tube rings too big

[starstalker]

any ideas on how i can make 90mm diameter tube rings fit an 80 mm diameter ota?

[Psychobilly]

Rubberised cork sheet will allow you to build up the gap...

http://shop.ebay.co.uk/?_from=R40&_trksid=p3907.m570.l1313&_nkw=cork+sheet&_sacat=See-All-Categories

Peter...

[jgs001]

Is the outer diameter of the tube actually 80mm ? Both my 80mm refractors use 90mm tube rings as the outer diameter of the tube is 10mm larger than the diameter of the lens cell. I can't find the outer diameter of the tube for the DS2080 online anywhere, but the pics don't look like the tube is narrower than the lens cell..

How much gap is there between the rings and the OTA ?

[starstalker]

id say it was about 5 mm, i did think that the 90mm would fit thats why i ordered them but they dont, couldnt find 80mm anywhere

[Merlin66]

I have the same issue with a non-standard OTA diameter on the Genesis.

Like Pete suggests; I used some cork gasket material to make three wide pads and make up the gap. Works 100%

Ken

[saturn5]

any ideas on how i can make 90mm diameter tube rings fit an 80 mm diameter ota?

I turned nylon tips on a lathe ,drilled and tapped them to match the existing threads,just screw them on.My 100mm rings now hold a 80mm scope.

[starstalker]

great thanks everybody for the tips,looks like the cork is the easiest path to go.