Celestron CG-5 Question

[raymo]

Can any owner/operator of one of the above mounts help me?
The CG-5 has a function that enables one to change the direction the scope travels in when a given motor button is pressed. Having said that, last night,
when I tried a two star alignment, the scope moved first relatively close
to the star's R.A. and then proceeded to move about the right distance in
Dec, but away from the star, instead of toward it. My question is, if the
motor buttons are set to negative instead of positive, does that only apply when one presses a motor button, or does it apply also when the scope is
slewing itself? Second problem is that I checked the settings, and both buttons were set the same way, so if the Dec button was set incorrectly,
surely the R.A. button would have been too, resulting in the R.A. movement being in the wrong direction too, which as I said, it wasn't.
Confused:sc rewy:
raymo

[Camelopardalis (Dunk)]

raymo...I think you may be confusing two functions. There is one that controls whether or not left and right buttons are reversed (useful for SCTs) when they are pressed, but on my Nexstar that only applies at the slower slew rates.

The positive/negative thing is in the goto approach on my Nexstar. It controls the direction the scope is moved in final approach to an object. My understanding was that it is related to backlash, as when you're doing a star alignment the mount is calculating the offset, and you don't want it to be counting slews in the opposite direction to counteract backlash.

Sounds like the gotos were just off

[raymo]

Hi Dunk, I don't know whether you have a Nexstar alt/az scope or a CG-5
EQ mount, but on this mount both R.A. and Dec buttons can be reversed for
all speeds, which is a separate function from Go To approach, and the settings chosen must match the Go To approach settings, either Pos or Neg.
What I need to know is if one reverses the direction of the buttons, does this
then also reverse the direction the scope moves when receiving orders from
the hand controller during a star alignment routine, thus causing the scope
to move away from the star instead of towards it?
raymo

[Camelopardalis (Dunk)]

raymo I have the Nexstar alt/az, so I'm not surprised you can reverse the buttons in both directions, it would make more sense with an EQ mount.

Reversing the buttons just reverses the direction the scope moves when you hit that particular button. The goto approach alters the approach it makes to the star during star alignment. Neither should make it move away from the star though!

[raymo]

More problems. When slewing to the first star during a 2 star alignment, it
stops at its destination, and if you don't centre the star within 30secs or so,
it moves a further 45 or so degrees in Dec in the same direction, and after another 30 or so secs will do the same again, and again ad infinitum. Surely
the electronics must be stuffed. Also, I can adjust the R.A. motor speed at any time, but during a 2 star align[which is as far as I've got] the Dec motor runs at rate 9 regardless of my attempts to change the rate.
raymo

[Camelopardalis (Dunk)]

Hmmm...not seen that before you don't have a lot of luck with mounts raymo!

[Tony_ (Tony)]

Raymo,

I have a CGEM and a CG-5 (which I haven't used for a long time).
It sounds like it might be an electrical fault - but just in case its a software glitch it may be worth reloading the Hand Controller and Mount firmware.
If it works - good, if not - nothing lost.

Regards,
Tony.

[raymo]

Yes, good idea Tony. You're right Dunk, I don't; even the new Super Polaris I bought in the early 80s had huge backlash because it was so badly made that
I had to let it have a HUGE amount of backlash to stop it binding. The trouble was I got my wife to get it for me while she was in the U.K. and I couldn't afford the freight to send it back under warranty, so on that occasion I would have been better off buying one here.
raymo