Roller bearings for Dobsonian mounts
Heavier Dobsonians with the traditional Teflon / ebony bearings often move too stiffly. In particular, when the instrument is swung in the direction of the zenith, the leverage is unfavourable and accurate tracking at high magnifications is not really possible.
GSO roller bearings are the low-friction alternative to Teflon/ebony bearings.
The modern version is an industrial roller bearing - as installed in GSO Dobsonians. The roller bearing gives a very smooth and uniform movement.
The advantages in a nutshell:
- industrial roller bearings, 31cm diameter
- includes two steel plates - for above and below the roller bearing, so that it does not embed itself into the rocker laminate
- central hole - suitable for 12mm bolts
How the rolling bearing works:
The rollers run evenly between the metal plates. The operational resistance can be adjusted by adjustment of the contact pressure via tightening the lock screw for the upper and lower rocker panels. The result is a uniform adjustment. The 'slip-then-stick effect' is no longer seen and, even at higher magnifications, there is no more resistance to be overcome between being completely stationary and beginning slowly tracking.
Installing the roller bearing:
This is very simple - no gluing and no screws. Simply remove the Teflon bearings and place the first metal plate on the lower rocker laminate, then comes the roller bearing itself, followed by the second metal plate on top of it. Then simply place the rocker on it and tighten the lock screw.