Guy's MkIII thrust bearing.

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Guy has fitted a thrust bearing to his MkIII. A very neat job it is too! 

Here is Guy's MkIII mounting after a tidy up and repaint. Note the screwed declination shaft. Suggesting a later model. As does the clarity of the Fullerscopes logo cast directly onto the polar axis castings and the pot base. Guy has fitted a longer pier pipe to raise the mounting for his refractor use. Originally this MlkIII held an 8" Fullerscopes reflector. The brass ring houses the ball, thrust bearing and protects it from the elements. The slow motion drives and motors, shown in an earlier post, have yet to be fitted in this image.

The polar axis is slightly withdrawn here to show the bearing assembly.

The thrust bearing with deep groove steel races and caged balls.

The brass bearing housing with the lower bearing slightly protruding to rest on the polar axis casting. Normally a MkIII would have a PTFE (Teflon) washer sandwiched between the castings to take thrust (end) loads. For lower friction with a heavier instrument the thrust bearing is a useful modification. The thrust bearing adds very little height to the polar axis so will not affect stability. The declination axis "T" rests on the upper brass face.  

The MkIII on its new, taller pier.



The "legs" are Fullerscopes Heavy Duty in cast iron. Offering greater stability  than the lighter, alloy model.

The MkIII stripped and ready for a repaint on its original, shorter, "reflector" pier.

The MkIII before restoration with its reflector.

 






An assortment of Fullerscopes parts and accessories. Including a threaded weight, finder/guide scope and VFO drive parts.






Click on any image for an enlargement.