Thanks for the input folks! What is the general feeling about University Optics' mirror cell for the 13.1" Coulter Mirror? Enough Support for a mirror that size (is it 1" thick? I don't remember). If the consensus is it's not sufficiently good support for a mirror that diameter, can you David (or someone with lots of ATM experience) suggest a design that a simpleton like me (or my neighbor) put together without too much trouble? Thanks again! /Rich --- On Wed, 2/29/12, Dunn, David <David.Dunn@supervalu.com> wrote:
From: Dunn, David <David.Dunn@supervalu.com> Subject: Re: [Utah-astronomy] Coulter question To: "Utah Astronomy" <utah-astronomy@mailman.xmission.com> Date: Wednesday, February 29, 2012, 9:58 AM The issue with the Coulter that I worked on is that it could not be collimated. The push pull system was stripped and wouldn't work. That is why I redesigned the mirror cell. Getting rid of all the weight at the back of the tube caused it to be out of balance. If you move the bearings, the tube will hit the bottom board supports so you either need to re-build the mount or add a lot of weight to the tube. His focuser was really sloppy so the focuser needed replacement. That would have required some tube to be removed from the bottom even if you kept the original mirror cell. I think we spend less than $50 on the whole thing since we only used a half sheet of plywood and used all the Teflon, etc from the original mount.
BTW, several of the telescopes that I have built use the same mirror cell so I did already know what I wanted there. In my experience, the secondary doesn't need to be moved much for collimation so once we got that centered it was ok and we didn't mess with it.
Thanks, David Dunn Software Engineer Sr.
SUPERVALU | Salt Lake Hardware Building 155 N. 400 W. 3rd Floor Salt Lake City, Utah 84103 Cell: 801.750.3198 | Home: 801.544.7705 | Office: 801.961.3253 david.dunn@supervalu.com
-----Original Message----- From: utah-astronomy-bounces@mailman.xmission.com [mailto:utah-astronomy-bounces@mailman.xmission.com] On Behalf Of Chuck Hards Sent: Tuesday, February 28, 2012 9:05 PM To: Utah Astronomy Subject: Re: [Utah-astronomy] Coulter question
Rich's original question was one of refurbishment, not overall re-design. Thus my question of available budget. Only the owner can answer that question.
An original Coulter Odyssey can be significantly improved without wholesale re-design. If we knew the budget available, concrete suggestions would be more valuable than simply "Throw the whole thing out except for the optics, and start over".
Based on Rich's original post, upgraded optical supports and a focuser upgrade seem like the first things to do- it's what he asked about, after all. Come on, people. Re-engineering the mount is secondary.
Starting-over from scratch is a distant third.
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