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Old 08-10-2009, 08:48 PM
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kinetic (Steve)
ATMer and Saganist

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Join Date: Jun 2008
Location: Adelaide S.A.
Posts: 2,292
Bert would it rotate at a linear rate or non linear due to
the ellipse at its heart?

Being a servo motor with optical feedback I suppose that
could be speed adjusted to make it a linear rate.

My homemade GEM has almost zero backlash now with
the worms meshed properly....press the track on/off
button and it simply starts tracking.

PE is another thing altogether...I have a slight PE curve
due primarily to the non-concentric worm.
PEC zeroes most of this out.
That doesn't mean I can take minutes long exposures
at 1500mm FL.
That will simply never be possible for me.
No amount of autoguiding or PE will prevent the stars
from ending up as blobs over minutes.

Bert, Fred,
Wouldn't belts contribute a similar trait to spur gears?
The only method with almost nil backlash would be a roller
drive method.

Interesting little devices that's for sure.
Steve
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