what's the PE on the old AP 600E and 800 mounts?
Posted 30 November 2012 - 12:35 AM
Well I'll buff the bushings as Ed says, use the anti stiction grease, and see...
Posted 30 November 2012 - 09:44 AM
The actual ingredient of the "limited slip" additive is jojoba oil.
Posted 30 November 2012 - 10:30 AM
I took apart a Vixen GP and it also had bushings.
I would not consider this to be "bad design" - Ed Thomas can probably weigh in here but well-made bushings would probably outperform poorly-made bearings (like those in the China mounts).
This is also why you've got a lot of folks replacing the bearings in their China mounts with Timken or SKF bearings.
I had thought about replacing the main declination bushing with a large bearing - but it would require massive machining and destroy the value of the AP600 as an antique / collectible.
There used to be a long waiting list on AP600's - I can imagine Wally toiling at the mill / lathe making each of these by hand without benefit of CNC
There is certainly nothing wrong with a well designed and implemented bushing system. The precision needs to be high though and wear could certainly be an issue faster than a bearing system. It might be possible for a good machinist to make a new set of bushings to replace the old ones. But I would want him/her to be a very good machinist to do it right.
Posted 30 November 2012 - 04:26 PM
Do you think that a bushing design would put the same amount of strain on the same portion of the bushing and overtime result in uneven wear? This should be inherent to the design, correct? Unless the mount is always perfectly lubricated.
Posted 17 March 2013 - 04:19 PM
Posted 17 March 2013 - 10:51 PM
The raw PE is about 8" and it gets down to 2" with a good PEM training (which took me a long time, because the 9000 controller is "dumb" and a really good polar alignment is required to avoid RA drift).
In summary... with a very good polar align, declination guiding is minimized and the DEC stiction issue can be side stepped.