Counterweights, more weights mounted higher up the shaft or fewer mounted further down. Which is better? (AZ-EQ6)

[ONIKKINEN]

The question in the title, which is better?

More weights higher up the shaft would lead to a smaller "lever" effect as the mass is closer to the axis of rotation (perhaps damping vibrations), but it would also just increase the mass that needs to be rotated potentially leading to a stickier action which in my mount is already a bit too stiff. At the moment i have 2x 5.1kg that have to be mounted on the extension bar for the AZ-EQ6 and i at least know that this is not the right play. I have 2 old EQM-35 3.4kg counterweights being machined to fit the inch thick bar of the AZ-EQ6, leaving me with 17kg of counterweight potential. The 10'' scope i will mount on the AZ-EQ6 will be somewhere around 13kg with all the imaging gear on it. So should i put all the weights on the bar and have them sit quite far up and closer to the axis of rotation, or perhaps take one of the 3.4kg weights out and have them sit somewhere in the middle-lower portion of the bar?

My gut feeling is that its better to have more weight than less, but interested to hear what the SGL hive mind has to say on this.

[AstroKeith]

Given that moment of inertia is proportional to distance squared, if you are trying to make tracking adjustments, I would bring the weights in toward the axis.

[ONIKKINEN]

1 hour ago, AstroKeith said:

Given that moment of inertia is proportional to distance squared, if you are trying to make tracking adjustments, I would bring the weights in toward the axis.

All the weights then, adjustments when guiding is indeed the goal.

[Stephenstargazer]

In theory it should vibrate (wobble) less with heavier mounts closer in. But I think a lot would depend on the mount, tripod and other factors. The extension bar is defiinitely a negative factor.

[ONIKKINEN]

Guiding with the full 17kg counterweight package at the moment. RA guiding is solid, no major troubles.

DEC guiding not so good, but thats a story for another time and unrelated to counterweights.