I wanted to pass along my experience with clutch disc? R&R on an old apparently never used Celestron G11 mount.? I believe never used because upon?inspection of the RA and Dec shafts?they did not appear to have any roller bearing track marks.? The original discs were completely saturated with grease [remnants of white grease].? They were stuck as if melted onto the mount's surface.? Once gently pried off and the surfaces cleaned, there remained faint very thin what appeared to be deposits left by the old discs.? Alcohol 99% then Brakleen failed to remove what at first I thought were smudges.? Close inspection of the old discs revealed what I would term delamination.? The marks on the alloy surface matched depressions in the old disc's surface.? I placed a call to Losmandy, they never encountered this and suggested using a razor blade to remove the residue. ? I took great care not to nick or scratch the surface in any way.? The material/residue was very thin and very slick making the (new) razor blade skip over its surface, the deposits would not budge, still visible and not easily felt with a fingernail.
Ok, bring out and test all types of solvents.? Finally some very strong Epoxy Paint remover, briefly applied then wiped off worked.? The spots/material was gone and I had not left any razor blade marks.? Whew.
While on the clutch disc R&R subject let me add:
Installing?the Upgraded Dec Clutch Disc, which was slightly larger even after trimming, the new disc?came into contact with three sharp protruding edged threaded holes on the Dec surface.?I then chamfered the?3x threaded holes?slightly removing those?protruding sharp edges.? Why I did not reduce the diameter of the disc to avoid those holes?? Well after careful, and time consuming trimming, using rhe Dec surface edge as a guide,?now having it?round and with out any edge/surface distorting cuts, the circle was just too pretty and why would you want less friction material anyway?
Another repair, which was not immediately noticed,? was the need to replace a bent Azimuth Adjusting SS Threaded Shaft.? Look for wobbling Adjuster Knobs while rotating the adjuster.? The !/4" -28 x ~3" rod could have easily been bend if the mount got bumped.
Also the Losmandy Azimuth SS shaft (AS)?as received had extremely sharp and rough threads which I thought might chew away at the brass dowel that rides on this threaded shaft.? Remedy; judicious use of Swiss files.
And after reassembly of the AS and adjustment, a dry run revealed that the original nylon washers had become pitted and the rotation was not silky - simple fix add 2 per side -?new 1/4" nylon washers.? Adjust for light contact.? Blue thread lock on one knob to shaft.? I could not source Mylar washers, maybe next time.? Why two - look closely at their surfaces one side is smooth and the other has manufacturing dimples.? I place the smooth sides in contact w/ the alloy surfaces.? Obsessive - yes.
