Bresser Hex Focuser Woes

[cloudsweeper]

AR102S - focuser jerky, and the knobs had gone a bit slack.  Here's how I fixed it.

The tension screws on the top and the lock screw underneath were kept at a very light finger-tightness.

Stripped the whole mechanism down.  Gently filed the flats on the shaft to ensure good grip.  Put new grub screws on the knobs so they could be tightened adequately on the shaft.  Put fresh grease on the pinion.  Reassembled it all.  Now for the delicate bit: the final adjustment.  There are four hex-drive screws under the assembly.  I slackened them all, then tightened the "lower" ones which hold the pinion against the rack, then turned them back half a turn.  Finally, I gently tightened the "higher" screws which push the pinion off the rack (and maintain its position).

And that's it!  A nice smooth action with no slipping or jerkiness.

The 'scope's in the astro-shed, so no photos at the moment, but if anyone else has had similar issues, I'd gladly take some explanatory shots.

Doug.