Focus shift on lunt 60mm Crayford.

[Nigella Bryant]

Hi all, I've been experiencing focus shift and the focuser suddenly not moving whilst using the electronic focuser for the last few sessions. I tried tightening the grub screw at the bottom of the Crayford focuser but that didn't help. So the only alternative was to open it up and investigate the issue. I know the feather touch focuser is better than the Crayford but I have what I have. 

Upon investigation the only thing that struck me was a build up of black debris around all the wheels, shown in pic. Not unlike the days of the old computer mouse wheels (if you're as old as me you'll remember having to clean these every so often when the mouse wouldn't work because of fluf). Anyway I cleaned up all four of the wheels and put back together and it's working perfectly again. Nover taken a focuser apart before but it was a simple operation. Just a heads up if others begin to experience the same. 

The focuser is detached by undoing the three grub screws at the end of the red echtalon casing. You can see the build up of dirt on the last pic. The left wheel has been cleaned whilst the right wheel shows the buildup. 

Hope this may help other's. 

Edited June 12, 2020 by Nigella Bryant
Pic added.