M542 driver - motor vibration at low speeds

[birchy]

Ballscrews. The resonance is coming from the motor. I think I may have gone OTT with the drive cooling fans though? Here's me drawers...

. . . .

[John S]

Birchy,
Sorry can't help as never had the problem.
Don't run Linux in case that's the problem. having said that fitted rack loads of the 542's and similar motors.
Are these zapp motors ? Reason i ask is I had some [ not sure where they came from ] where the wiring colours wasn't what it seemed. Having said this bad wiring will be with you across the range, not just in a band.

So far all my conversions have been done with straight 4 core wiring to the steppers, never had an interferance problem to warrant screened cable, yes I know it makes sense but just never had a problem.

Done about five WM16's to date plus a few WM14's

[birchy]

I don't think your BOB is too close to the mains, I used CAT5 4core (2 x twisted pair) networking cable for the connections between the BOB and Stepper Drivers as this eliminates a lot of interference.
The problem you describe does not sound like a wiring problem and is likely to be resonance. I noticed the gap between the motor bracket and the machine was very small in places and I wondered if they were vibrating against each other like a tuning fork ?

I didn't think it was a wiring issue either, but wasn't sure if the steppers and drives are prone to doing weird things with mains cables in the vicinity, etc. Yes, the clearance are a bit tight in places but the motor is still resonating when I take it off the mounting and sit it on a rolled up rag. The noise is obviously less but the vibration can be clearly felt at certain low speeds.

[birchy]

Birchy,
Sorry can't help as never had the problem.
....
Are these zapp motors ?

Bugger my luck. Yes, they're Zapp motors. Bought them about 2 or 3 years ago and dragged my arse on the CNC conversion as I was doing manual milling. I'll take a look at the motor wire colours and report back...

[birchy]

More pictures and a video showing g1 codes at feed rates from 30 upto 2000...

. . .

[JAZZCNC]

How have you wired them Parallel or Series.?

If wires are Ok Can you swap with another motor.? If it's so bad it's rocking the machine then I very much doubt it's a resonance problem has often resonance happens at Mid band not low down and just makes motors run slow and sound terrible. It won't rock the machine. Same goes for having wrong micro stepping set, it will cause poor performance and horrible sounding motors but won't make the thing jump around.!

Doubt it's Phase or miss-wire issue either because like John says it would stay with you across the range.?

This may sound obvious but you have checked the machine mechanically first before blaming motors.?

[EddyCurrent]

Can't see your wiring for certain but looks like it should be

Blue/White - Red A+
Red/White - Blue A-
Green/White - Black B+
Black/White - Green B-

[birchy]

As I said before, the motor is vibrating when unmounted and has no load, so this is almost definitely a config issue. The machine doesn't actually rock about, however at certain speeds the vibration will catch it "in a sweet spot" and the whole thing sounds like I'm shaking a biscuit tin full of spanners. I'll have to re-check my wiring and try swapping to another drive, then another motor. Will also ask this question on the LinuxCNC forum as it may be a software setup issue...

And before you suggest using Mach, I'd like to point out that I've not used Windows since 2008. Yes, I'm a geek.

[EddyCurrent]

I worked on a Unix system early 80's and tried Linux a few times since but always went back to DOS then Windows however I recently got a Raspberry Pi so it's back to Linux again.

[JAZZCNC]

And before you suggest using Mach, I'd like to point out that I've not used Windows since 2008. Yes, I'm a geek.

Wouldn't have anyway has the control won't be doing this. This most defiantly won't be a software Config issue if thats what your meaning by Config issue.?
If you was getting missed steps or positional loss then yes.
Only Config setup thing it could possible be is Wrong micro stepping, after that it's something externally affecting motor/drive. Resonance is the most obvious and if your saying at certain speeds sounds like can of marbles then will be Mid band resonance in which case I'd say you have dodgy drive or motor has those drives are not known for having Mid band problems.
I don't think it will be noise either because again wouldn't do this and mostly would just have missed steps or some other strange happening.

Personally given the fact the motors have been stood 2yrs then I'd start there first and not the drive.