Re: Mount does not stop

Joe Zeglinski

So ... an intermittent problem - could it be a bad cable connection, in that
case? Give them a shake, and see if the problem returns. Perhaps the Y-cable
connector was just pushed on, rather than fully tightened down. Otherwise, it
will get you, just when you need the mount to work.


----- Original Message -----
From: "Dean Salman" <cluster@...>
To: <ap-gto@...>
Sent: Thursday, August 09, 2007 12:39 PM
Subject: [ap-gto] Re: Mount does not stop

Thanks for the tips. The mount was purchased new and was mounted in
an observatory not use all that often. I picked it up from the
observatory and in a nut shell, it s in new condition.

I will check the mesh, last night this issue never happened and the
pointing was perfect, I moved to about 10 objects and took an image,
it was almost perfectly in the center every time.

--- In ap-gto@..., chris1011@... wrote:

In a message dated 8/8/2007 7:37:31 PM Central Daylight Time,
cluster@... writes:

This is a used but only 4 years old. I will look at the worm mesh
which makes more sense. Again, as long as moving the mount with
TheSky does not cause issues, then I don't care.
Whether being moved by TheSky or by TheKeypad, the motors are
always only
controlled by the servo controller. The problem is not in TheSky or
TheKeypad -
they are simply software word generators - the problem must be
adressed in the
actual electrical portion of the mount. Please understand that
software cannot
move motors directly, it is the capture of the software words by
the servo
and then translating those words into electrical signals sent to
the motors that
results in the mechanical movement.

here are the possibilities:

1: not enough voltage for the motors to do the job being told by
the software
2: very tight worm mesh (can be caused by improper packing when the
mount was
sent via UPS or other carrier which can cause the motor box to jam
into the
3: faulty receiver/transmitter chip (UART chip) inside the servo
box - this
normally is a total failure, not intermittent and will cause total
failure to

If it is inside the servo box (CP2 or CP3), the mount can not be
from an external source such as the keypad or a computer, but the
motors will
still track at the sidereal rate. If the worm mesh is too tight,
then the
motors will not be able to keep up with the commanded motion, will
fall behind and
will try to catch up even after receiving a stop signal (stop
signal =
direction key not pressed).

If the mount has been purchased second hand, it is a good idea to
go over the
mount mechanically to make sure that all items work. It is quite
common for a
3rd party to pack the mount inadequately and ship it with little or
protection on the motor gearboxes. These motor boxes can be forced
into the worm by
blows received during shipping. You can check this easily when you
receive the
mount. Remove the motor gear covers and try turning the large spur
gear by
hand. If it moves freely, the motors can do their job. If it feels
tight, you
will need to reset the worm mesh - a job so simple that even I can
do it!!


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