Most of the Dynamax RA problems I have resolved have been able to do so without Pressing the shaft out.
Mostly it has just been the grease has gotten hard and stiff, that causes the issue it is between the 2 RA drive/clutch plates that compose of the clutch, it can get so stiff you can hardly move the fork arms in RA.. The silver Allen screw on the opposite top side of the RA cap from the clutch flip lever is used for fine tuning the RA clutch after you clean all the old hard grease from between the 2 RA Drive gears/clutch plates. The slow motion knob is only engaged to the top RA gear/clutch plate. It has a small Teflon, or plastic tip so it doesn't dig a groove in the top clutch plate, when you fine tune the RA drift with the clutch lever partially engaged. They are both "toothed" The RA lock presses them into one another and the Bottom Gear is engaged to the drive motor. There is a locking collar that slides up and locks/adjusts the RA clutch plates.
I have used penetrating oil, and also used Gasoline and stiff brush. I once used #1 Diesel fuel.
Once you get that Mount freed up you will see why some people really love them.
Criterion intentionally drilled the Dec Slow Motion adjustment shaft holes "higher" so it bends it up from the slow motion arm. This makes turning it kind of stiff. I found it out on my first Dunamax, I thought the threaded rod was bad. When I took it out to replace it with
all-Thread I found the issue. You can open the holes up just a bit if you want to make it turn easier. It makes it hard on Dec motors if you put one on it.
I hope this helps clarify the issue and helps save you work. If this isn't the problem and the bearing is frozen, then you will be forced to press it out. Fortunately I haven't had to do it. IF the RA has slop in it when the Clutch is engaged (very annoying) you need to unplug ONE of the power leads from just ONE of the motors, let it run for a few seconds or until it takes up all the slop when locked.. This works for spur drive dual motor systems on Celestron C8's too. The reason for the dual A/C Motors is just that, to take up slop. It will run off one motor fine fut the gear reduction has play.. hence the dual motors so the drive gear is pushing a bit, and the other motor is dragging a bit so between the both it takes up all the slop!!!!I would certainly try every other option before I went to the extreme of pressing it out.
Larry "Duane" Beach
Edited by orion61, 25 August 2015 - 01:29 PM.