Ad Astra Observatory

I spent the better part of the weekend trying to get an amperage reading off of the mount. According to a knowledgeable fellow G-11 owner, if the RA worm is properly adjusted, the mount will draw a very even level of power (he claims that his varies by maybe 1 or 2 mA, if that).

After learning some valuable lessons about “wired in serial” vs “wired in parallel” vs “wired inline”, I have a verdict. The mount draws about 0.4A as it’s idling the RA drive. However, I watch that number vary over about +/-0.1A (25%) as the worm idles. So I have some adjustment to do.

(Note: the meter must be wired in-line in order to work properly. + from power supply goes to + of meter. – of meter goes to + of mount. – of supply goes to – of mount).

Having said that, I’m not entirely sure what I need to do to adjust the worm. However, it’s nice that I can see a visual output from the mount. This means that I can do the adjustment during the day, which helps.

Among adjustments that I know of that I can make:
1) cleaning/regreasing the worm (done recently, but can be redone if necessary)

2) adjusting the worm (the mesh and position of the worm relative to the motor and the worm wheel and shimming if necessary)
3) lapping the worm (yikes)
4) replacing the worm with either a: a Losmandy brass worm ($60) or b: an Ovision worm/housing ($500)

So, for now, I’m sticking with #2. I’ll play around with the worm adjustment and see if I can make it work better. The suggestion is to play with it with the mount unloaded, get it set up correctly, then load up the mount and readjust the mount balance to make it work again.