Stepper motor help...STM5776

[john swift]

is the same motor used on the X axis ?

if it is, I would try swapping motors to see if the fault goes with the motor or stays with the stepper driver

what is the supply voltage powering the DM556 ?

using the rule of thumb from Geckodrives web site

ideal supply voltage = the square root of the motor inductance in mH x 32

with a 45V supply I would look for a motor with an inductance of 2.2mH
(you may find the nearest you can find is about 2.8mH )
and going by the label motor current = 4.2A

the NEMA motor sizes relate to the physical imperial dimensions
so a NEMA 17 will be 1.7" square and a NEMA 34 will be 3.4" square

John

[SweetAs]

Thanks John,

Ok so its a Nema 23. I never knew that about the sizes and Ive been using them for years....mind blown!

I have two power supplies in the machine, one with one live, which I am assuming powers the Nema 34 which raises the machine bed and one with 2 lives coming from it which I am assuming powers the 2 Nema 23s for the X and Y axis.

This is a.....

LRS-100-24
Input 100 - 240
Output 24v @ 4.5a

[SweetAs]

Pictures for reference.....

[john swift]

24V is lower than the 36V I expected

what is the other power supply rating

have you measured the supply voltage at the DM556 terminals
just in case the bootlace ferrule crimped joint has gone high resistance

John

[SweetAs]

I haven't checked the voltage but I can do that tomorrow just to make sure.

The other unit is a LRS-350-36 36v @ 9.7a

I'm on my mobile now so can't post a pic of it at the mo. Let me know if you need one. Thanks for the replies by the way John, it's very much appreciated

[paulus.v]

First check if the vibration is not mechanical.

Second and easiest to do, I would swap the X and Y motor plugs from the drives, the 6 wire connector, assuming two motors are identical and powered by the same psu. Now when you jog the X axis, the Y will be moving and vice versa. If the other axis is vibrating then the drive is faulty. NEVER unplug the motor and power plug from the drives before turning off the power!!
I cannot see if there is a plug at the motor end. If it has a plug, you could easily swap the motors as John said and this way you find if it's the stepper, cable or drive faulty.

Third but most likely, I would check/replace the motor cable, if your Y axis cable is the one that is moving inside a cable chain.

The stepper motor is the last thing I would suspect to fail.

[SweetAs]

Ok guys, I have just swapped the 6 cable plugs over and its the same issue. The x is running as smooth as and the Y jolts when it moves and stops so violently that the machine visibly shakes.

I'm going to check the connections at the motor end on the Y in a second, the machine will need to be disconnected and pulled out which is why I haven't done it just yet.

Any tips on checking the wiring at the stepper?

The Y wiring is static, the motor is fixed at the end of the axis and doesn't move so unless something has come loose I wouldn't have thought that the wire would have failed but who knows!