Do this with everything attached that will be attached during the session, including the camera, the filter wheel and the dew heater.
One: right ascension, tube horizontal
Loosen the clutch with the counterweight bar level and the tube horizontal. Slide the counterweight until the assembly stays put. If it will not balance with the weight at the end of the shaft, you need more mass rather than more shaft.
Two: declination, tube pointed across
Loosen the declination clutch and see whether the tube swings. Slide the tube forward or back in its dovetail until it stays. This is where a camera hanging off the back shows up.
Three: back to right ascension
Moving the tube in declination changes the right ascension balance slightly. A second pass is normal, and a third is not unusual with a heavy camera.
Four: rotate and check
Turn the mount through the positions you will actually use tonight. Some loads balance at one orientation and not at another, and that is worth finding now.
Five: route the cables and check again
Let every cable hang with slack, and turn the mount through its range watching for anything that tightens. Cable snag is a common cause of an otherwise inexplicable guiding spike.
The questions that keep arriving
Why do imagers deliberately unbalance slightly?
To keep the gear teeth loaded against one face so that backlash never shows during a correction. Whether a maker recommends it for a given mount is worth reading in the manual rather than assuming.
Does cable routing matter?
More than expected. A cable that tightens as the mount turns pulls on the tube and produces a movement that looks exactly like a tracking fault and is corrected in the wrong direction.
Last reviewed 17 September 2026