Problem: G11 Dec not turning.

[lazjen (Chris)]

I have obviously done something to the Dec motor system - probably bumped it too hard - such that it now does not turn the scope in Dec.

I took the motor off - it was quite loose. Using the hand controller, I could see the motor spinning fine for the various speeds. I then opened up the panel on the mount and saw the 2 gears there. Both seemed fine and turned freely. Hand holding the motor in position, I could see that it engaged the gears fine. Whether by hand or by motor, when the 2 gears moved, there was no movement in Dec.

I reattached everything securely but no luck. I repeated the steps being extra careful in case I had done something wrong and tried again. This time I got movement in one direction briefly, then no further movement in either direction after that.

Has anyone encountered this before? Any ideas for fixing? I'll go search the net for info, but I thought I'd ask here in case.

[lazjen (Chris)]

I'll try this in the morning. It was getting a bit hard to work, even with a floodlight near by.

Although my feeling is that it was working ok. However, I will test that explicitly.

[Hans Tucker (Hans)]

Can you swap motors on the G11? Try the RA motor on the DEC side? If you can then it may rule out the motor.

[lazjen (Chris)]

Another good idea, thanks. I'll add it to the list as I'm pretty sure I can do the switch.

[lazjen (Chris)]

Fixed!

The problem was mostly to do with the casing/cover that houses the gears. I did not have that properly on (it's difficult to see black on black in near darkness. ). Popping that on securely, reconnecting everything and I'm good to go.

[wasyoungonce (Brendan)]

Chris...did you dislodge one of the dimple rivets on the gearbox? This is a weak point and there is a mod to replace these rivets with small machine screws and nuts. Although Losmandy now has a newer gearbox which has metal rivets all the way thru the housings.

Brendan

[lazjen (Chris)]

I must have popped the whole box off as all 3 rivets had small bits hanging off them. However, after cleaning those off with bit more than a wipe/rub, the unit popped back into place fine and tight. I may do that mod in the future if required. Your newer gearbox link is a 404, but I guess it must be fairly recent change as this mount is almost 1 year old.

On the placement of the motors - how they stand out from the mount - is not the best design and is prone to being bumped or disturbed far too easily.

The plus side for this experience is that I now have some more understanding of this area when I need to do maintenance on the unit.

[wasyoungonce (Brendan)]

Hi Chris

link to the new gearboxes works ok for me but in any case here is a raw link:
http://www.gemini-2.com/Losmandy_New_Gearbox.php

I believe Losmandy is working on a motor mount mod to place the motors under the plate housing. I think other are doing this as well and there is the new Avalon stargo drive system that mounts the motors under.

I get the impression Losmandy is now fixing some issues and looking at longer term viability changes. They kept the same design since...well late 80's, which works well but could be refreshed.

[lazjen (Chris)]

Hmm, yeah, that link now works for weird. Anyway, I remember seeing both of those pages when I went hunting for solutions to my problem last night. "Cold" light of day made things easier to see and sort it out.

That drive system looks pretty good. If I ever have to replace the motors I'll have to look into getting those instead.

[wasyoungonce (Brendan)]

Sorry the stargo system is a stepper system so it needs the whole kit and kboodle to run it & well the handset is pretty plan no display...rather like an EQMOD system.

[lazjen (Chris)]

Ah, ok then, it's probably unlikely I'll need such a change. Mind you, I barely use the handset much these days anyway...