Lyra is full of double doubles. Of course, there is the famous Epsilon Lyrae. That's the showpiece. But there are several other optical doubles just as nice to look at (though not gravitationally bound together). For instance, there is Struve 2470 and 2474. At 17x they are distant; at 60x they are nicely framed in my 100mm f/6. Then there is Eta Lyrae, and just next to it another double, also framed nicely at 60x. Beta Lyrae is also a double, widely split at 17x. In the same view as Beta Lyrae, one can also see Otto Struve 525, and this with Beta Lyrae creates a nice contrasting pair of pairs. I could dimly see the Ring Nebula M57 in the same view, on the square corner of a right triangle with the two double stars. Very nice!
Observations were made with 100mm achromat on the elevated DS-10 using S&T's Pocket Sky Atlas. I have discovered that the DS-10 goes back and forth between a bit too slow and a bit too fast. For part of the turn around the gear, its tracking is quite close to sidereal.
Here is the motor, worm, and drive gear of the DS-10. Adjusting it is very simple. Two allen bolts on the back of the housing plate (not visible in the images) loosen to allow the worm block, which is all one piece, to be moved closer to the gear, largely resolving the backlash problem. The motor is attached to the worm block, so there is no chance of losing torque or creating tension by adjusting the position of the worm. The three screws on the face of the round plate adjust the clutch. Tightening the clutch helped with the backlash, too, and the slight slipping I could feel as the clutch grabbed. Even I can adjust such a simple machine.
