I own a HEQ5 Pro with a belt mod and have a 50mm guider mounted on top of my 90mm refractor and use a QHY5L-II M.
I tuned the worm gear and made sure there wasn't any play or binding and it seems to work fine. I did also double check the tension on the belts which also seem fine with about 2mm of deflection.
I've been having significant issues with backlash in the DEC axis and especially within PHD2 which doesn't seem to handle it well at all so I've switched to the internal EKOS guider.
I've also set the guiding to only do DEC corrections in one direction as to minimise constantly changing directions, although this does cause issues when dithering and settling back down.
The internal guiding works well but I sometimes have sudden spikes, sometimes in both RA and DEC, other times just the one and I can't figure out why. Possible mechanical issue? The guide log I've attached does show them being in both axes but it does happen with the single one from time to time which causes me every time to bin the exposure.
I also experience a sawtooth graph in my DEC and was wondering how I could tune that out with the settings in EKOS?
For one thing, you stated that your guider focal length is 50mm, but the logs show it is specified at 170mm. That will drastically change the drift calculations.
The peaks may be caused by cable snags, presuming you aren't occasionally touching it.
Lastly, verify your polar alignment, as it appears to be drifting then making a big correction.
I have also belt modded my HEQ5, and backlash should be almost non-existent. So ensure again that the belts are properly tensioned and worms meshing is good. If you are still having issues, perhaps you have sticksion issues from old grease. Consider getting it serviced.
Okay, I've serviced the mount and regreased plus got new worm bearings, and unfortunately it hasn't fixed a thing. It still happens and quite regularly. I'm wondering of the possibility that it's a software issue?
I've enabled the logs for everything and have attached the file. If someone could have a look at it with the provided time stamps, that would be great.
20:55:50
20:54:00
20:53:13
20:51:18
20:41:42
20:38:20
I'm not sure if it shows in the logs but sometimes when it happens, I get these changes:
[WARNING] Warning: Invalid parameter -> Can not change rate while motor is running (direction differs).
[INFO] Align: current point is 1
[INFO] Align: current point is 0