Re: [APML] Declination Drive problem

["William R. Mattil" <wrmattil@ix.netcom.com>]

Group,

First of all I would like to thank everyone for their comments. There
are a lot of issues here that I need to look at and I will take them
each in turn. First off, the Dec motor is a 120 VAC Hurst 1 rpm motor.
Since I had a few spares I set up a test scenario on my workbench and
what I found was that the Motor continued to "coast" for approx 10-15
degrees after power was removed. Digging around in the junk drawer I
discovered that one of them had a relay (of sorts) attached that
appeared to be a brake. This one didn't coast at all as long as the
relay recieved power. I suspect that this would be an imediate
improvement so I cobbled together a switching circuit to toggle this
relay when the appropriate button is pushed. Small diode bridge and a
solid state relay (input is 12 VDC which complicated things a bit) When
trying to attach the motor to the Tangent arm I found that the mounting
hole pattern was different. Strange since they *are* identical motors
:^). At any rate this seems to be an improvement. There still exists the
"slop" in the gears but this might be easier to control the overshoot I
was experiencing. 

Also mentioned was better drift alignment. This is probably a factor too
since I seem to have an easier time of this when I image from my
driveway. This is no doubt due to better polar alignment. My dark sky
location is 2.5 hours North and I do know that I need to raise the polar
axis just a bit as I run out of adjusting screw when drift aligning.

Now in regards to atmospherics causing problems..... I understand how
this can occur but what do you do when it does ? As I said I am usually
guiding at 303x. 9mm EP, 3X barlow and 90mm f/11. Does this seem to be
usable ? Primary instrument is 253mm f/6. The next time I try some
photography I will take the advice offered and see if it is a bit
easier. I may post an image if I get anything usable :^).

Again, thanks to all for their assistance in helping resolve what is
certainly a hopeless beginners problem.


Regards

Bill
-- 
William R. Mattil	| Fred Astaire wasn't so great.
wrmattil@ix.netcom.com	| Ginger had to do it all backwards
(972) 399-4106		| and... in high heels.

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