bigfish not with the EAF installed.
Remove the Lock thumb screw. You will not need it since the gear ratio of the EAF should make the EAF shaft stiff enough not to rotate by itself. The EAF becomes the locking mechanism when it is not moving. Even if you don't use that hole for attachment, you need to loosen the lock anyway, or else the EAF won't be able to move the focuser.
The center slot of the EAF mounting plate should pass right over the exposed thread.
Measure the diameter of the threaded part of the thumb screw with a pair of digital calipers. It should come up somewhere close to a metric round number, 2.5mm, 3mm, 3mm, 4mm, etc.
Find a metric screw with the same size but just long enough so that it will screw a few revolutions into the thread left by removing the thumb screw, but not long enough to do any locking (or else the EAF won't be able to move).
If the slot size is insufficiently wide for your screw to go through, just drill it out after measuring where it should be. You can also file it, but drilling is easiest.
The other screws along that center line on the focuser are probably tension adjustments, and should never be touched unless you know what you are doing.
Chen
