· Get a Cloudy Nights T-Shirt · Submit a Review / Article    Click here if you are having trouble logging into the forums Privacy Policy | Please read our Terms of Service | Signup and Troubleshooting FAQ | Problems? PM a Red or a Green Gu.... uh, User   You are not logged in. [Login] Forum Archives · Entrance · Main Index · Search · New user · Who's Online FAQ · Calendar Equipment Discussions >> ATM, Optics and DIY Forum Previous   Index   Next   Threaded   Pages: 1 | 2 | 3 | (show all) neo professor emeritus Reged: 02/12/08 Posts: 724 Loc: Iasi, Romania Uberfractor       #3324621 - 09/09/09 06:08 PM Attachment (130 downloads) Edit   Reply   Quote Quick Reply   Hi everyone! Here's my little big summer project which is still an on going process to redo a small refractor I have. The scope is based on a 70mm f/6 Rodenstock Rotelar lens found on ebay at West Coast Camera if I remmember corectly. Very good lens, pretty much an Apo, some time ago I did a ronchi test on it and came out very nice. As for the fabrication itself I tried to keep things simple and I used usual materials found on my local hardware store. So for the tube I used a 110mm PVC pipe reinforced with plywood rings treated with epoxy to seal them from moisture and for stiffness. The lens had initially an aluminum ring which I used now to make the push&pull collimation system. The focuser it's all custom made Crayford style fitted inside the OTA because the focusing distance is short, in fact quite critical so no room for a classic one. -------------------- Russian 15x50 binos Home made 8" f/5 Newton on eq mount Home made 70mm f/6 (Rodenstock Rotelar lens) Apo refractor www.astronomy.ro Post Extras:       neo professor emeritus Reged: 02/12/08 Posts: 724 Loc: Iasi, Romania Re: Uberfractor [Re: neo]       #3324624 - 09/09/09 06:09 PM Attachment (77 downloads) Edit   Reply   Quote Quick Reply   The collimation ring seats on a thick plywood ring. -------------------- Russian 15x50 binos Home made 8" f/5 Newton on eq mount Home made 70mm f/6 (Rodenstock Rotelar lens) Apo refractor www.astronomy.ro Edited by neo (09/09/09 06:20 PM) Post Extras:       neo professor emeritus Reged: 02/12/08 Posts: 724 Loc: Iasi, Romania Re: Uberfractor [Re: neo]       #3324631 - 09/09/09 06:11 PM Attachment (52 downloads) Edit   Reply   Quote Quick Reply   Collimation screws... -------------------- Russian 15x50 binos Home made 8" f/5 Newton on eq mount Home made 70mm f/6 (Rodenstock Rotelar lens) Apo refractor www.astronomy.ro Post Extras:       neo professor emeritus Reged: 02/12/08 Posts: 724 Loc: Iasi, Romania Re: Uberfractor [Re: neo]       #3324642 - 09/09/09 06:16 PM Attachment (72 downloads) Edit   Reply   Quote Quick Reply   The focuser was pretty tricky cause without special tools was quiet difficult tu allign the four bearings to get an even contact with the focuser's tube. So VIVA epoxy -------------------- Russian 15x50 binos Home made 8" f/5 Newton on eq mount Home made 70mm f/6 (Rodenstock Rotelar lens) Apo refractor www.astronomy.ro Post Extras:       neo professor emeritus Reged: 02/12/08 Posts: 724 Loc: Iasi, Romania Re: Uberfractor [Re: neo]       #3324649 - 09/09/09 06:18 PM Attachment (61 downloads) Edit   Reply   Quote Quick Reply   ... -------------------- Russian 15x50 binos Home made 8" f/5 Newton on eq mount Home made 70mm f/6 (Rodenstock Rotelar lens) Apo refractor www.astronomy.ro Post Extras:       neo professor emeritus Reged: 02/12/08 Posts: 724 Loc: Iasi, Romania Re: Uberfractor [Re: neo]       #3324664 - 09/09/09 06:25 PM Attachment (63 downloads) Edit   Reply   Quote Quick Reply   Focuser...still some details to finish, like the screw that press the brass rod over the focuser's tube and the lock screw. -------------------- Russian 15x50 binos Home made 8" f/5 Newton on eq mount Home made 70mm f/6 (Rodenstock Rotelar lens) Apo refractor www.astronomy.ro Post Extras:       rwiederrich Goldfinger Reged: 11/17/05 Posts: 8681 Loc: Bremerton Washington Re: Uberfractor [Re: neo]       #3324713 - 09/09/09 06:54 PM Edit   Reply   Quote Quick Reply   Well Neo....that is pretty nifty. I like your application of epoxy.....It's tough stuff. How does the little guy take magnification? Rob -------------------- www.goldmtobservingcenter.com A great place for amateur astronomers, and ATM's to come and enjoy their hobby. http://tech.groups.yahoo.com/group/HomemadeRefractorTelescopes/ My homemade refractor group. www.vimeo.com/6014031 Post Extras:       neo professor emeritus Reged: 02/12/08 Posts: 724 Loc: Iasi, Romania Re: Uberfractor [Re: rwiederrich]       #3324759 - 09/09/09 07:17 PM Edit   Reply   Quote Quick Reply   Thanks buddy! Fun stuff epoxy. The magnification goes amazingly well for a photo lens ( assuming that is a photo lens..I'm not very sure) about twice its diameter if it's very well collimated..so about 140X. But I expect that its true strength stands on astroimaging cause it has a super flat field. To bad i don't have one of those fancy SBIGs to take some pics. -------------------- Russian 15x50 binos Home made 8" f/5 Newton on eq mount Home made 70mm f/6 (Rodenstock Rotelar lens) Apo refractor www.astronomy.ro Edited by neo (09/09/09 07:19 PM) Post Extras:       magic612 Pooh-Bah Reged: 09/30/08 Posts: 1035 Loc: Somewhere south of Chicago, IL Re: Uberfractor [Re: neo]       #3325117 - 09/09/09 10:47 PM Edit   Reply   Quote Quick Reply   neo - that looks great! And I'm with you on the epoxy thing; that's great stuff. -------------------- - 10" Orion Dob, 127mm f/9 refractor, 127mm f/4.4 refractor, 5" f/8 Dob (homemade), 90mm f/10 Orion refractor, 114mm f/8 reflector, Tasco 11TE-5 reflector, 60mm Sears 6333-A refractor - Orion Vista 10x50s, Sears #6207 7x35's, Jason Statesman 7x35's Yes, I'm addicted to telescopes and binoculars. I am getting help. Every time I look at the heavens, it helps. http://www.eyesonthesky.com Post Extras:       neo professor emeritus Reged: 02/12/08 Posts: 724 Loc: Iasi, Romania Re: Uberfractor [Re: magic612]       #3325480 - 09/10/09 06:43 AM Edit   Reply   Quote Quick Reply   Thanx magic I've just learned something new today...a fellow ATM guy from our local astronomy forum suggested mixing aluminum filings (or other powders...I guess) with epoxy. The new composite material could be poured in molds to get different parts. A very exiting ideea anyway. -------------------- Russian 15x50 binos Home made 8" f/5 Newton on eq mount Home made 70mm f/6 (Rodenstock Rotelar lens) Apo refractor www.astronomy.ro Post Extras:       Owen professor emeritus Reged: 06/21/07 Posts: 519 Re: Uberfractor [Re: neo]       #3325623 - 09/10/09 09:14 AM Edit   Reply   Quote Quick Reply   I know guys who have been doing this with diamond powder. The resulting part is 'very' durable.... Owen Post Extras:       neo professor emeritus Reged: 02/12/08 Posts: 724 Loc: Iasi, Romania Re: Uberfractor [Re: Owen]       #3335786 - 09/15/09 05:14 PM Attachment (49 downloads) Edit   Reply   Quote Quick Reply   A small update: I've put up some detailes on the focuser like the locking screw and the tension screw. The focusing axle being on ball bearings I added a small teflon piece from a CD-rom to act as a break. Also I prepared the thumbscrews made out from aluminum potentiometer knobs which will be screwed on the brass axel. I plan to add a planetary reduction knob..sort of ... well...in fact a ball bearing atached to the thumbscrew from the right side which will be tightened against a rubber washer causing some friction, so when I turn the ball bearing's outer ring (with another knob on top) a few times the focusing axle turns ones. Ah...I guess you got the idea -------------------- Russian 15x50 binos Home made 8" f/5 Newton on eq mount Home made 70mm f/6 (Rodenstock Rotelar lens) Apo refractor www.astronomy.ro Post Extras:       neo professor emeritus Reged: 02/12/08 Posts: 724 Loc: Iasi, Romania Re: Uberfractor [Re: neo]       #3335788 - 09/15/09 05:15 PM Attachment (31 downloads) Edit   Reply   Quote Quick Reply   The focusing knobs -------------------- Russian 15x50 binos Home made 8" f/5 Newton on eq mount Home made 70mm f/6 (Rodenstock Rotelar lens) Apo refractor www.astronomy.ro Post Extras:       neo professor emeritus Reged: 02/12/08 Posts: 724 Loc: Iasi, Romania Re: Uberfractor [Re: neo]       #3337713 - 09/16/09 04:50 PM Attachment (40 downloads) Edit   Reply   Quote Quick Reply   Today I've assembled the focuser, mounted the thumbscrews after I threded the both ends of the brass axle. Also I experimented some more with my improvised planetary gear which....shamefully I realized that the principle is a bit wrong. After some research I've learned that I could build such a gizmo with 3 small ball bearings so I'll see how it turns out...I hope I still have some tiny bearings. Anyway ..pictures...so here's the focuser.. -------------------- Russian 15x50 binos Home made 8" f/5 Newton on eq mount Home made 70mm f/6 (Rodenstock Rotelar lens) Apo refractor www.astronomy.ro Edited by neo (09/16/09 04:51 PM) Post Extras:       neo professor emeritus Reged: 02/12/08 Posts: 724 Loc: Iasi, Romania Re: Uberfractor [Re: neo]       #3337718 - 09/16/09 04:51 PM Attachment (29 downloads) Edit   Reply   Quote Quick Reply   .... -------------------- Russian 15x50 binos Home made 8" f/5 Newton on eq mount Home made 70mm f/6 (Rodenstock Rotelar lens) Apo refractor www.astronomy.ro Post Extras:       neo professor emeritus Reged: 02/12/08 Posts: 724 Loc: Iasi, Romania Re: Uberfractor [Re: neo]       #3337722 - 09/16/09 04:53 PM Attachment (45 downloads) Edit   Reply   Quote Quick Reply   Just a quick assemble of the scope. -------------------- Russian 15x50 binos Home made 8" f/5 Newton on eq mount Home made 70mm f/6 (Rodenstock Rotelar lens) Apo refractor www.astronomy.ro Post Extras:       neo professor emeritus Reged: 02/12/08 Posts: 724 Loc: Iasi, Romania Re: Uberfractor [Re: neo]       #3337723 - 09/16/09 04:54 PM Attachment (35 downloads) Edit   Reply   Quote Quick Reply   .. -------------------- Russian 15x50 binos Home made 8" f/5 Newton on eq mount Home made 70mm f/6 (Rodenstock Rotelar lens) Apo refractor www.astronomy.ro Post Extras:       David Castillo scholastic sledgehammer Reged: 09/09/06 Posts: 953 Loc: Carmel Valley, Ca Re: Uberfractor [Re: neo]       #3337868 - 09/16/09 06:12 PM Edit   Reply   Quote Quick Reply   That is SWEET, eo. I like your idea of rigging a vernier reduction knob- puts it up there on another level ---- Dave Post Extras:       neo professor emeritus Reged: 02/12/08 Posts: 724 Loc: Iasi, Romania Re: Uberfractor [Re: David Castillo]       #3339663 - 09/17/09 02:56 PM Attachment (34 downloads) Edit   Reply   Quote Quick Reply   Thanx Dave ! I've found (finally) a Chinese site where was explained with tons of pictures the design of those vernier reduction knobs from GSO, I guess. So now everything is clear; still I need to try to build it with the materials in hand. http://bbs.astron.ac.cn/thread-54988-1-3.html Here's some paint job I've done today, in fact only the primer, tomorrow I have to buy a paint can to finish. -------------------- Russian 15x50 binos Home made 8" f/5 Newton on eq mount Home made 70mm f/6 (Rodenstock Rotelar lens) Apo refractor www.astronomy.ro Post Extras:       neo professor emeritus Reged: 02/12/08 Posts: 724 Loc: Iasi, Romania Re: Uberfractor [Re: neo]       #3341813 - 09/18/09 05:24 PM Attachment (46 downloads) Edit   Reply   Quote Quick Reply   Today I've received from my local work shop the focusers tube after some adjustments on lathe and now it's all nice and shiny ( good old table leg ). I've drilled three holes at 120 degrees and threaded them to be sure it holds my 2" Meade UHTC diagonal which is surprisingly heavy. Because the tube is quiet thinn and I can't grind it flat for more grip with the focusing axle, I cut a narrow piece of fine sand paper (320#) and glued it with a double sided duct tape on the fousers tube. This way the axle will hold tight the focusing tube even with a heavy load. -------------------- Russian 15x50 binos Home made 8" f/5 Newton on eq mount Home made 70mm f/6 (Rodenstock Rotelar lens) Apo refractor www.astronomy.ro Post Extras:       Pages: 1 | 2 | 3 | (show all) Previous   Index   Next   Threaded   Extra information 16 registered and 6 anonymous users are browsing this forum. Moderator:  Don W, Mike I. 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