Phil Lefever wrote:

Phil, it is a Synta scope. I think the black plastic piece is the bit
missing - I remember finding something like that but I've probably
mislaid it, not realising what it was for....

Thanks for the advice

Best wishes

Bruce
>
> Bruce,
>
> Which brand/model scope do you own?
>
> If its a Synta made model there are three shims that the drawtube
> slides on. The lower two that flank the focuser rack are white plastic
> and are glued in place. On the top opposing the rack is an adjustable
> black plastic glide. You will find two small setscrews that are on
> either side of the knurled lock knob. These adjust with a .5mm hex key
> to take up the free play.
>
> Does the above describe your scope? If you are missing a shim then
> they should be simple to replace and the Teflon would work well. The
> only trick is finding something that will stick to the Teflon! I have
> often added self stick Teflon tape to the stock glides to improve
> focuser motions.
>
> Let us know if your scope is different.
>
> Clear Skies,
>
> Phil Lefever
>