New build stepper help

**Leadhead** · 22-09-2015

New build, and new to building!
I have my three steppers working, But not smoothly. In fact they sound like they are driving on a cobbled street.
They components are pretty standard stuff, so hoping someone will be able to point me in the direction of a solution:-
Longs steppers 23HS 9442`s, Longs drivers DM542A (dippers 1 thro 4 off, 5 thro 8 on)
Standard Chinese 5 axis bob.
Mach3 P&P drives are Enabled. Dir.low active ticked and Step low active ticked.
Mach3 Motor tuning :- Steps 400 Vel. 3000 Acc. 600 - 0 step pulse & 0 dir pulse.

I hope it is something fundamental, but having lost two days experimenting. I really would appreciate some help if poss.

**Christian Knuell** · 22-09-2015

Hi,

what steps / rev have you set your driver to?

Steppers always make noise, especially when running slow and with a low steps / rev setting like 400.
If you set steps / rev to e.g. 1600 the noise should be reduced notably (but don't go too far - 3200 / 6400 will not improve much and your controller may not be able to keep up with generating steps for such high settings).

Another thing you can try is to put some rubber between the motors and the rest of the machine (if possible). This will dampen the vibrations and make sure the whole machine isn't acting as a soundbox.

Christian

**JAZZCNC** · 22-09-2015

Originally Posted by Leadhead

New build, and new to building!
I have my three steppers working, But not smoothly. In fact they sound like they are driving on a cobbled street.

Is this working on the bench or on the machine.? . . . . Motors need to be fixed on the machine or Clamped very securely other wise they will be affected by resonance and sound like can of marbles.

If on the machine then it could be several things. Resonance is the main suspect and Christien hit on the cure by changing the micro steps. Upping the steps will move the resonance to a different frequency which may suit your drives better. This is common issue with cheap drives because of there basic handling of resonance.

The next common thing is motor phases being wired wrong so check your wiring. Also make sure your signal wires don't run along High voltage wires like mains power or spindle wires etc.

Is it possible to video the motors running and the noise.

**Leadhead** · 22-09-2015

Jazz - - Thanks, the steppers are not fitted to the machine yet, and I am confident it is not a resonance problem as that was my trade. Hand held the steppers are clearly
missing steps. The axis is jumping every 1/2 to 1 every one revolution. It increases or decreases in proportion to the velocity setting.
Rod

**Leadhead** · 22-09-2015

Gerry of 2010 also suggested setting my step & direction to 15 which I tried to no avail.
I understand the direction must be longer than the step pulse?
Could it be motor phase problems?
Hair all over the floor!

**JAZZCNC** · 22-09-2015

Originally Posted by Leadhead

Jazz - - Thanks, the steppers are not fitted to the machine yet, and I am confident it is not a resonance problem as that was my trade. Hand held the steppers are clearly
missing steps. The axis is jumping every 1/2 to 1 every one revolution. It increases or decreases in proportion to the velocity setting.
Rod

Ok well one thing I've seen before on cheap drives is the pulse edge only works one way so to speak and if the polarity is wrong then they do weird shit.!! So try changing the active low and see if it affects anything.!

Other than that then it's down to either wrong phase wiring, bad PP cable or Poor low power PP port or BOB.!! Have you measured the voltage coming out the PP and the BOB.?

Presume you have tried on different drive and motor to eliminate a bad one.!