Thanks Ian, that's good to know.? I think the inner block was misaligned because I had to make the flex couplers of my stepper fit, and those have some stiffness while the motor and worm were not perfectly aligned also.? Let me see if I can do a better job at that.??
Maybe an autoguider can handle it but I started looking into it because I get over 1" RMS and I expect this mount to do better.?
I added the spring loading because the mount had more backlash than I liked.? Tightening the worm would simply lead to the mount binding up, I could feel it manually.? The ring gear is just not round enough to have zero backlash.? Looking at the first graph (spring loaded configuration), it doesn't look much better than the second but at least it keeps the mount from binding up when slewing.
So I can pick my poison.? I can align the blocks as best as I can, tighten them, abandon the spring loading, allow backlash (hardly a problem for RA when tracking) and put up with the 240 second cycle and the backlash for slewing and plate solving.? Or I can keep the spring loading, improve it so the 75 second cycle is more regular than what we see in graph 1, and put up with the 75 second cycle.? Or I can drill out the holes in the blocks, apply Belleville washers and spring loading.? Let me try the non destructive options first.?
