[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


Steppers at idle


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

[lx007]

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

I'm having the same problem, also with a G540 and same steppers from CNCRouterparts.com. I'll email Ahren, he provides excellent support.

[jalien21]

Yeah, Ahren provided great daily support on this issue with me for several weeks, but we were ultimately unable to figure it out. We tried:

- Add a large filter cap to the PSU output
- Switched in a new G540
- Various grounding schemes / different outlets around the house / outlets at work
- Switch around all combinations of motors+G540 drivers

Nothing seemed to help with the buzzing sound. On the plus-side, I've been cutting without any problems for about a month, so I don't think this sound affects performance in any obvious way. The only thing I'm really worried about is that this might limit the lifespan of the motors somehow..

Let me know if you need me to test anything on my side.. I'd love to help debug this, but I know very little about stepper motors

[Crevice Reamer]

What size CL resistors are you using?

CR.

[jalien21]

The resistors are built right into the cables from CNCRouterParts. They're 3.4k (I've measured with an ohm-meter to verify).

On my set-up, the character of the noise changes as you turn the trim pots. I leave them fully counter-clockwise where they make the least noise. If I turn them more than halfway, the motor buzz starts to get very loud. Maybe this is a hint about the root cause of the problem? Does anyone know what these trim pots do?

Thanks!

[LGSM3]

Hi,

I have the g540 kit with 380oz motors from Ahren and it runs flawless, i guess i got lucky because it makes little to no noise.

I recently built a machine for a friend who ordered a deep groove 540 kit with cables and 280 oz motors. Without any adjustment it ran like hell, sluggish and untolerably loud at idle and while running. I was able to turn all of the trimpots counter clockwise as far as they would go and it made all the difference in the world. Still not as quiet as my setup but runs smooth and the only real noise it makes is a slight wine at idle.

The machine didnt seem to lose any performance that was noticeable by bottoming out the trim pots

[jalien21]

Hey LGSM3,

Do you happen know what the inductance is on your noisy 280 oz motors? Maybe this noise has to do with lower inductance motors like the 2.8mH 320 oz-in steppers from CNCRP.

[3space]

The same thing is happening with my test stepper (x-axis for now). I was about to start a thread on it. I currently have no resister (I thought that the G540 trim pots made it so that I didn't have to install one. Is that true?) on the DB9 connector.

[Crevice Reamer]

I currently have no resister (I thought that the G540 trim pots made it so that I didn't have to install one. Is that true?) on the DB9 connector.

NOT true. Even if your motors are 3.5A, you still need a resistor to enable the idle current limiting. Elsewise, your motors may run too hot.

What motors are you using?

CR.