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.

[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