Steppers Noisy While at Rest

[TaK]

Hi,

I'm using a Gecko G540 and some Keling steppers and power supply. When my mill is not moving I can hear the steppers making noise. It sounds like static or a flickering sound. The steppers don't seem to be moving according to my dial indicator, and I don't think it's causing any real problem, but I don't like what I don't expect. Each motor seems to be making sounds, so it isn't just a bad motor.

I know the G540 is PWMing the coils when it's static to hold the motor at a partial step so if there was going to be any audible noise (which I wouldn't expect anyway since it switches around 20kHz) it would be more like a constant hum or tone since it shouldn't be changing.

I have tried grounding the power supply in a couple different ways and I have checked all my wiring.

Any ideas?

Thanks.

[PBr]

I was using Keling's motors too and there was that noise you described too. I think it is caused by PWM as you wrote, and it depends also on the motor type, construction etc.. If they don't generate too much heat while they're not moving, there is no problem.

[jasminder]

i was also having similar problem with a probotix stepper, the other one is very silent. But they are running without any problem. If your motors are 8 wire you can try connecting them in different configurations (i mean bi-polar parallel or in series etc) or try reducing the output Volts from your PS by 2 or 3 V.
i don't think they are bad at all.
jasminder singh

[Mariss Freimanis]

TaK,

Tell me about your power supply.

Mariss

[TaK]

The power supply I'm using is a Keling KL-600-48. 48V, 12A.

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It doesn't have a dedicated GND terminal, but I've tried grounding the case and letting it float; same behavior in both cases.

[Mariss Freimanis]

Tak,

Thanks, the reason I asked is because symptoms such as you describe can be caused by a power supply that has "issues". You have every right to expect the motors to be completely silent (as in no audible noise at all in a completely quiet room) while the motors are stopped or turning slowly. Let's go over some possible causes:

1) The drives may make noise if the power supply is a considerable distance (more than 2 feet or 2/3 of a meter) from the G540. Cure: shorten the wire length to 1 foot (1/3 meter) or if that's inconvenient, place a 2,000uF to 10,000uF capacitor across the power supply terminals of the G540.

2) Your power supply is a switching type. These typically have small output side filter capacitors and the supply may be bothered by the G540. Cure: try a 2,000uF to 10,000uF capacitor again.

3) If your switching supply has over voltage protection (OVP), this circuit may be spoofed the normal operation of the G540. Cure: try to disable this feature if you have the option on your supply or, try a 2,000uF to 10,000uF capacitor again.

4) Your power supply may be faulty. Cure: use a multimeter set to 'DC Volts' and measure the supply output voltage with the G540 attached. It should measure 48VDC +/-5%.

5) Your motors may be miss-wired for the selected current set value. An example is a motor wired in series with the G540 set to the motor's rated parallel wired current. Also double check your current set resistor value with an Ohmmeter. See that it is what you think it is; do this measurement with the DB-9 connector removed from the G540.

6) Your current set resistor is in the wrong place. I have reports of people using connector / cables with the resistor wired into the motor end of the cable. This will always cause the kind of problem you are reporting. Use the Geckodrive supplied DB-9 connector and always solder the resistor on the connector, never at the far end of the cable. Another reason to use the supplied connector is we include 5A per pin rated connectors, most inexpensive kinds are rated at only 1A per pin and they look the same.

7) It is a faulty G540; not likely but always possible. After you have tried and discarded all the other possibilities, that's what's left. Feel free to return the G540 for evaluation. It's free and we'll turn it around within one business day. Make sure to include a note describing the problem so our technicians know what to look for.

Mariss

[Drools]

Interesting, my 280oz@3amp steppers from Tormach do the same. I didn't think much of it last night as I was busy with the home switches and I had not done the trimpot adjustment as stated in the Gecko G540 manual. I will listen to the noise closer tonight after work.

[theoboeman]

Hi,

I also have the same problem of noisey steppers when they are not moving connected to g540.

I also have though the problem is my power supply.

I am looking to get a new power supply, which I hope will solve the noise problem.

What is the prefered type of power supply to use with the g540? regulated / unregulated - Switching or linear?

Would something like this be suitable?
Motion Control Products | Power Supplies | PS Range of Power Supplies

Many Thanks

Joel

[Mariss Freimanis]

Put a 10,000uF capacitor across the G540 power supply terminals. All noise will be gone.

The exception is if you are using 3rd party DB-9 cables with the G540 where the current set resistor is at the far end of the cable. We supply the G540s with mating DB-9 connectors. The current set resistor is supposed to be soldered on that connector. If it isn't, the G540 will be noisy and give sub-par performance.

Mariss

[dar303]

Hi,

Interesting thread! My motors on G540 with 36V chinese switcher psu also buzz, all I had was a 6000uF capaitor but that did not help at all so I just lived with it. Resistors are in 9pin dsub connector housings.
I'll dig up som heavier capacitors some day and give it a try.
The G540 works like a charm, excellent product!