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G11 Gemini stopped tracking

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#1 charles genovese

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Posted 22 April 2013 - 09:39 PM

odd problem- last night the alarm went off. Have had this happen when at a mount limit (or scope runs into somethin like observing chair) but wasn't either and although scope wasn't tracking it slewed normally in both directions. Mount is always balanced. Tonight I pulled both motors and no RA binding ( I knew it wasn't)- When I get through the startup menu and the RA motor runs fine, but as soon as I touch a button on the hand control in RA (+ or -) the motor stops.Exchanged motors and cables with the same result. Still slews fine. Went through the time (battery obviously still working) and mount parameters- all "nominal". Any ideas? Thanks

#2 Hilmi

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Posted 22 April 2013 - 11:34 PM

Gearbox is jammed. Check the gearbox cover is not separated. If you keep on running it you will burn out your motors

#3 tidroplane

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Posted 23 April 2013 - 02:48 AM

Sounds like a power issue, I had the same thing happen when I was running my mount off 12v. I now use a Pyramid power converter, converting from 12v. to 13.5v. and have never had the issue again, Losmandy mounts like a higher voltage, You can find a Pyramid converter Amazon for under $25.00 hope this is of some help.

#4 charles genovese

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Posted 23 April 2013 - 05:58 AM

Don't think gearbox is jammed- it's doing it with the motors removed. Also, using the 120- 12V power supply so not that either.

#5 Hilmi

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Posted 23 April 2013 - 01:36 PM

Unless you have either disconnected the gearbox too or loosened the clutches, a jammed gearbox will still interfere with movement. Only reason I am pushing for this explanation is that if I am right and you don't check it out, you could burn your motors.

#6 charles genovese

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Posted 23 April 2013 - 03:58 PM

As I said it is doing this with the motors unattached to the mount

#7 wasyoungonce

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Posted 23 April 2013 - 04:42 PM

Charles

Here's what I'd try:

1. 1st, cold boot the system and check the limits are not at the wrong settings, aka something hasn't changed your Gemini limits or settings and your system thinks it's at one of the end limits. This stops RA drive! But also usually gives a buzzer.

2. Connect your Gemini via Gemini ASCOM (via RS232) then switch the Gemini on, cold boot and run it via the Gemini ASCOM, use the virtual handset to command drive and slew the system not the actual handset. (you do not need to have the motors in the mount to do this,

Also use Gemini ASCOM to look at the Gemini Advanced settings to see if something isn't set right!

Anyway if it works with Gemini ASCOM then well I'm not sure .... :confused: but I reckon it sounds like a hardware issue with RA drive.

But before we jump to conclusions do get back on cold-reboot and Gemini ASCOM tests.

Brendan

edit:
I just re-read.....You said the alarm did go off...hmmm sounds like the Gemini lost it's positional way and thought it was at it's limits...cold boot (Counterweight down) and check the Limits, use Gemini ASACOM to do this.

#8 tidroplane

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Posted 23 April 2013 - 08:39 PM

With your 120-12v.system, exactly how many volts are actually getting to your mount?

#9 charles genovese

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Posted 23 April 2013 - 09:36 PM

It's the Radio Shack power supply that used to be on the Losmandy site. 12V. It has always worked perfectly. Doubt that's the problem. As for mount limits, doubt that's the problem- restarted the mount numerous times, with motors reversed and wires reversed. It clearly has nothing to do with the motors, wires or mount limits. Has to be in the controller. Will not have time to download all the ASCOM stuff tonight. I do have the Sky 6 and have run the mount with that. Will try again tomorrow.
I keep thinking this has to do with the battery in the controller going bad. It is about 2+years old.

#10 wasyoungonce

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Posted 23 April 2013 - 09:47 PM

Gemini ASCOM has a full range of Gemini settings reported to you and you can change them...this program is the cat's pyjamas for anything Gemini.

Batteries at best last 2 years (with the CR2345) the CR2032...much less.

A battery issue could corrupt SRAM data, this has no effect when system booted and running on internal power, although a bad battery may have corrupted the data already.

#11 charles genovese

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Posted 24 April 2013 - 06:00 AM

Stupid-stupid- got it fixed! It hit me while I was sleeping!
Last couple of times I brought it out I was causually observing and just used "warm start." And kept using that to restart the mount. All I had to do was properly follow directions and "cold start." Course it was the mount limits all along. Time to order a new battery also.
Thanks everyone.






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