These rings are 6" O.D. for guidescopes up to 3-1/2" (90mm) diameter.

Each pair of rings are linked by a pair of stainless steel rods which act as stabilisers, the box-section structure thus formed is extremely rigid.

Generous amount of room within the outer rings for off-axis alignment.

All rings machined from solid aluminium alloy, split-rings (front) fix to the guidescope to avoid damaging it when tightening the adjuster screws.

The key to avoiding differential flexure - sturdy inner split-rings carry the guidescope, adjusting screw ends locate in grooves to prevent slippage.

Description:

The split-rings were added for several reasons, the first is that they enable the delicate tube of the guide telescope to be rigedly clamped without damaging it, and secondly, the split-ring itself has machined seatings for the adjusting screws. Very precise positioning is possible using this system, and the guider OTA will not shift or slip within the main rings. Using this system the guider can be removed from the accessory bar (complete with main rings) in the sure knowledge that it can quickly be replaced with accurate alignment maintained. The split-rings are also machined from solid alloy to the individual specifications of your own guide scope tube diameter. The bore is made 30 thousandth's of an inch over-size to accommodate a soft liner, the purpose of which is to prevent scoring the painted finish on the guider's tube.

NOTE: It is imperative that you specify the precise diameter of the guider's tube at the time of ordering - I will add the necessary clearance for the liner and machine the split-rings accordingly, therefore NO refunds will be made if you order a set and the rings don't fit! (there will be an additional charge for any extra machining to make them fit). I require the measurement accurate to nearest 0.005" inch (or 0.1 mm). Please measure in several positions and, if there is a little variation, quote the largest diameter.

The main rings have large diameter threads (3/8" x 26 tpi) for the alignment screws, they are precision screw-cut in a lathe (not die-cut). There is no 'slop' in these screws - they are also precisely concentric.

On each side between the pair of rings there is a 5/16" diameter stainless steel stabiliser bar which helps to hold the two outer rings in alignment with each other when removed from the dovetail bar. Also, when the whole assembly is locked together (the stabiliser bars, main rings, and dovetail bar) they form a box-section to provide maximum rigidity. Differential flexure due to weight shift in the rings is eliminated.

The bases of the main rings naturally have dovetail slots to fit the accessory bar (standard 1"), and a large diameter locking screw for each ring. The locking screw has a nylon face insert to prevent damage to the anodised surface of dovetail bar.

I hope the above description makes it clear why these rings are the best you will find, they are not cheap because all parts are precision machined and of high quality. Prices start at around £140 for a full set with 6" dia rings.

SEE PRICE LIST FOR ORDERING DETAILS

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