Re: [ATM] Mirror Cells - Springs vs. Push/Pull

[Gilbert Gagne <ggagne@clearwire.net>]

Tom Krajci wrote:

>>From: Mark Holm <mdholm@telerama.com>
>>    
>>
>>Don Clement wrote:
>>    
>>
>>> <>Also there must be some sort of allowance for the angle change or 
>>> tip-tilt
>>
>>> <>of the bolt during collimation. That is what the flexure machined 
>>> into the
>>
>>>bolt if for. To allow for tip-tilt but be axially  and radially rigid.
>>>      
>>>
>>Maybe I missed it.  Did you post a drawing somewhere, or a description
>>in a previous message?
>>    
>>
>Ditto.  Please tell us where we can see a drawing/photo.  I have trouble
>visualizing the machined flexure.
>
>Thanks in advance.
>
>Tom Krajci
>Cloudcroft, New Mexico
>  
>
Perhaps I can help as I just made some push-pull collimation screws for my new telescope. My collimation screws are 3/8-24 stainless set screws which have been axially drilled and tapped for 10-32 thread, about 3/8" deep. I obtained from www.mscdirect.com some 3/8" diam SS balls which I also drilled and tapped for 10-32 thread. These I mounted on the end of the 3/8" set screws with short studs secured with thread locker. My mirror flotation bars are 3/8" thick aluminum which are drilled 3/8", not quite through. I then used a 3/8" carbide ball burr to form a spherical socket for the ball-end set screw. The ball-end set screw is held captive by a thin SS sheet metal plate with a 5/16" hole to clear the 10-32 stud. The ball burr is also from mscdirect. Total cost for three push-pull collimation screws is about $30. I can provide a picture to anyone interested.

Gil Gagne
Port Orange, FL
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