marvinrb1 I took the EAF off the focuser and it had no problems at all. I am really surprised.
Yeah, it is usually caused by the locking bolt of a Rack and Pinion focuser not being fully loosened. I usually remove them completely just so I won't mistakenly tighten them.
Some Crayford focusers' locking bolt cannot be fully removed (the tensioner and the lock are conflated into a single function), and you would need to loosend it "just enough."
Of course there is always the possibility that the ZWO EAF is too weak to "pull" the drawtube against gravity when the eyepiece end is fully loaded -- heavy camera, large OAG, large filter wheel, etc. In that case, you would need to get a higher end electronic focuser. Try it with the OTA horizontal with ground, and then positioned near zenith to test.
Chen
