[gunsworth (Geoff)]

Another solution is to dispense with fixed counterweights and use adjustable counterweights.
Using a finder scope or big eyepieces on my 16” Lightbridge causes imbalance. Changing eyepieces from a 2” 26mm to a 13mm really upsets the balance.
My magnetic counterweight uses a lead acid battery for mass. The battery also provides power to the fan and dew heaters without messy cabling coming up from the baseboard.
Moving the counterweight up or down the lower part of the scope is a quick and easy way to achieve balance.
If anyone is interested, I can provide details on construction and pics. (But I do need help on how to post pics)