Leuwinga bob with Gecko 203V 4 axis

I would like to know if anyone knows a way of smoothing my stepper noise.

The noise is from the 4th axis (8 wire bipolar parallel wired)
A setting of 16000 steps/rev will give 36 deg/rev according to manual.

Current configuration
Linuxcnc 2.7
Leuwinga bob
5 Gecko 203v
A axis is rotary and noisy at most speeds but highest when slow.
4 wire steppers on X1, X2,Y,Z
8 Wire Stepper Bipolar Parallel on A axis.
Base is 15000 and runs great.

I hope someone has a solution.

Thanks,
Oz

Tom Thanks,

I've been digging and it might be the current setting.
I've got it on 3 amps and I think the motor is 4 amps but I am busy checking, I know it is at least 3 amps.

I will also recheck the wires.

Cheers.

OK so I can go up to 5 amps.

Wires are connected correctly.
Tuned the Geckodrive to eliminate the most noise.
Still not perfect but it will work.

The 4th axis unit is a worm drive and I have taken it apart and put back together ensuring all screw are tight.

I have it connected as follows for interest.
Red + Blue =A
Yellow + Black =/A
Brown + White = B
Orange and Green =/B

I'm not sure that there is a standardized color scheme for step motor wiring. Did you confirm it with motor manufacturers documentation, and or testing?

Confirm the continuity of each motor coil, and that none are shorted to ground or to another coil?. Test the motor wired half coil instead of parallel (disconnect one A and B pair) see if it runs smooth, then try the other set of pairs does it still run smooth and is the direction still the same?

Thanks Todd,

I checked the continuity and each coil was fine,
I checked the cables in pairs as suggested.
All turning in the correct direction but the noise was there all the time.
I tried something different, I disconnected the connections and put them on another Gecko drive.
Problem found, the stepper drive is faulty.
2 days and all that was wrong was the drive unit.

Thanks for the help.

Oz