Edited by Matej, 11 September 2020 - 12:12 PM.
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Posted 11 September 2020 - 12:10 PM
Edited by Matej, 11 September 2020 - 12:12 PM.
Posted 14 September 2020 - 06:57 AM
this one took 16 years to complete, but last weekend I finally managed to get it assembled: a 125mm f/8 doublet refractor.
The tube is entirely made of wood: small strips of pine, glued together to form a perfect cylinder.
The baffle is made out of airplane plywood.
The rest is a mix of different DIY techniques: laser cutting for the internal baffles, 3D printing for the lens cell and the focus adapter, CNC milling of different flanges, tube rings and mounting plate, and of course good old fashioned planing, sanding and drilling.
There is still some work left, like varnishing the tube and finalising the baffle. But at least I could have first light yesterday on the sun (she is boring these days...) and perform a star test last evening. Stars looks nice, just need some fine tuning on the collimation.
Oh well, just a few more years to go...
Edited by jvrsluys, 14 September 2020 - 06:57 AM.
Posted 14 September 2020 - 05:41 PM
Homemade 6" f/8 Newtonian Reflector out of concrete form tubing and weather sealed with fiberglass and resin, coated with oil-based paint. The mount is a homemade tripod mount using schematics from Vega Sky Center with some personal liberties taken, using a combination of redwood, pine and hickory, with the base and cradle made from 3/4", 1-1/2" and 2" cabinet grade plywood. The GEM is made of 1-1/4" pipe fittings with PVC bushings bored to allow PTFE sleeve bearings to accommodate the 3/4" pipe.
Awesome job, Brian! I am truly appreciative that you used my design and added features to make it your own! It makes me so amazed that the North Star II field tripod designs are being utilized by others within the ATM community. I could not be any happier!
I see that you designed your tripod for your homemade 6" f/8 Newtonian and pipe GEM. And they look fantastic sitting atop your tripod! Congratulations!!!
Well, strangely enough, I just completing building a 10" f/4.7 Newtonian for my friend, brother and colleague Gary Barabino. I just completed it on Saturday 09/12/2020, which I built and gifted to him while he was visiting. And it is seen here in this photo with Gary looking through it sitting atop the actual North Star II Field Tripod I created and showcased on the Vega Sky Center website; for which you designed yours from!
Congrats and thanks again for sharing your wonderful tripod to the astronomical community and for using my design! What a blessing!
If possible, please send me some photos and some details on its construction. As time permits, I would love to feature it on the VSC website. It can only be inspiring to other amateurs looking to build a tripod of their own.
Thanks a million!!!
Edited by dawsonian2000, 15 September 2020 - 05:11 PM.
Posted 24 September 2020 - 11:11 AM
An update from post #1437. I have been constantly tweaking my ATM 10" f/6 Dob. I bought an astrozap light shield, which I had to modify for my OTA diameter. Simple enough to remove the velco stitching, trim the webbing as needed and sew the velcro back on. Added velcro on the Dob mount as well to accommodate homemade fan controller, dew controller, and those little silicone cable organizers to keep all the cables stay out of the way. Fans are typical 80mm computer fans that I soldered male RCA cable ends on for convenience. Fans are held on the OTA by you guess it velcro, with PU foam sandwiched in between to dampen any possible vibrations. Has worked great so far, but I may be adding more fans or a larger fan behind the mirror. The rear fan is velcro'd onto a thin piece of plywood that has three small cleats on it. PU foam is sandwiched between the fan plate and the OTA. Cheap elastic hair bands go from the OTA and wrap around the cleats to secure it in place. Also had a custom sized set of Scope Totes made from the Astronomy Shoppe to help move the OTA. They have been a huge improvement over awkwardly grabbing either end of the OTA for transport.
It is a fun Dob to use! Just hoping for some nice seeing conditions as we approach the Mars opposition.
Edited by mfoose, 24 September 2020 - 11:14 AM.
Posted 24 September 2020 - 01:08 PM
"Can you provide a closeup pic of the fans?"
So I based my fan mounting after h2ologg's fans on his beautiful 12.5" f/10 Dob. In corresponding with him, he told me he used some 3M double stick tape to hold the foam and fans to the OTA. I am not sure what material his OTA is, but my OTA is a heavy duty craft paper tube from Yazoo Mills. It is like a heavy duty sonotube. I didn't want to use double stick tape because it could peel off the paint or a few layers of the tube if I wasn't careful. I also didn't want the foam and the fans permanently mounted on the OTA. I could easily see those getting bumped and destroyed when transporting. So I had to come up with a way to be able to remove everything from the OTA for storage and transport, but also strong enough to hold it on the OTA during use. Thinking about it, I decided that velcro brand squares with the adhesive back should be enough. They aren't super sticky where they peel up the paint if I had to remove them and they are sticky enough not to come undone after repetitive use. I tested it before hand with extra supplies I had. They even stick to the foam, though I used a lot of pressure and I am careful when I remove the foam and fans from the OTA after each session. When not in use I replace the foam and fans with holes covers, a cut out square of foam sheet that I put velcro on as well. They are super cheap at walmart. To start each session I simply unvelcro the hole covers and velcro the foam and fans over the holes.
The pictures detail how I did it. I used a hole saw to drill two holes right at the place where the mirror surface sits. This was before I painted everything. I then placed four velcro squares around the hole and the corresponding velcro on top sticky side up. I cut PU foam into squares that overlap the area they cover. I then cut a hole slightly smaller then 80mm into the middle of the foam squares. This was so the fans covered the holes completely and nothing could fall into the tube. With the foam squares cut to sized and a hole cut in the middle I simply aligned the hole in the OTA to the hole in the foam square and pressed it down so the sticky side up velcro would adhere to the foam. With the two foam squares over top of the holes I then prepped the fans. I used the same velcro sticky squares and placed them on the corners of the 80mm fans and trimmed off the overhang. I put 4 velcro sticky squares on top of the foam squares so the velcro on the fans and the velcro on top of the foam squares would hold. I even oriented the velcro on the OTA and on the fans so I could do without the foam sandwiched in-between them and just mount them directly if I desired. I also bought some cheap 80mm fan grill covers so debris couldn't fall onto the fans and then onto the mirrors surface. All this to eliminate potential fan vibrations.
For the rear fan, I cut a circle out of a thin piece of plywood and then cut an 80mm hole out of the middle of that for the fan. I used the same velcro squares to mount the fan to the rear plate. This way I can easily switch the fan from blow air up the tube to pull air down in the tube by simply flipping its orientation. I cut a ring out of some thicker PU foam to sandwich the fan plate from the back of the tube. That foam ring is also held in place with those velcro stick squares. Those things have been very good to me lol. I also do have a fan grill cover for the rear fan, this one is different and uses a thin foam filter to keep dust from going up the OTA. However, I discovered that the filter prevents blocks a lot of air so I recently removed the filter from it.
Edited by mfoose, 24 September 2020 - 01:09 PM.
Posted 26 September 2020 - 03:50 PM
All right, enough discussion! Lets see some more scopes!
Posted 01 October 2020 - 07:56 AM
ok... got one.
Beamer lens, wiiiide field.
Image created with Stellarium - just to demonstrate the FOV!
Made a dew-shield for it in the meantime. However actually I never used it... was just a fun project.
Edited by GazingOli, 01 October 2020 - 02:30 PM.
Posted 01 October 2020 - 03:20 PM
I just cleaned up this thread of posts that were getting off track. Please use PMs or start separate threads if you are interested in any build-aspects or want to go into more detail about your projects.
Posted 10 October 2020 - 08:44 PM
I built this scope from a Coulter Optics set some 30+ years ago. It's an 8 inch f/20 Dall Kirkham. The tube was made with boat building veneers and WEST system epoxy.
Edited by stargazer1, 10 October 2020 - 08:51 PM.
Posted 13 October 2020 - 09:13 AM
Edited by Matej, 14 October 2020 - 05:36 AM.
Posted 15 October 2020 - 12:13 PM
I'm still a newbie ATM, and this is only my second build...but certain aspects turned out better than I anticipated; specifically with a DIY spider built from PVC flat stock and water pipe... The scope primary is an 8" f/8 (fl = 63.625") from UPCO Optics, made way-back-when(no real clue...1970?). The focuser is a Crayford style from Orion.
Posted 17 October 2020 - 08:32 AM
That scope must be great on the planets! Nice.
Posted 17 October 2020 - 01:36 PM
Interesting eyepiece arrangement.
The binocular telescope that was made by me and my friend almost 30 years ago. We were fourteen and fifteen. It still works as it used to those years ago. The two lenses were 56mm in diameter and of 800mm of focal length. The explanation below the pictures is however in Czech, so in case anyone of you were interested, I’m ready to translate it. Here are the pictures: https://refraktorian...nar_RAM_BD-800/
Posted 18 October 2020 - 05:22 AM
Posted 18 October 2020 - 06:08 AM
Posted 20 October 2020 - 11:11 AM
That is sexy. How did you build it?
Made an all new setup up for my TS 50mm apo lens.
Posted 20 October 2020 - 12:04 PM
That is sexy. How did you build it?
Posted 20 October 2020 - 01:34 PM
Very cool. I'll take one.
Really 2 different projects there. First was I cut an adapter to use a 2" helical focuser on an older willam optics dielectric diagonal. Second was to ditch the stock focuser, and cut a piece of carbon fiber tube to the right length for the body. I machined threaded rings for each side, attaching with screws and expoxy. I refinshed the stock dewshield, and went with a polished mixed with brushed finish throughout. Im not sure why, but the views are somehow marginally improved. Maybe better alignment, who knows.
Posted Today, 01:20 AM
Pretty scope. Looks like it is fairly light-weight, too. More photos?
It's about 25lb, so not terribly lightweight. The tube is somewhat overbuilt. I probably could have used one less layer of veneer. There are two layers of cedar tilted 30 degrees from parallel, one very thin layer of oak, and 1/8" of mahogany on the outside. The primary mirror is full thickness, and there is a big slug of brass behind the secondary acting as a stealth counterweight.
However, the optics hold their collimation no matter what. The only time I have to recollimate is when I remove the primary for some reason. The secondary just stays where it is. This is good because these scopes are a royal pain to collimate correctly. The secondary can't decenter by more that 0.020" or the image degrades. Everything needs to be stiff and stable.
Here are some more pictures:
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