[Dman]

I just completed my setup of a HobbyCNC board and when I powered the system up I was getting a humming or almost air leak sound from the motors. Is this the chopper drive sound? I didn't have it hooked up to the computer yet as I need to get a gender changer for my printer cable. Is this sound normal or should I look this over again?

[Gary McCray]

Hi,
Motor noise from the HobbyCNC chopper driver board is normal. Mine makes varying amounts of noise depending on start up and stop positions of each motor, but not too loud. If it is really loud it might be a problem. If the motors work OK it is probably normal. Also, I am not sure it is a good idea to float the controller inputs by not having it hooked up to a computer which will initialize the outputs to the controller to a known state.

The Hobby CNC controller is a great little microstepping board at an incredible price and it uses one of the most advanced controller / driver chips available from Allegro. Although the motors run a little hot the board works great and it works very well with Mach2. HobbyCNCs 200 oz in steppers are very good bargains also.

[cncadmin]

All stepper motors make noise when at idle unless the driver board has a all windings off mode, which the hobbycnc board does not. Make sure tho that you have set the current for each motor.

[Sanghera]

I had the same problem, I moved up to a higher amperage power supply and same voltage, and it solved the problem. The way we figured it out was that when we disconnected one motor leaving two on, the motors didn't hum any more, it didn't matter which motor was disconnected. I hope this helps.

[janpo]

Have just finished my Sherline 5410 with HobbyCNC driver and motors and was getting a bit worried when i turned the thing on. I too get this sizzling air-leak noise, but it runs just fine.
With 3 200 oz-in motors, a 300 VA toroidal transformer and 30.000 uF caps it still makes this noise. I wonder how much more power it needs to stop ?

[ger21]

I wonder how much more power it needs to stop ?

There was a thread on one of the Yahoo groups about the HobbyCNC's noise. There's nothing wrong with it, that's just the way it works. I'm don't think a bigger supply will necessarily make it go away, as it did for Sanghera.

[HobbyCNC]

Its normal as noted in the last paragraph in the assembly instructions. A larger power supply is not a "cure". The humming will help prevent you from leaving it on accidentially.

Dave Rigotti
HobbyCNC.com

[Dman]

I have now used my HobbyCNC board to do alot of cutting and it works great. Very nice product and easy to build. I was very nervous about building and it was easy. The motor humming noise seems to be OK.

[Sanghera]

Ya, I'm not sure. I was able to try different power supplies and then buy one that worked best, so it worked out for me.

[rippersoft]

I just put a new machine in service with a power supply that I built which puts out 38VDC at 16amps. All 3 steppers hiss, but they move well in microstepping and the instructions said there would be noise. Don't worry, be cutting.

[rustyolddo]

As you increase the voltage, the quieter they get. If you build & use the 42V supply, they are almost quiet. You can't fully appreciate the HobbyCNC board until you run it at the max rated voltage.

[Mariss Freimanis]

Chopper-type step motor drives cause noise because of the design. It is normal and it cannot be eliminated. Other switching-type designs (synchronous PWM) create no noise at all but are more complex and expensive.

Mariss

[HobbyCNC]

Our PRO boards have MUCH less hiss than the older 4AUPC boards. Allegro has done their homework on this.

HobbyCNC.com