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[TCWORLD]

Hmm, still don't see anything untoward in the data.

In case you are curious, attached is a rough graph of the speed the mount is going based on differentiating the encoder values from the log files wrt to the timestamps in the log. The wigglyness is mostly due to the way I processed the data (the timestamps are not equally spaced so I had to interpolate and resample).

Actually this is the first time I've plotted the data like this, and it shows how my approximation of linear acc/dec is sort of working, but could do with some more work at the low speeds to get rid of the weird tails.

[cuivenion]

Yeah the graph looks fine, bit of a mystery then. Could it be something to do with eqmod by itself?

[TCWORLD]

The only thing I can think of is if it is caused by either backlash in the mount, or a loose pulley.

[Zh]

Its definitely backlash in gears as it happends to east direction. Star moves in Earth rotation speed while gears caches up.
Small effect is completely normal, but can be reduced or removed completely by gear adjustement and/or slight mount disbalancing.

[cuivenion]

Ahh, this rings a bell actually, I don't want to mesh the gears tighter so I'll live with it. Would the slight imbalance be towards the counterweight end?

Thanks to both of you for your help, sorry to have you running in circles there Tom.

[TCWORLD]

Could I get you to try the new beta firmware: https://www.astroeq.co.uk/forum/index.php/topic,107.0.html

See if that improves the behaviour with its new acceleration/deceleration routines.

[cuivenion]

Will do, soon as I get a clear night.

[cuivenion]

Hi, I've tried out the he new firmware and it seems to work fine. The east drift is the same, but here's the thing. I'm now using a different mount, and the east drift is still the same as far as I can tell. Maybe all these cheaper mounts have backlash like this.