Focuser Operation - Meade ETX-70AT Repair Manual

Focuser Repair Note:
Let me begin by apologizing about
the poor picture quality. I was using a digital
camera on an old Sony Palm Pilot in a hotel
room at the time. J So on to the damage.
focuser would not function. In short, it punched a hole right out of the plastic back.

Focuser Operation:

The focuser on the ETX 60/70AT works by moving
the objective lens in and out on a threaded shaft. The focusing
rod has a step (the rod has a slightly smaller diameter at the
end allowing it to fit through the hole only about 1 inch) on
the end of the rod that stick out and the focusing knob is
attached. When you turn the focus knob the step presses on
the plastic inside the scope moving the objective lens away
from the knob. Focusing in causes the knob to be pulled to
towards the objective lens until it presses against the plastic
outside the scope then pulling the lens in. The slop in the
focuser is caused by the small gap between the knob, plastic,
and step on the rod.
If you don't want to, or are not comfortable completely disassembling your scope but need to repair a
focusing shaft pushed through the plastic, I recommend you use the 1/8 X 1 fender washer with one edge
trimmed to fit the scope. The larger surface area will provide a better bond for the epoxy. This method only
has a washer on the outside of the scope, while this will fix the problem, you do have a bit more slope in
the focuser compared to the complete fix. If you wish to install a second washer on the inside of the scope,
it will take a great deal of slop out of the focus and protect against another drop....
Ouch!!!
From what I can tell the scope must have
been dropped on the objective lens
shoving the focus shaft out of the OTA.
The "step" in the rod broke out the
plastic thus creating a situation where the