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Hello all,

My Astra IIIB was purchased new quite a few years ago and has had only moderate use, never been dropped, in good shape but has a very repeatable backlash of 2.0 minutes. The micrometer knob is tight on the shaft, the spring presses the gears together in what seems an appropriate manner, no loose screws,... i can get good sightings (within 1 nm with artificial horizon) if l always do the final turning of the micrometer in the same direction so the sextant is still very usable. However 2.0 minutes seems like a lot of backlash. Any ideas of what might cause this or simple actions that might reduce the backlash?

Thanks,

Doug Stephen