To summarise, the problems with the Barska were:
- Too much slop in the worm gear; this caused an unacceptable level of backlash when operating the Right Ascension slow motion control knob.
- The counterweight is too light to balance my Celestron Vixen 80mm f11 refractor tube, which caused severe problems when trying to use the EQ-1 clone with my (decent) telescope.
- Needed to adapt the non-standard dovetail to my 80mm scope rings.
I loosened the tiny Allen screw at the three o'clock position in the above photo, adjusted the brass bushing with a long-nosed pliers, and tightened it up again.
To fix the lack of counterweight mass, I bought four 1.25-pound barbell weights ($1.00 each). Turns out three are enough:
I just wrapped some cardboard around the counterweight shaft because the holes in the middle of the barbell weights are much larger diameter than the shaft; I then tightened a hose clamp to hold the weights in place. Primitive! but effective.
A whole stack of washers and two ordinary 1/4"-20 bolts was sufficient to bolt the tube rings to the non-standard dovetail. I did hack at the dovetail holes with a screwdriver last night to make them large enough to thread a 1/4" bolt through.
I didn't extend the tripod legs, which left me almost lying on the ground (the moon was at the zenith). This made for much better stability but is not usable in the long run; I think I'll try my wooden tripod legs and see how much better that is. Wooden tripod legs are long and don't collapse though. They would be a pain to put in the back of the car.
Tracking was very good even with my very approximate polar alignment, and I can finally put that rolled sheet metal 60mm Barska toy refractor behind me (might make a good guide scope though). But now I want an EQ-1M motor, so that I don't have to turn the Right Ascension knob manually anymore.