开云体育

240 sec is the worm period of a G11 (and half the worm period of a GM8).? {Actually 239.344 sec}

The term "confounded" is used in statistics to mean when several variables can have the same effect on an outcome...so you can't tell what variable is making the effect.??

The 239 sec worm period is confounded with everything that returns to it's same position at that time:

1. The worm itself...can be bad.? Try exchanging the RA and DEC worms to see which gives the lowest PE...then keep the lower one on RA.

2. The Oldham coupler.? Ideally you want the Oldham coupler input and output shafts to be exactly in the same line.? Watch for the center white plastic part movement during worm driving...if that white plastic part is moving up and down or in and out, you should try to adjust your gearbox location (or inner drive shaft location if you have a tucked motor design)? (you may have to enlarge or slot the mounting ear holes if the older direct drive design) to minimize the movement of that center white part.

3. Transfer gears can wobble if you have a tucked motor system. Don't mesh these too tightly... have no tight point.

4. Inner transfer gear drive shaft can wobble if you have a tucked motor system.??

5. The gearbox drive shaft final gear also rotates at the same rate as the worm. Try a different gearbox.

As Alan has said, the worm period of all these mounts is very long (239 sec on a G11) and can autoguide out very nicely most of the time.? It is the faster oscillation from a bad gearbox (1/7.5 of the worm period or 32 sec on a G11), or a bad RA worm bearing ball getting pinched (~78-80 sec on a G11) that really challenge autoguiding efforts.

Have fun,

Michael