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Whining noise from steppers

PostPosted: Fri Dec 22, 2017 10:02 am
by Gadget
I hooked up my machine to UCCNC for the first time today and notice a whining sound from the steppers.
I run 48V and Leadshine DM542 drivers.
At first it was terrible but after I did the self calibration on the drives it got much better, still very noticeable though.
I did not have this on my last Isel machine but that one was with their own controller.
Any ideas?

Regards

Re: Whining noise from steppers

PostPosted: Fri Dec 22, 2017 2:31 pm
by cncdrive
How noisy a motor is depends on the drive and motor and what it is driving and not the motion controller.
The motion controller only sending step and direction signals which is the position data for the drive and the drive is controlling the current and so the phases and angle of the motor.

Re: Whining noise from steppers

PostPosted: Fri Dec 22, 2017 7:44 pm
by Gadget
I understand that.
I just never had this problem before.
These drives are from stepperonline but perhaps they are not "real" Leadshine DM542,
My hopes were higher and I am not sure if it will be better if I buy 4 new ones, maybe DM556 for €80 a piece...
The motors are original Nanotech.

Re: Whining noise from steppers

PostPosted: Fri Dec 22, 2017 8:16 pm
by ger21
What microstepping are you using?

Re: Whining noise from steppers

PostPosted: Fri Dec 22, 2017 11:02 pm
by cncdrive
As said how noisy are the motors only depends on the drives, what current control algorithm it is using.
There are drives which using chopper type PWM current control which basicly sets a reference voltage proportinal to the phase current and the drive measuring the coil current and comparing to the reference voltage and using an on/off control to control the current in the coil. And moving the reference voltage according to the phase current it requires to set the actual angle of the rotor.
There are several sub types even in this chopper type PWM current control. Also the base PWM frequency may vary and some drives using a fixed PWM and some others using varying PWM frequency.
Also there can be different back emf current recirculating modes. Some drives have these also setable.
These so many things all influances how noisy or silent your motors will be and ofcourse the properties of the motor coils will also influance it and how the motor coil properties matching how the drive is controlling the current also plays in.

Some other drives using 2 PI controllers to control the current instead of simply chopping the current with a comparator. These drives are mostly more silent then chopper types, but they may require tuning of the current PI controllers or if that is not tunable then it can be unoptimal and can become noisy when the motor coil parameters are fully different from what the PI controller was tuned for in the factory.

There are again other drives which using voltage mode control when a sinosoidal voltage is shaped instead of a quasy sinusoidal current and the current is only limited in the stationary stage of the motor.
This is usually the most silent mode of controlling steppermotors, however it gives less torque and also it also limits how high voltage can be used to drive the motors. It is mostly used for smaller motors only, e.g. in 3D printers.

So, current control of stepper drives is a complex thing and how well it works depends on lots of factors.
I know these only because I have designed motor controllers for about 15 years. :)
Manufacturers ofcourse always trying to simplify it to a low enough level for the users to undestand and so they not have to do too many settings, but this often kicks back when they not allowing enough parameters to change. The easy solution for manufacturers is often to sell motors together with the maching drives.

I advice you to try to get drives which the manufacturer or seller of the motors advices to use with those motors. In other words get motors and drives which the manufacturer says that they are tested to work silently together.

And as Gerry wrote you can also try to higher the microstep count, because the more the microsteps the more sinusoidal the current will be shaped and so the more silent the motor will be, but the lower the torque will be on high speeds, so if it is good or not for your application depends on how oversized the motor is for the machine.

And you can also try to play a bit with the supply voltage, because if the drives using a fixed off-time chopper current control then the PWM frequency will vary also by the voltage you using and the inductance of your motors might push the PWM frequency into the audible range when using a higher supply voltage might help.