RE: ATM Alt Balance and Eyepieces

[Doug Tanaka <dtanaka@seanet.com>]

Gary,
<You didn't mention the size of your scope>
It's a 12.5" f/6

<Balance your scope for a medium-weight eyepiece.  If you're lucky, this means your scope 
won't nose dive with a heavy eyepiece, nor will it drift up with a lightweight one.>
I can easily change the balance with my bungee cord combinations, but it still drifts 
upward when heavy eyepieces are removed. 

<Move the Teflon pads on the side bearings further apart.  3.  Use Teflon Sheet (as 
described in the October '99 issue of Sky&Telescope) which has greater friction that 
ordinary Teflon, yet also has less stiction.  I found this cured the problem on my small 
Dob.  4.  Use a spring to increase the "virtual weight" of the scope.  This is what Orion 
does on their Dobs and it really does work.>
I thought about moving the Teflon pads further apart, but hesitate to do so partly 
because they are epoxied in place, but mainly because I love the smoothness of the 
movement as it is now (although I'm sure this is the reason it rifts so easily).  If I 
can get responses from others who have spread their pads apart with no loss of smoothness 
I would be tempted to give it a try.

Don,
< I would suggest using some sort of  mechanical toggle action so that the solenoid is 
only on for a very short time. The solenoid would only act as a trigger to change the 
mechanical state of the friction mechanism.  Alternatively, one could use two syringes 
tied together with tubing for a hydraulic method that uses no battery power. Or even a 
cable system similar to bicycle brakes. ( I just changed to V brakes on my MB)>
After getting your response and thinking about how I would make a mechanical toggle, it 
occurred to me that I should do away with the solenoid and use a small, reversible DC 
motor to operate a rack and pinion system.  I had thought about a cable system, but I 
would like to operate it while looking through the eyepiece, and didn't want to lead 
things lke this up to the secondary cage.  Cables, levers, etc. would add weight and also 
increase set up time.  I already have extra wires running through a truss tube, connected 
to a nine pin connector so set up and take down wouldn't change.

Thank you, both, for your responses,

Doug Tanaka 
Good luck!