I am thinking that a nice pipe mount would rival a DM6. By its very nature, the pipe mount is massive and heavy.
With well-lapped threads I would think it would make a high-end alt-az mount.
Show us pics of what you have !!
Posted 28 June 2017 - 08:12 PM
I am thinking that a nice pipe mount would rival a DM6. By its very nature, the pipe mount is massive and heavy.
With well-lapped threads I would think it would make a high-end alt-az mount.
Show us pics of what you have !!
Posted 28 June 2017 - 08:34 PM
would rival a DM6
nvr, that's blasphemy, god's gonna get you for that...
Posted 29 June 2017 - 05:24 AM
I made one years ago, with 1.5" pipe, and it was very sturdy and smooth.
I'm thinking maybe do it again with 2"+ pipe and spend extra time lapping it really well and use some teflon tape as well.
Posted 29 June 2017 - 07:43 AM
I used 2" on a pipe mount I made for my 102GT. It was an Alt-az on a Meade tripod I salvaged from a storage container find. It worked pretty well but was very heavy and has been replaced with a Twilight I.
In any case, I would recommend against extra lapping. I did that and it required electrical, not Teflon, tape to add the necessary stiction to make the mount usable.
Posted 29 June 2017 - 09:07 AM
Here is mine. It is my design and I call it a Delmarva pipe mount. I had article in Nov 2012 on how to make it. The noteworthy feature is that it requires no machining , but doesn't use the pipe threads but a simple to modify PVC reducer and some Teflon. The result is smooth 360 rotation with no play and easy to adjust friction.
You take the 1-1/4" to 3/4" PVC adapter and drill out the threads so the pipe slips thru. This is NOT the bearing surface so the hole doesn't need to be precise. The pipe just needs to slip thru the hole. I happened to use a 1" Forstner bit only because I had it. If need be you could use and file to file the threads out. Now you flip the reducer over and make two cuts at 90 degrees thru the threaded section down to close to the base. This makes four tabs that can move and squeeze down on the pipe as you screw it into the tee since pipe thread is tapered. You then cut a strip of Teflon and bend it into a ring. The strip is about 3/4" wide and a few inches long and made from 3/16" Teflon. This fits inside the reducer. This is the bearing surface and it wraps around the piece of 3/4" pipe that I used as the shafts. Now when you tighten the reducer, it squeezes down on the ring of Teflon which squeezes down on the pipe. The result is no play, very smooth motion, 360 degrees of rotation and you can easily adjust the amount of friction. You make four of these that screw in the ends of the two tees.
Here is picture of the my mount and the close up of the modified reducer.
- Dave
Posted 29 June 2017 - 12:49 PM
Hi,
Here is my pipe mount that I built recently and I'm using with my small refractor. It is build with 2.5" pipe and sits atop a surveyor tripod, which I also refurbished myself.
It is build with off-the-shelf parts except for the Vixen puck that holds the telescope and the flange that mates with the tripod. The counterweight is a commercial one, 1.8 kg with 20 mm bore. I lapped the threads using automotive valve grinding paste and I lubricated them with damping grease to take out the small play in the threads. I'm very happy with this mount, it is smooth and stable.
It is nowhere near grab&go but I don't like it grab&go, I like it stable.
Here it is pictured carrying a small 63/840 ATM refractor. The mount doesn't even notice this small telescope but I built it so big in anticipation for some larger refractors that I plan to build in the near future.
I'm now working on it to add setting circles.
Dorin
Posted 29 June 2017 - 04:38 PM
I love it. Great ideas guys.
Posted 29 June 2017 - 07:07 PM
Works quite nicely. just built it a couple weeks ago. My only complaint is the RA is a little heavy to move (like slow motion move) but it is quite rock solid. I need to make something to secure the legs of the tripod to a fixed opening. Now they splay all over the place casusing much cursing.
Posted 30 June 2017 - 06:18 AM
DaveG -
Nice. I like that idea. Do you have a link to your article?
What size pipe are you using?
Posted 30 June 2017 - 08:31 AM
DaveG -
Nice. I like that idea. Do you have a link to your article?
What size pipe are you using?
My article was published in Nov 2012 Sky and Tel. I used 1-1/4 fittings and 3/4" pipe for the shafts since it is close to 1" in diameter. The PVC reducer is 1 -1/4 to 3/4" . As I said you bore out the 3/4" threads in the PVC and the holes just needs to allow the pipe to slide thru since it is not the bearing surface. so it doesn't need to be precision hole. I use a 1" drill bit that I happen to have. Then you flip the reducer over and make two cuts at 90 degrees thru the 1 -1/4 male threads. You modify 4 reducers for each end of the two pipe tees. Line the PVC reducer with a strip of Teflon and when you screw the reducer into the pipe tee and it will evening clamp down around the 3/4" pipe I used as the shafts So you can easily adjust the amount of friction, there is no play, and you can continue to rotate the scope thru 360° and nothing loosens or tightens unlike pipe thread.
The scope won award at Stellafane in 2012 for this design and also a first in optics.
- Dave
Edited by DAVIDG, 30 June 2017 - 09:39 AM.
Posted 30 June 2017 - 09:07 AM
Brilliant
Are you a plumber?
Posted 30 June 2017 - 09:39 AM
Brilliant
Are you a plumber?
Nope, Research engineer/chemist with about 40 years experience in making telescopes and optics and 33 years designing and building scientific instruments. As my signature lines states "Engineering = taking what you have and making what you need"
Edited by DAVIDG, 30 June 2017 - 09:39 AM.
Posted 30 June 2017 - 09:44 AM
I didn't really think so, but I bet you could do a good job of it if you wanted...
Posted 30 June 2017 - 10:31 AM
Posted 30 June 2017 - 10:52 AM
So the load is taken up by the teflon strips, not directly
by any of the pipe threads.
Correct. The shaft slide through the PVC reducer and the Teflon inside the reducer is wrapped around the shaft. Because pipe thread is tapered as you screw in the reducer, the Teflon is squeezed down around the shaft. The Teflon ring is held in place by friction and the shaft turns inside the ring. The result is no play, easy to adjust friction and 360° of rotation with no change in friction. By making the two cuts in the males threads on the PVC reduces, you make four sections that can now move and squeeze down as you tighten the PVC reducer into the tee.
Here is a link to another thread were the author made my design. https://www.cloudyni...va pipe mount
He used lathe and 1-1/4 bit. You don't need a lathe. I just drilled out the 3/4" female threaded section with 1" bit since it is not the bearing surface, you just need to make the hole large enough so the shaft will slip through. You could use hand file to just file out the threads.
- Dave
Edited by DAVIDG, 30 June 2017 - 11:08 AM.
Posted 02 July 2017 - 02:12 AM
Another one, based on copper/brass plumbing parts:
Posted 02 July 2017 - 10:50 AM
Posted 02 July 2017 - 03:37 PM
Rob
Thank you for starting this thread , it is already a very interesting thread.
(No,no, not because I posted also here...but if you say so... )
My pipe mount was baptized ''Penelopa'' by my wife because it took me so long until I finished that Ulysse would get too old to worth something !
It is made with 1.5'' fittings ,the legs are from a surveyor tripod.
I'm working this Summer on a replacement , a RFT refractor of 60x260mm ...
Edited by ziridava, 02 July 2017 - 03:50 PM.
Posted 02 July 2017 - 05:57 PM
Dave G,
Do you have any "rules of thumb" regarding pipe diameter and tube weight, mount height, etc. ?
Back in the 70's Essential Optics sold Newtonian with Eq mount made from pipe fittings and machined couplings. Their 10" used 1-1/2" ones and I believe the 12" used 2" ones. So my PVC bearing design should work just as well or better then their machined pipe shafts and machined couplings. http://www.philharri...n.net/essen.gif
- Dave
Posted 03 July 2017 - 09:37 AM
Dave G,
Do you have any "rules of thumb" regarding pipe diameter and tube weight, mount height, etc. ?Back in the 70's Essential Optics sold Newtonian with Eq mount made from pipe fittings and machined couplings. Their 10" used 1-1/2" ones and I believe the 12" used 2" ones. So my PVC bearing design should work just as well or better then their machined pipe shafts and machined couplings. http://www.philharri...n.net/essen.gif
- Dave
Thanks for the info!
I might have to revisit pipe mounting. My original attempt used 2" for mounting a 102mm refractor, and so was quite heavy for what it was.
Edited by epee, 03 July 2017 - 09:40 AM.
Posted 03 July 2017 - 10:18 AM
Has anyone here ever made a pipe mount similar to the one in "Making Your Own Telescope" by Allyn J Thompson? It is machined with poured babbitt bearings.
![]() Cloudy Nights LLC Cloudy Nights Sponsor: Astronomics |