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[ATM] scope rotation




    Sometimes the simplest answer can be the best.If you already have a 
saddle ring set-up holding the OTA,a few simple bearing blocks may be all 
you need.Three small wooden blocks carefully milled for the tube radii,will 
have a small 1"O.D.X1/4 I.D. bearing held with a 1/4"-20 case hardened 
socket hd bolt.
Off set the bolt so that it contacts the upper ring.The three of them set 
120 degrees will ride against the ring assy.If there is any unevenness in 
the rings,either file them out if the roughness is small or use your router 
to make a thrust bearing race from alum sheet stock.Make the thrust plate 
thick enough so it can be bedded on to the saddle ass.If you have a mount 
with straps like my Cave 8" Astrola,use the casting of the saddle as your 
thrust plate.Install enough bearings,(4 should do) so that any 2 are in 
contact with the plate.Adding a piece of 1/4" alum will extend the thrust 
area.My Cave has this feature.There are 2 knurled brass nuts that act as 
keepers to prevent the tube from slipping during a roll maneuver.It is 
simple,and it works.
regards,Ron

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