILS OLAF CARLSON (sorry NILS if I MISSPELLED} HAS A SECTION ON HOW TO BUILD YOUR OWN SIGHT TUBE , CHESHIRE EYEPIECE,ETC AND ALSO A GOOD COLLIMATION ARTICLE. SEARCH THE ARCHIVES AND YOU WILL RUN ACROSS IT.OR SOMEONE ELSE WILL CHIME IN WITH THE WEB PAGE.
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Darenwh
professor emeritus
Reged: 05/11/06
Posts: 617
Loc: Saint Francis, WI
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Found links to Nils site on colmination. It is excellent. Good job Nils.
FAQ about Collimating a Newtonian telescope.
The Do-It-Yourself section:
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Daren
St. Francis, WI
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jstephany
member
Reged: 12/17/07
Posts: 63
Loc: Madison WI
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I should have mentioned that I already did a search and found the Olof article. The one I'm looking for was different, showed how to make one with a chrome 1 1/4" drain tube. It had a diagram/ template to use to lay out the cross hairs. No big deal if no one knows of it. THanks!
John
PS. Daren, where is Saint Francis? I'm in Madison.
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John
10" Orion xt classic dob
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jstephany
member
Reged: 12/17/07
Posts: 63
Loc: Madison WI
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Eureka!
I found it. It's at Phil Harrington's sight for the "Starware" book. It's in the "extras" section for the book. Philharrington.net go to Starware book, and you have to have a copy of the book to get access to the extras.
Thanks anyway!
John
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John
10" Orion xt classic dob
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David L
super member
Reged: 11/12/07
Posts: 135
Loc: Lee County Iowa
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From where I used to work, I saved a bunch of plastic tubes with a 1.25 inch diameter. I took a small piece of Corian plastic, drilled it out to 1.25 inches with a Forstner bit, and leaving it clamped in the drill press, drilled a small hole, the bit being guided by the dimple left by the Forstner.
Dave
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8.5 X 44 Swift Audubon binoculars
100 mm semi-apo triplet PVC spotting scope
6 inch F8 dobsonian
10 inch F4.5 dobsonian
2 2-cylinder equatorial platforms, 2-roller direct drive
22X100 Oberwerk binoculars (just received)
6" F6.5 Antares refractor
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okiestarman56
super member
Reged: 04/10/08
Posts: 217
Loc: 36.9'33" N 95.23'29" W
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jstephany-----try "Binocular" at phils site
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305mm f/5 GSO 12" DSO
114mm f/7.8 Tasco 4.5" Red Tube
80mm f/15 Sears 3.1" Refractor #412.44540
60mm f/15 Sears 2.3" Refractor #4 6305-A
60mm f/15 Sears 2.3" Refractor #4451
Plenty of EPs? .965 to 2"
2 LPI's
Home made Denver chair
3-7'x10' light panels
yada yada yada
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Show-me
newbie
Reged: 06/08/08
Posts: 3
Loc: Spring Creek, MO
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Adam Perkins site has very good instructions, unfortunately no pics:
http://www.starastronomy.org/TelescopeMaking/perkins.html
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Orion SkyView 4.5
Pentax 7x50 pcf wp
NU-B
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wojo
super member
Reged: 09/28/07
Posts: 132
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JOHN...... If you are looking for how to locate the position for the cross hairs, heres how I do it. Take a index card that will wrap around the tube ,carefully align edge of paper with edge of tube, cut paper so ends meet, in other words, 1 wrap around tube . Fold in half , fold halves in half. re wrap around tube and mark tube at folds. The fussier you are about getting it accurate the better. Once you have your cross hairs in place you can test your work by inserting tube in focuser and rotating it 1/4 turn at a time, if intersection of cross hairs stay in same place you have a winner! ..... HOPE this is what your looking for.... WOJO
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tjmck
super member
Reged: 10/06/07
Posts: 113
Loc: Winnipeg, Manitoba, Canada
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John,
I have also used the method WOJO describes.
Thought I would add to the thread that for a 2" focuser, built in vacuum systems use PVC pipe that has a 2" outside diameter. You may have to check a few pieces to find one that works as the dimensional quality control is not all that good. The good news is that most vacuum installation places / contractors have off cuts that they will normally give you once you educate them what you will use it for.
tjmck
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10" F4.7 Dob - home built
Meade ETX-125PE, 1247 Focuser, DSI Colour
Pentax 20x60 PCF WPII w/ home made parallelogram mount
Numerous eyepieces (don't we all have them?)
Home made accessories: power center, dew controller, observing chair, Hartmann mask, dew shields, counter weights, cases and storage solutions.
Inspiration for most modifications and home made items from CN posts!
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Tom Andrews
professor emeritus
Reged: 01/25/07
Posts: 563
Loc: Homebase - Albuquerque, NM; c...
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Here's a picture of mine just for the heck of it.
By the way, I used a micrometer for marking where to put the crosshairs which worked great if you have one or access to one.
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Tom
The Secret To Life:
Focus on what you have, not on what you don't;
Focus on what you can do, not on what you can't.
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Tom Andrews
professor emeritus
Reged: 01/25/07
Posts: 563
Loc: Homebase - Albuquerque, NM; c...
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The cap is a 35mm film cannister top with a pin hole in the center.
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Tom
The Secret To Life:
Focus on what you have, not on what you don't;
Focus on what you can do, not on what you can't.
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Biff
Carpal Tunnel
Reged: 09/04/05
Posts: 2227
Loc: Courtice, Ontario
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Mine is very similar to Toms. I got a 1.25" aluminum tube from Home Depot that is actually exactly 1.25" O.D. and I found that the lid for a can of spraypaint pressed on the end nicely (you know the inner tube part that's on most spraypaint can lids). Then I just trimmed off the excess and made a hole in the center. Works perfectly! You can drill some small holes and epoxy in some small wire cross hairs near the end if you want to but for aligning the mirrors I made a laser out of the same tube and a laser pointer. Not nearly as fancy as some out there but it's all in the collimation for how good any laser tool is. I use that align the secondary then put that tool in an old barlow to align the primary. It goes pretty quick and is surprisingly accurate.
I use those two tools plus the barlow 99% of the time despite having a full compliment of Catseye tools... let the flaming begin LOL.
[edit]
I just wanted to add that using the two homemade tools gets me pretty darn close as confirmed by my autocollimator, certainly close enough for my f/6.
[/edit]
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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
Edited by Biff (07/05/08 02:40 PM)
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