16 replies to this topic

[mrmusclesrocks]

Hello all,

 

This morning, I woke up to see my mount stuck at meridian. Apparently,  the way my scope was facing, my mount hit limits. 

 

It was probably like this for 6+ hours, will it be okay? Do I need to open up the worm gear and make sure everything is good?

 

This has never happened before, I was shocked when I saw. BTW I have a Losmandy G11G Level 6. 

 

Clear skies,

Michael

[emflocater]

 

Pier collision

A bit confused what your asking or stated by "Pier collision". Are you saying that the scope tube was stuck pointing at the meridian because it was wedged or butted up against the pier and thus could not move?

 

Cheers

Don

[mrmusclesrocks]

Yeah, the scope was stuck at meridian as the camera was pushing against my power supply. 

[Ionthesky]

This is probably a good question for the MOUNTS forum.  You might ask a mod to move it there.  I personally have no good answer for you, sorry.

[dnrmilspec]

Moved from The Beginners Forum for a better fit.

[pgandy]

Was it still running and pushing? I have two versions of the G11 w/Gemini II. On either one, if it encounters resistance, it will stop in RA or DEC (tight cable, obstruction, etc.) it will give a series of beeps, stop and display an alert. Ask me how I know. I believe the alert display is momentary. It remains powered up, it just shuts the motor down on that axis. This occurs under the factory settings, I've changed nothing. In any case I suggest you set up your limits accordingly for the worse case. Instructions are on the Gemini page.

 

https://gemini-2.com/

 

https://gemini-2.com/limits.html

 

Paul

Edited by pgandy, 11 September 2024 - 08:43 PM.

[Robert7980]

I’ve generally survived without damage when it happens… hard to say if everything is ok without some testing. If nothing looks obviously bent then it’s probably ok… 

 

It’s definitely not a good feeling walking out and seeing an expensive camera and filterwheel hard against something it shouldn’t be having a relationship with… 

 

Making sure meridian flip is actually enabled in the sequence is priceless. 

Edited by Robert7980, 11 September 2024 - 08:57 PM.

[idclimber]

I think it probably depends on the mount and how it handles these issues. I have only crashed my MX+ once and it simply shut down and started beeping like hell. I had forgot to set the limits and it hit the tripod leg. 

 

If the mount has enough torque and does not monitor overcurrent on the motors it is possible it might cause damage to the mount but I doubt it. I would not worry about it unless you start having tracking issues. 

I would spend some time setting up limits if you can in your mount software. 

[mrmusclesrocks]

Was it still running and pushing? I have two versions of the G11 w/Gemini II. On either one, if it encounters resistance, it will stop in RA or DEC (tight cable, obstruction, etc.) it will give a series of beeps, stop and display an alert. Ask me how I know. I believe the alert display is momentary. It remains powered up, it just shuts the motor down on that axis. This occurs under the factory settings, I've changed nothing. In any case I suggest you set up your limits accordingly for the worse case. Instructions are on the Gemini page.

 

https://gemini-2.com/

 

https://gemini-2.com/limits.html

 

Paul

I'm not sure. I also have a G11 GII at L6 so hopefully mine does the same thing. I didn't know if it was pushing. It managed to return to CWD position just fine after a couple beeps. 

[dx_ron]

I'm not sure. I also have a G11 GII at L6 so hopefully mine does the same thing. I didn't know if it was pushing. It managed to return to CWD position just fine after a couple beeps. 

Servo motors fail by burning out (I suppose it could either burn out the motor itself or the DC circuitry feeding it). If yours moves, then I'd bet it is OK.

[bbasiaga]

Your mount has the ability to set slew limits to prevent this from happening.  Read the online manual how.   There is also a Youtube video from Losmandy on the topic that is easy to follow.  It will stop the motors to prevent the collision from happeing, after the mount reaches an angle you set as a safety limit. 

 

Brian

[pgandy]

You should be okay. If I had a dime for every time I banged one of those mounts or slewed it into something I would have enough money to buy a more expensive mount and slew that one into something.

 

Paul

[dmilone]

The motors are connected to the worm gears by plastic or nylon couplers. I think they’re designed to snap out incase the scope hits the pier or gets snagged somehow and the motor doesn’t stop.
But I have an older g11. I’m not sure if the newer ones still have this feature.

[kathyastro]

Most mounts (I can't speak about yours in particular) use stepper motors.  A stepper motor doesn't have a lot of torque, and stalling it generally causes no harm at all.  The gears will be fine.

 

Check it out to make sure at slews properly in all directions.  Then set up mount limits in both hardware and software.  You want the software to detect the meridian passage first and handle the flip.  Set the mount to take action (either a flip or just stop) after the software has presumably handled it.  That way, the hardware limit will serve as a backup to the software.

 

I have my software set to flip at 5 minutes after meridian passage, and the hardware set to 20 minutes.  Before choosing these numbers, I checked that the mount will not have a strike before those times.  I expect the software to handle the meridian and the imaging session to continue from there.  But if it doesn't for any reason, the mount will stop tracking a few minutes later.

Edited by kathyastro, 13 September 2024 - 12:14 PM.

[mrmusclesrocks]

Your mount has the ability to set slew limits to prevent this from happening.  Read the online manual how.   There is also a Youtube video from Losmandy on the topic that is easy to follow.  It will stop the motors to prevent the collision from happeing, after the mount reaches an angle you set as a safety limit. 

 

Brian

Yeah I had limits set for my Old RC51 and never updated it for my SVX102.

 

 

You should be okay. If I had a dime for every time I banged one of those mounts or slewed it into something I would have enough money to buy a more expensive mount and slew that one into something.

 

Paul

Reassuring!

 

I'll test tonight and see how it goes. 

 

Thank you everyone for your replies!

 

Clear skies,

Michael

[Zambiadarkskies]

I can only speak for my AM5 and the current limits on that have saved my bacon a few times.

[bbasiaga]

The motors are connected to the worm gears by plastic or nylon couplers. I think they’re designed to snap out incase the scope hits the pier or gets snagged somehow and the motor doesn’t stop.
But I have an older g11. I’m not sure if the newer ones still have this feature.

The new ones with tucked motors have a gearbox with plastic gears that performs the same purpose as an engineered weak point.

Brian