Is there a reliable way to check that my mounts axis is concentric? (HEQ5)

[pipnina]

Hello! I have been tuning my setup recently and got to thinking about why my mount would:

1: need to correct DEC error so frequentlyl if my polar alignment was as good as it should be

2: I get field rotation in my mosaics (at 2 deg by 1.5 deg image scale) when slewing in RA and after meridian flips.

I am beginning to think that one possible cause is that my polar scope is telling me one story, while the RA bearings are performing another. I am worried that my RA axis is actually gyrating as it turns and effectively moving the polar alignment as it tracks and slews. But I have no way to measure this for sure.

I have performed the belt mod and as such I have tuned the belt tensions and worm gear backlash, and to be honest while it's a big improvement the mount would lock up completely in some places but have backlash in others, which may also be a sign that things inside are not as true as they ought to be!

I think using Ekos/NINA's polar alignment system to get a good polar alignment on the east side, then resetting to home and running it again on the west side should give me a good clue? What do you guys think?

[Robindonne]

Could it be your polar scope need some calibration?

 

 

[Same old newbie alert]

Polar scope method is regarded as a rough alignment

[Same old newbie alert]

Have you looked at cone error rather than concentricity?