Re: [APML] Setting up GP-DX mount

["Leo S." <l.stachowicz@btinternet.com>]

At 19:47 05/08/02 -0700, you wrote:
> For example, if the
> mount is rated at 22 lbs load, you can put 22 pounds of scope, camera,
> etc on it, plus whatever counterbalance weights are needed, making a
> total of well over 22 lbs.

Hi Bert,great,that gives me more headroom to play with!!


> but yes, if the
> GP-DX is like most drives, the two gears should mesh as fully as possible
> to get maximum surface contact between the teeth without causing binding.
> Depending on the diameter of the large gear and the size of the teeth,
> you may have only a couple of teeth on the two gears in contact or 6 or 8
> teeth in contact. I assume it is a worm gear arrangement? So you would
> want the shaft of the worm (the small, spiral cut, faster-moving gear) to
> be in the same plane as the large gear and precisely at right angles to
> the shaft of the large gear. Take all of this with a grain of salt ---
> not having one of these mounts, I don't want to lead you astray and it's
> possible that the designers of the GP-DX had some additional tricks up
> their sleeves that I don't know about. The one thing that is very much
> affected by the degree of contact between the worm and the large gear is
> the backlash. Lots of tight contact reduces backlash but also increases
> binding, so you have to compromise.

My wording was misleading for that question,i apologize,but the answer
you gave is still welcome and valuable information for me. I have found
the answer in the URL which Ray posted earlier here :

http://www.multimediamadness.net/wodaski/review_GP_DX.htm

where it says under : Evaluation of
guiding capabilities

"as it is up to you to establish a good and accurate
physical connection between the motors and the mount -- a single bolt
holds each motor in place. Use a straight-edge to get the gears lined up
exactly in a straight line"

...i think ill have to take that as meaning i should use a bit more
force to make sure the gear is pushed far enough along the gear shaft to
get both gears lined up. It seemed logical to me that they should both be
lined up in this way,but i just wanted to be sure before i went ahead and
destroyed a good piece of equipment. 

The instruction manual for the mount seems to be lacking in "small
details" which would otherwise make the mount much easier to setup
for the first time user,but i guess it is aimed more at an already fairly
experienced user!

> There is one
> statement in your note that sounds strange and maybe I misunderstood:
> 'sliding the wheel on to the
> RA "Decl. slow-motion control shaft" '    The
> declination axis and controls should be completely independent of the RA
> axis and controls. So you shouldn't be sliding any RA wheels onto any
> Decl shafts.

Sorry,my mistake again(long day/late night watching Perseids!) It should
have read :

when i was sliding the weal on to the "RA slow-motion control
shaft"

Thanks again for your help Bert,and everyone else. It looks like Polar
alignment is the next most critical priority for me(next to finding a
pair of small ball heads to mount in between cameras and the GP-DX
"accessory plate"(which looks like it could be very useful!))if
i am going to me ready in time for the Perseids to test the setup... I
know i'm cutting it a bit close!

Leo