DC servo hot plus strange ringing noise

Hi

I have a new motor running and its powered by the older 320 Gecko.
Both the old and the new motor produce a ringing noise and heat issues.
I did a test by removing the timing belt and running some g code for 20 minutes.
Even with the motor not under load the motor is getting warner. The z and x are
always cold to the touch. But the y axis is doing most of the work in my g code so
it’s working harder.
Here is a note regarding my setup. The power wires look to be a 18 gauge or even
smaller. I am ordering new larger wire and hope this will help.

PS. Here is a video of the machine running. Every 50 seconds I hear a ringing from the
servo motor. My ears tell me it’s the motor in question making the noise. I don`t know
enough about servos to tell if that ringing is normal.

The ringing occurs at 0.14 and .031 in the video.
The drive reduction on my machine is 3:1.
https://www.youtube.com/watch?v=4fFJ...ature=youtu.be


Regards Barry

Could be that your motor is verging on oscillating. Go through the Gecko tuning instructions and reduce the PID settings a bit.
If I'm correct, that will cut down the heating as well.

Cheers
Roger

Hi Roger
I never thought I`d get an answer. Thanks so much for taking the time to reply.

An off load motor should not make that noise and especially a DC brushed motor is usually very quiet.
Can you see exactly what the motor does when it makes that noise?
Could be excess gain, this is often audible when the motor is stationary.
Al.

It sounds like there may be debris in the motor, or a vibrating brush or bad bearing is making that noise.
Pull the brushes out and examine them.

bgolash

Sounds like a Bearing on it way out, the Bearing cage is skidding making the noise, you are hearing

Yeah, after listening a second time, I think I would go for the mechanical failure myself too. $$

Cheers

Hi
I have a new power supply that I wanted to test. I wired up the servo that had the noise. Ran the
servo and no strange noise at all. Does this tend to mean it could be a tuning issue. The test did NOT
include the motor connected to the 320 Gecko. Also both the new and the old motor are making the
same noise when I run G code. I assume again its a tuning or EMI interference problem.

It appears to be a DC brushed servo, so try it on a fixed DC supply if possible, an automotive battery is one such source.
If no such noise, then it points to tuning.
Al.

Quote:

---

Originally Posted by Novett

Hi
I have a new power supply that I wanted to test. I wired up the servo that had the noise. Ran the
servo and no strange noise at all. Does this tend to mean it could be a tuning issue. The test did NOT
include the motor connected to the 320 Gecko. Also both the new and the old motor are making the
same noise when I run G code. I assume again its a tuning or EMI interference problem.

---

Are you taking about the same motor as the OP, bgolash ? Or is this a different problem.

Quote:

---

I have a new power supply that I wanted to test. I wired up the servo that had the noise. Ran the
servo and no strange noise at all. Does this tend to mean it could be a tuning issue. The test did NOT
include the motor connected to the 320 Gecko. Also both the new and the old motor are making the
same noise when I run G code. I assume again its a tuning or EMI interference problem.

---

I'm sorry, but I could make very little sense out of what you have written.
I was under the impression that it was a motor which was making the noise, not the servo.
Are you saying that the test you ran with your new PS included just the PS and the Gecko, but no motor? Or what?
I'm confused.

Cheers
Roger

Its the same problem. Its a servo motor DC brush type.
To test the old motor it was attached to a new power supply.
The encoders were not used. Nor was it attached to a 320 Gecko.
I assume I should have mentioned I was bench testing the old motor.

Quote:

---

Originally Posted by RCaffin

I'm sorry, but I could make very little sense out of what you have written.
I was under the impression that it was a motor which was making the noise, not the servo.
Are you saying that the test you ran with your new PS included just the PS and the Gecko, but no motor? Or what?
I'm confused.

Cheers
Roger

---

Me too... Is Novett ,bgolash they guy who posted the video ? Huh ?

Hi Novett

I am still a bit confused. You keep leaving out half the essential details: without them no-one can help you.

> I have a new power supply that I wanted to test. I wired up the servo that had the noise.
Normally the word 'servo' would refer to a servo drive such as the Gecko 320X. Are you instead referring to a DC motor when you talk about a 'servo'?

If what you are saying is that running the motor straight off a DC PS does not make the same noise, then it is reasonable to assume that the Gecko 320X may be causing the noise in the motor. Yes, a DC brush motor can make quite a noise if driven by a supply with lots of oscillation on it. That then may be a servo (drive) tuning problem.

But not always. You haven't told us what sort of PS you are using. My spindle motor was very noisy when driven by an SCR-based servo drive; switch to a MOSFET-based servo drive and it was quiet. But I don't think that will be happening here.

Cheers
Roger


Cheers

Having viewed the video for the first time, their isn't enough info to go along to diagnose the problem.
First are you using a constant dc supply like a battery or are you feeding it commands through the Geckos? That makes a huge difference when trying to figure out if it's a mechanical problem.
If it was commanded motion then you have to look into tuning as it sounds like too much gain. The banging sounds, was that when it is reversing? Hard to tell.
DC servos are usually quiet. If it was SCR driven, you would hear that constant annoying hum, so for sure he's not using that.