jefferiksen I removed both set screws connecting the flexible coupling, but it will not slide off, it is still held tight.
What is happening is that the tolerance of the hole sizes on the flexible coupler is too tight relative to the EAF and focuser shafts. As you tighten a grub screw, it would dig into the shaft and causes a shaft to flare slightly and that is what is binding your coupler to the shaft.
I would first remove the L-plate completely -- but be caeful not to break the coupler. So that you have the EAF hanging by the coupler to the focuser. Again, be sure not to let it flop around too much to keep from breaking the coupler.
Not a big deal to break the coupler, since you can even find them at Amazon.
Remove the grub screws completely, just to be sure.
Now start at the focuser end -- since most focusers have higher quality shafts than the EAF shaft, and also you have something to hold on to (the main focuser knob). Try to apply a rotational twisting force first -- don't try to slide the coupler from the shaft yet. Just try to wiggle the coupler clockwise and counter-clockwise. Add a drop of WD-40 both at the shaft and into the grub screw holes. Once you can loosen (rotationally) the coupler against the shaft, then try to pull the shaft off --
I usually use a vice grip on one end and a ChannelLock on the coupler. Keep rotating back and forth as you try to separate the coupler from the shaft.
The EAF side is harder, since the EAF shaft appears to use some cheap soft steel that flares out more when the grub screws were tighrtened. And, unless you'd left some space in between the coupler and the EAF, it is hard to get even a needle nose vice grip in there. Again, the thing to try is to first loosen by trying to rotate the coupler back and forth first. That is why I always work to loosen the focuser end first, so that all you have in the end is just the EAF and the coupler that you need to separate.
Takahashi must use very stong steel shafts for their focusers since I haven't had a problem with that end. The Feather-Touch (FTF) shafts have also not given me problems. But the EAF end always give me problems -- the grub screws are much harder than the EAF shafts. ZWO really needs to choose their material with more care; like selecting grub screws that are less hard than the shaft, or use better material for the shaft -- it is just part of good engineering.
Chen
