Dealing with backlash on a Refracter...

[Fozzie]

Hi all,

I've noticed recently that my 72mm ED scope with RnP focuser has a bit of slip in the mechanism (I assume this to be backlash.. please correct me if im wrong!).

Before I take to the Allen keys and start tweaking things around the focuser I thought it prudent to ask for advice on the process and mechanics of solving this.  The Scopes had previous owners, but I've only used it for visual with a 2" diagonal and at the heaviest end a WO Binoviewer..

Any hints or tips, is this something to expect again and again with use..?

Thanks in advanced

Fozzie

[xtreemchaos]

the rack on the bottom of the drawtube is in some focuser holded on by 2 screws or bolts, check thay are both tight cos that can cause slop, useally its the one at the lens end on the drawtube which gets loose.charl.

Edited July 13, 2016 by xtreemchaos

[Louis D]

Is yours similar to the Astro Tech 72ED?  I have that scope, and there is no backlash in my focuser because there's no rack and pinion, it's a modified Crayford focuser.  Slippage is always an issue at high altitudes and heavy loads, though.

[Fozzie]

Thanks Charl will look into those tonight and tighten any looseness..

 

Hi Louis,  it's probably not dissimilar to the AT72, but marketed by Altair astronomy here, and is offered with a RnP focuser.. quite a nice unit for stock one too..

 

Ta

Fozzie