[Dennis G]

In reply to a request for information regarding the bearings used on my Dob scope.
The 4 pictures attached may make this easier to understand.
Previous article, balancing the Dob, I mentioned using roller bearings. They were just that, simple plain rollers. These work well on the elevation, but suffered badly with sticksion on the azmath, so I replaced the 3 rollers with 3 sealed ball races. The angle supports are made from 1.6 mm aluminium angle and the shafts are stainless steel.
The base board and the curved elevation supports are routed to accomadate the bearing assemblies which should be accuratly made and with side clearances to run free.
Note. I used a centre ball race to take the 10mm pivot bolt which reduces further friction. The difference between Teflon pads and bearing rollers - my scope is a heavy brute - is just terrific!
If further info is needed please ask.
Dennis G.