Question Mount Worm Period

I am using stellarmate and ekos / indi and playing with the driving parameters, what they mean by ..... Mount Worm Period Info

Hi,
this describes small irregularities of the mechanics of a "regular" mount, which has rack-wheels / gear wheel. As the Avalon mounts do have belt drives there is no such worm period (but a periodic error).
astrojolo.com/gears/mount-periodic-error/
Because of the mechanics of gear wheel mounts each mount has its own periodic error which you can measure or look up:
github.com/OpenPHDGuiding/phd2/wiki/Mount-Worm-Period-Info
Guiding programs as PHD let you measure that periodic error. I never measured the periodic error of my M Zero but I´d be very interested in the result

.....Avalon mounts and the Periodic Error Concept
It must be stressed that the Avalon mounts requires an autoguider (but it can be easily guided by hand, thanks to its smooth, gradual errors and the quick response of the commands, event at the lower - 0.125X – rates). Furthermore, because of the technology used, having four different, very slow tracking curves, the PEC function is not useful (as well as the software generally used to optimize the PEC performances, which do not contemplate such a complex case).
While the tracking error generated by the transmission devices is large in absolute terms (typical, mean values are of +/- 5, +/- 7 arc-seconds), this is no reason of concern: the mount, which uses a four-stages reducer with tooth belts, has a very slow and smooth error, well spread over the time, so that it is very easy to handle with any autoguider, even while doing images with long focal length (2-3 meters) telescopes.
.....
....The mounts must be used with an autoguider and a slow correction rate, as 0.125X, but it is still possible to take unguided images with 500-600mm focal length telescopes....
source:
www.baader-planetarium.com/en/blog/avalo...fast-reverse-mounts/

..... With respect to the M Uno and periodic error, I have well documented the large PE on my M Uno. But to be clear, unless you plan to do unguided imaging it has absolute no effect on the resulting images or FWHMs. I think that Avalon should make it more clear on their websites that these belt driven mounts with multi stage reductions are unique, and while they do indeed have very large periodic error, it is so slow and smooth that it is inconsequential when guiding. I have taken single sub exposures of two hours duration at a focal length of 2350mm with guiding < 0.5" total RMS, with resulting round / tight stars with FWHM < 2"......
source:
stargazerslounge.com/topic/305846-avalon...astrophysics-mach-1/

hope this helps..
Peter