Homemade focuser accepts 1 1/4" & 2" eyepieces.
The focuser tube it round , It has a flat milled for the shaft to press against.
The thumb screw presses on a small piece of nylon or plastic which in turn
presses against the shaft. This allows adjustment for heavier eyepieces.
The milled flat also acts as a stop for the focuser tube.
The shaft runs straight through from knob to knob.
The knobs and shaft were salvaged from an old Meade DS 114 plastic focuser.
Looking straight down
There are 4 small ball bearings that the focuser tube rides up and down on.
I just went to a local bearing store and ask for the smallest roller bearings
he had. Approx $3 each.
The aluminum base was cut on a lathe to match a 12" od tube.
The focuser tube only makes contact with the bearings and the
1 1/4" to 2" adapter.