Hi Chip
When I wrote expansion I meant to indicate expansion or contraction but if you want to be precise, the expansion would be in the warm room when you set up the mount in the daytime.? Maybe I wasn't perfectly clear.? It's not the main issue just one of three.
The main issue in my experience is that the crown wheel is not perfectly round, which was confirmed by Scott when I called him earlier this week.? I was hoping to buy a mount that is mechanically perfect.? While a lot of the G11S mechanics are perfect AFAICT, the crown wheel is not.? Unevenness can be mitigated by adding some backlash.? The question is how to do this in a reproducible manner.? I use shims from folded aluminum foil.? If I keep having problems I will drive down to Burbank, it's an hour away.? It is not excessive but once the mount binds up after goto alignment you can start aligning over again so it's? a nuisance.
I find the directions about adjusting the worm on the YouTube channel not quite complete.? Without spring loaded worms the friction is highly sensitive to the radial pressure, so much so that it can easily bind up.? Shims or a feeler gauge are then necessary IMHO.?
That said, the amount of backlash needed for smooth motion is manageable.? So with proper counterbalancing in RA the main issue is resolved, good polar alignment mitigates DEC backlash issues.
