Hello Guest it is June 19, 2019, 09:42:14 AM

Author Topic: burned a servo  (Read 13848 times)

0 Members and 1 Guest are viewing this topic.

Re: burned a servo
« Reply #30 on: September 17, 2012, 09:34:59 PM »
there's a limit pot that you turn on the Gecko drive. The Gecko isn't allowing me to turn up this pot switch enough to allow the servo to move the Z axis, the limit controls the voltage and or amps going to the servo. Even at rest if I turn the pot switch up past about 30% A fault light comes on the Gecko.

Not changing any settings in Mach at all.
Re: burned a servo
« Reply #31 on: September 17, 2012, 09:37:45 PM »
As far as I know... pins 6/7 control the Z... but they only send a 5v signal to the Gecko telling Gecko to apply power to servo.

If my servo won't even accept enough power at rest without faulting... it has nothing to do with the pins, computer, or Mach
Re: burned a servo
« Reply #32 on: September 17, 2012, 10:00:03 PM »
So your not moving yet and you are overdrawing current...so does that mean the holding torque is causing the fault? What does Gecko say instigates the fault light? Has to be a short or overdraw of current right? Check all your conductors to ground(a wire touching, bare?). Keep disconnecting conductors, power off course until fault goes away. If you lift 6 & 7 and the fault is the same then lift the wires going to the motor. Something you take away will stop the fault. Not sure if the lack of impedence will cause issues on the drive so be real careful about the conductors going to the motor. Don't want you to cause addtional damage.

RG

Offline Hood

*
  •  25,844 25,844
  • Carnoustie, Scotland
    • View Profile
Re: burned a servo
« Reply #33 on: September 18, 2012, 02:55:20 AM »
Have you tried swapping the motor and encoder wires to the X axis drive whilst keeping the X axis ports and pins settings the same?
Hood
Re: burned a servo
« Reply #34 on: September 18, 2012, 03:52:24 PM »
Found this for the G320 surfing about;

FAULT INDICATOR:

The FAULT indicator is on while the drive is in power-on reset, the DISABLE input is held “low” or if the protection circuit is tripped due to a fault condition. All power MOSFETs are turned off and all internal counters are reset. The FAULT condition lasts for 3 seconds, and then self-resets to try again. If the protection circuit tripped it and the cause is not cleared, then it will immediately re-enter the FAULT state again and repeat the cycle.

There are two conditions that will trip the protection circuit. One condition is if a short-circuit occurs and current exceeds 20 amps.

The other condition is if the POSITION ERROR exceeds +/- 128 counts causing a break of the servo-lock. This condition can have several causes:

1) The loop settings are severely under-damped and the motor breaks out into oscillation.
2) Excessive motor load due to acceleration or workload.
3) The speed command in excess of what the motor can deliver.
4) The current LIMIT is set too low.
5) The power supply current is insufficient for the demand.
6) The motor is wired backwards, is broken or disconnected.
7) Encoder failure.

Re: burned a servo
« Reply #35 on: September 18, 2012, 06:57:12 PM »
Thank you! On phone 3 times with gecko... never once did they mention this.

I'll trouble shoot with this later tonight.
Re: burned a servo
« Reply #36 on: September 18, 2012, 07:01:36 PM »
Thank you! On phone 3 times with gecko... never once did they mention this.

I'll trouble shoot with this later tonight.

Have you not read the G320 manual??  It's all in there....
Regards,
Ray L.
Re: burned a servo
« Reply #37 on: September 18, 2012, 07:25:23 PM »
i never got a manual, and i did look at gecko's site.... never found this info.
Re: burned a servo
« Reply #38 on: September 18, 2012, 07:31:30 PM »
Regards,
Ray L.
Re: burned a servo
« Reply #39 on: September 20, 2012, 01:18:15 AM »
I did buy another servo, just to make sure the one I originally bought wasn't faulty. put it on and same thing.

So now I'm 99% sure it's the encoder. Yes, I did try 2 new encoders... one of them I stole from a working axis to verify. Still same problem.

Earlier I did a continuity test of the encoder wires, going from Gecko to the encoder... checked out good... that may not tell whole story,. with just continuity.

I just did a resistance test of the encoder wires... they all read the same.

Everything now does point to the encoder... but everything checks out fine.

Am I missing anything to check dealing with the encoder? Does Mach have anything to do with the encoder that I could be missing with the problem I'm having?