[ATM] Equatorial platform

["Geoff Nelson" <gjnelson@absamail.co.za>]

I have finished the electronics and tested the motor for my 
equatorial platform. Now i need to get on to the design of the actual 
platform.

The motor is a 48 step motor with a  controller that can do between 
10 and 240 steps per second. The motor has a gear box connected that 
gives a 250 times reduction. Originally from a UV Vis 
spectrophotometer.

If I am going to use a radial arm screw as recommended by Chuck Shaw 
on the atmsite. I will have a very low total gearing but also not be 
able to do a simple re-wind using the controller and reversing the 
motor and increasing the speed.

So I looked at the option of using the shaft of the gear-box as a 
roller drive. Chuck indicates in his article that as long as you are 
above 20 steps per second then the vibration should not be 
objectionable in the eyepieces. I am on that limit. This option will 
allow me to automate the re-winding of the platform easily

Now for the actual question. What have other people done to connect 
the roller to the 'cylindrical bearing'? Is it possible to use it as 
one of the support bearings rather than a separate drive entity? If 
you have done just this and have a website can you please send me a 
link so that I can have a good look at what you have done and copy it 
if it will work for me.

Regards
Geoff
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