Unbalancing (pre-loading) the mount prior to tracking? Is that a thing?

[Trippelforge]

Reading through my mounts manual I noticed it recommending to pretty much unbalance it prior to imaging. Which I guess is due to helping ease the motor strain and eliminate any residual backlash. I am curious if people ever do this? It notes that you should only do it slightly, which honestly seems pretty subjective. But after shooting for years with my old mount I had never done it before, as I always assumed the mount needed to be dead perfect the entire time.

Is this a wise thing to do? If so how much is too much?

[vlaiv]

Depends on the mount and the way you guide.

Amount of "preload" or imbalance will depend on how aggressive is your guiding in terms of guide rate.

In any case - it should be slight - enough for gravity to keep the gears engaged when changing guide direction.

Not needed on mounts with minimal backlash or pure belt reduction system of friction drive or direct drive. All those like as close balance to perfect as possible.

[ollypenrice]

Yes, if you have a little backlash in RA, then running slightly east-heavy will leave the driven gear resting against the drive side of the driving gear rather than oscillating across the backlash. It does mean that you need to reverse the imbalance after a meridian flip.

There is an equivalent procedure to reduce Dec backlash but which doesn't involve balance weights. You can deliberately polar mis-align the mount slightly then activate only the guide direction which corrects for that. You don't run the guider on the other direction. Trial and error decides which inputs to disable and, again, they need to be reversed after the flip.

While I've had reasonable success with both methods, this was only as a stop-gap measure prior to fixing the problem properly.

Olly

Edited November 3, 2023 by ollypenrice
Clarification