What happens when an EQ6 crashes

[focaldepth]

Not wanting to wish bad luck on anyone (if astronomers believe in luck) but what does happen?

Having gone through the first steps with a pier mounted NEQ6 taking every thing very carefully, I am now getting blasé and not even looking at the scope when doing gotos.

If the OTA (etc.) hits the pier do the motors just stall or do the gears start shedding teeth?

If the latter I was wondering about a simple trip wire (or ring) on the pier to cut power in the case of a runaway in addition to EQMOD limits.

Has anyone tried this?

[The Sailor]

Understand where you are comming from, had watched out for this when I moved over to the NEQ6 but so far all has been well. I did have this problem a couple of times with my CG-5GT and I was quick enough to pull the power, did wonderer if I should rig something like you said but never got round to it, maybe I am getting blasé .

Jim

[Zakalwe]

I would guess that the clutches would slip.

If you are pier mounted, then why not set up limits in EQMOD to prevent the scope hitting the pier? If EQMOD crashes, then the mount would stop tracking surely?

[blinky]

Mine has crashed a couple of times as I cant work out how to set pier limits - the motors crunch and stall but no damage yet.......

[chrisshillito]

If EQMOD/PC crashes then the mount will continue to track (if EQMOD isn't running whats' going to stop it?).

If the mount hits the pier then the motors will stall (steppers will slip) and make a terrible noise - no real harm will be done though other than waking up the neigbours.

Chris.

[Earl]

It does sound somewhat horrific when it happens :|

[focaldepth]

I would guess that the clutches would slip.

That is re-assuring.

the motors crunch and stall but no damage yet

That is re-assuring.

the motors will stall (steppers will slip) and make a terrible noise

Is that re-assuring? I guess you mean slip as in motor phase slip and not spindle friction slip.

So the consensus (so far) is don't loose any sleep over it.

I will keep my Hoopla hoop and a NVR circuit in reserve for a cloudy night though

[Beyond_Vision]

You could use a fuse that will blow at the motor stall current level. I have had my scope hit the pier a few times whilst doing an over night imaging run and falling asleep. No harm done to the mount as Chris stated. I too was thinking about a ring around the pier that would trip a kill switch. The only issue I can think of is cables brushing against it and killing power inadvertently.

Regards

Kevin

[focaldepth]

I am not sure that fuses and stall current really apply to stepper motors.

The hoopla loop could be on quite heavy springs/switches to guard against false trips.

[Skylook123]

When satellite tracking and a low flyer goes overhead, the rate is too fast for the system to keep up with the changes and the steppers do the same thing; sounds like a load of dining utensils dropped into a food processor. Scares the stray critters and the odd astronomer away.

[focaldepth]

I just re-read this, and I now have a picture in my head of the shuttle whizzing over head and a deafening NEEEEAAAAAWWWOOOOOOSH. Special sound effects.