Re: Can't adjust speed when aligning


GrayFox65@...
 

Paul,

Greetings from Fredericksburg. I noticed from a previous posting, on S.A.A I
think, that you live in nearby Williamsburg. What a marvelous historic
locale. My wife and I have visited there many times---we love the
architecture so well that we designed our house based on the Williamsburg
story-and-a-half style, complete with dormer windows on the upper floor.
Hope the seeing is good there---although truly good seeing seems to be a
rarity in Virginia, at least in the more settled areas.

You didn't mention which alignment method you are having trouble with:
Polaris, two-star or simulated star-drift. Unfortunately, because I live
among trees, I can't see to the North so I can't use the Polaris method, and
I can't see to the East so I can't use the two-star method. I'm stuck with
the simulated star drift method and can therefore only give advice on that
method. However, although it took me awhile, it does work extremely well
once mastered.

Nor did you mention eyepiece/magnification. I seem to recall that the
default N/S/E/W button speed is 64X, which, for me at least, isn't a problem
at low magnification. I always start the alignment process using a 55mm
Plossl, and ratchet up the magnification once I'm close. It takes several
seconds for a star to traverse the Plossl's 2.5 degree field at 64X. The
only eyepiece that gives me a little trouble is my 3mm Radian. At 365X,
stars do scoot by quickly. But even then, if one "taps" the N/S/E/W buttons
rather than holding them down, one can place the alignment star near the
center of the field fairly reliably.

Could it be that your controller is defective and is somehow erroneously
changing itself to a higher speed, say 300X, 600X or 1200X, rather than
staying set at 64X or at the slower settings you are entering?

Don't know what other problems you have encountered in getting precise
alignment. Fortunately, I don't have much orthogonality error. My 155 EDF,
rings, dovetail plate and Maxbright are all pretty well square. The biggest
barrier I've found is one that several of the first GTO mount owners
mentioned in the early going: loosening and then retightening the altitude
and azimuth bolts during alignment tends to move the alignment star out of
dead center in a high power eyepeice---just enough to be aggrevating. Early
on, someone suggested using two hex wrenches rather than one to tighten the
azimuth bolts simultaneously. This does indeed reduce the problem for me,
but it doesn't eliminate it completely. Also, tightening the altitude bolts
can cause some change of alignment.

However, with care one can approach perfection. As I've gotten better at
this, I've become rather insistent on putting things near the center of the
3mm Radian every time. Once one gets to that point---and it took me well
over six months to get there, during which time I made just about every
mistake that can be made---using the AP GTO mount (I have the 600E) is great
fun. My interest in observing has never been higher.

Best wishes,
Michael Masters

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