Steppers buzzing with Gecko G540 while idle and high pitch when stop

[noobCNC]

I have a gecko g540 with new steppers. They are buzzing while idle quite audibly. Also, when jogging the axis and then stopping, sometimes there is a high pitch noise generated.

Im wondering if you can propose what may be wrong?

Bad driver? Bad motors?

[RomanLini]

That can be quite normal with chopper stepper drives (which the Gecko is one) and motors of a higher inductance. Because of the higher motor inductance the chopping frequency may be low enough to be in the audible range.

If you increase the PSU voltage it will increase the chopping frequency. Otherwise you could wire the motors in bipolar half coil instead of bipolar series, that will decrease the inductance but will also likely reduce the torque. Probably the easiest thing to do is just ignore the noise.

[noobCNC]

Ive wired them pipolar parallel already. Its quite loud and Im not even being picky. My old steppers you can hear some noise while idle if you put your ear to it. These ones I could hear from across the room. They are like this even when in stepper power test mode with the charge pump off to the G540, and not plugged into the computer.

Whats considered 'high' inductance? Mine are tiny steppers too, under 200Ozin and 2.4mH according to specs.

[Larken]

Check your power supply, Put a good 2200 uf Cap close to the drive.

What is the motor winding resistance ?

Gecko's are usually very quiet. Also the gecko isn't a chopper, its a PWM drive, which are much more silent.

[Tartan5]

Have you adjusted the trim pots?

[Ron Dunn]

The description "high pitch noise" means different things to different people

To me, it describes the stall noise of a stepper. I got this when I didn't use good acceleration values on a new machine. Since you've apparently changed your motors to something weaker than before, this might be worth investigating.

[noobCNC]

The high pitch 'whine' is a more accurate description. Its a short pulse. High pitch. Right at the end during the stopping/deceleraton. Analogy is squeaking sound of metal fork on metal plate.

Im trying to identify whether it is bad steppers, bad driver or both. My old steppers and driver are fairly quiet. I recently upgraded and got things setup but these are loud.

The resistance of the windings are very low (quickly measured from the DB9 termination using a 2 terminal instead of 4 point kelvin probe as thats what I have at home at the moment), and is less than an ohm around ~0.7ohms (including wire resistance).

[RomanLini]

It's normal for steppers to make much more noise at low RPM due to the increased per-microstep excitation energy (mechanical resonance).

So maybe you are hearing a noise during accel and decel, but it is much quieter when at top speed? That would be typical, and does sound like a "squeak".

If you run the stepper at a very slow speed (1 motor revolution every 2 seconds) does it make a much louder noise than at high speeds?

If you can run each axis at some different speeds and compare how loud the motor is compared to the "bad" noise it may give some clues.

[noobCNC]

I wasnt speaking about noise from the steppers while it was moving at low RPMs. I was speaking of the idle noise as well as the intermittent squeak at then end of movement.

Things are not wired incorrectly since they seem to move. Im worried about defective products with faster than normal failure. Keling quite apparently provides no after sales support for their products and stops responding to emails.

[Tartan5]

A picture is worth a thousand words. A video is worth 1000 words * (number of video frames)......

[Aussie Nerd]

Sorry to bring up an oldish thread, but I am experiencing the exact same problem.

Specifications are
Sieg X3 'Mini Mill'
CNC Fusion Deluxe ballscrew CNC conversion kit
425 oz/in Nema 23 X & Y Steppers
906 oz/in Nema 34 Z Stepper
Gecko G540
48v 7.5amp Ebay power supply
Controlled with Mach 3

On the power supply I have added a 50v 4700uF additional capacitor, as I found recommended in another thread about 'buzzing', however it has not appeared to make any difference. I also made sure the current limit resistor was at the db9 end, not motor end.

Note the Z axis does buzz, but a lot more tolerably then the X and Y, and it does not have a resistor. It is however a whole different motor. Also adjusting the trim of the motors simply changes the 'frequency' of the buzz, it's still just as loud.

All the steppers are wired in bipolar parallel, as specified by Keling/Automation tech in their datasheets

http://www.automationtechnologiesinc...H286-20-8B.pdf

http://www.automationtechnologiesinc...H295-43-8A.pdf

This is the control box I made for the mill.





Mill running
First test run of the Mill on Vimeo

Steppers at idle
http://www.vimeo.com/45429494

With the control box I have run the ground for the E stop and limits from Pin 12 on the gecko, not sure if that would cause interference? The motor wire is NOT shielded, is this likely to cause any great problem. Also the control box is plastic, again is this likely to be a problem?

Thanks in advance for any help
Kieren

[jalien21]

I am experiencing exactly the same problem with my G540 and 320 oz-in steppers from CNCRouterParts.com

Has anyone figured this problem out?

-James