PE Does Get Better With Use! (MEII)

PRejto (Peter) · #1 30-05-2016, 11:15 PM

I thought my tracking in RA was looking slightly less good recently so I decided to redo my PEC as it had been at least 2+ years since looking at it on my MEII.

I used PEMpro and was amazed to see my uncorrected error at +.9, -.9 arc-sec. (Last time I measured it was just over 3 peak to peak.) I was able to reduce this down to =.4,-.3 using 1 sec exposures at .88 arc-sec resolution tonight.

Gotta love this result.

Peter

gregbradley · #2 30-05-2016, 11:56 PM

Nice.

I have noticed in the past a mount I had for a long time improved over time.
Gears wear in.

Greg.

Atmos (Colin) · #3 31-05-2016, 07:25 AM

So by this reasoning, if I got one of the mounts build at the dawn of the 20th century, it should have a PE of 0.1"

Nice to see such low PE!

bojan · #4 31-05-2016, 08:43 AM

Yes, worm gear and worm are wearing and over time they are better adjusted to each other.

This process can be accelerated intentionally by menas of polishing with diamond paste. Of course, the assembly after washing and lubricating is critical.

Somnium (Aidan) · #5 31-05-2016, 08:57 AM

i am glad it worked for you

Shiraz (Ray) · #6 31-05-2016, 10:30 AM

Quote:

Originally Posted by bojan

Yes, worm gear and worm are wearing and over time they are better adjusted to each other.

This process can be accelerated intentionally by menas of polishing with diamond paste. Of course, the assembly after washing and lubricating is critical.

Peter's results are great.
Do you think it could be worthwhile to use a slightly abrasive lubricant for a month or two to speed up the bedding-in process on a new mount - then clean it out and go back to normal grease? guess there would be a need to keep any abrasives out of the bearings though.

bojan · #7 31-05-2016, 12:34 PM

Ray,
I am not sure about that.
However, a friend of mine did it with lapping paste, (1ml) using hand drill.
He let the worm to rotate 20-30 times in both directions (careful, you do not want this stuff in bearings), then dismantled and washed the whole thing, re-greased and put together exactly as it was before lapping.
I can't find his post (it was in yah0o group EQ6), but I remember he was tallking about achieving 2-3arcsec RMS.