Issue with Z axis driver (Error: short-to-ground on drivers 2)

fcwilt · 28 Aug 2018, 00:34

Hi,

Do you have any other stepper motors you could connect in lieu of the Z axis motors that are NOT part of the printer?

If not could you remove the existing Z axis stepper motors so they are completely isolated from ground?

The goal being to be certain they are or are not the related to the problem causing the short report.

Frederick

grahamcracker · 28 Aug 2018, 02:48

Frederick,

Thank you for the input. I have one extra stepper, so here is what I did to follow your suggestion:

I disconnected the 2 steppers set to Driver 2 and switched my config.g to the single stepper(ZA position, jumpers on ZB)
Connected the external stepper and connected the board back to main power supply.
Booted up the duet3d, homed X and Y just to make sure everything was still good. Then homed Z. Imediatly received the "Error: short-to-ground on drivers 2" fault but the stepper still rotated.
Lastly, I swapped out a different set of wire just to double check and received the same "short-to-ground" fault.

Regards,
Ryan

fcwilt · 28 Aug 2018, 03:28

Hi,

How is your Duet mounted?

Any chance there is a wire or something touching the underside and creating the short?

I have four sets of Duet WiFi/Duex5 combos in my printers and have never seen that error so I really haven't a clue where the short could be occurring on the board.

Frederick

grahamcracker · 28 Aug 2018, 03:42

The duet is currently on a rather nice cut of hickory, free from excess wire. There is also nothing resting on the duet and the wires are connected with the connectors that came with the board. There is a small gap for free air to pass under the board, so it doesn't over heat.

Regards,
Ryan

fcwilt · 28 Aug 2018, 05:10

@grahamcracker said in Issue with Z axis driver (Error: short-to-ground on drivers 2):

The duet is currently on a rather nice cut of hickory, free from excess wire. There is also nothing resting on the duet and the wires are connected with the connectors that came with the board. There is a small gap for free air to pass under the board, so it doesn't over heat.

Regards,
Ryan

Hmm...

Perhaps dc42 will jump in here with some info about possible causes of that message.

Did you try it with nothing connected to the Z-axes connectors?

Frederick

dc42 · 28 Aug 2018, 07:23

Please check the underside of your Duet to make sure that there are no solder bridges between adjacent pins of either of the Z motor connectors. We had an instance of this recently, which our testing didn't pick up because we test the Duets with 2 jumpers fitted in the Zb position.

Also try this: power down, disconnect both Z motors from the Duet, and power up again. Then try to home or otherwise move Z. Do you get the same message?

grahamcracker · 28 Aug 2018, 11:13

After checking the underside of the board there was no solder between any of the adjacent pins. The error message does not show up after disconnecting the motors.

So far the message shows when any motor of mine is in the following configurations: Za & Zb, Za and E1, and just Za.

Regards,
Ryan

fcwilt · 28 Aug 2018, 12:52

@grahamcracker said in Issue with Z axis driver (Error: short-to-ground on drivers 2):

After checking the underside of the board there was no solder between any of the adjacent pins. The error message does not show up after disconnecting the motors.

So far the message shows when any motor of mine is in the following configurations: Za & Zb, Za and E1, and just Za.

Regards,
Ryan

I assume you put the Duet connectors on the motor wires yourself?

Did you check the wiring to be sure you had the correct configuration?

Frederick

dc42 · 28 Aug 2018, 13:24

@grahamcracker said in Issue with Z axis driver (Error: short-to-ground on drivers 2):

After checking the underside of the board there was no solder between any of the adjacent pins. The error message does not show up after disconnecting the motors.

So far the message shows when any motor of mine is in the following configurations: Za & Zb, Za and E1, and just Za.

If the problem does not show up when the motors are disconnected but you try moving them as if they were, then it does suggest a problem in your wiring. Please use a multimeter to check the resistances as follows:

Between pins 1 & 2 of the 4-pin connector: 2.2 ohms
Between pins ~~2 & 3~~ 3 and 4 of the 4-pin connector: 2.2 ohms
Between all other pairs of pins on the 4-pin connector: infinite
Between every pin on the 4-pin connector and the body of the motor: infinite

EDIT: to be clear, by "4-pin connector" I mean the connector on the end of the motor cable that connects to the Duet, after unplugging it from the Duet; not the connector on the Duet itself.

Do your X and Y motors work correctly? If so, do they work when you plug them into Za or E1?

fcwilt · 28 Aug 2018, 13:46

@dc42 said in Issue with Z axis driver (Error: short-to-ground on drivers 2):

Between pins 1 & 2 of the 4-pin connector: 2.2 ohms
Between pins 2 & 3 of the 4-pin connector: 2.2 ohms

Hi,

That doesn't seem right to me.

Frederick

grahamcracker · 28 Aug 2018, 19:08

@dc42

Did you by chance mean:

Between pins 1 & 2 of the 4-pin connector: 2.2 ohms
Between pins ~~2 & 3~~ 3 & 4 of the 4-pin connector: 2.2 ohms?

Like this:

If so, this is how the motor's wiring has been configured and checked with a multimeter. When I get home from work I will confirm once more and rewire a new cable just to be certain.

Lastly, the x and y motors do work splendidly, I will test with Za and E1.

@fcwilt
I did put the connectors on myself. I purchased a crimp tool from amazon for the job:
IWISS Crimping tool, Amazon link

And for the wiring I used the duet3d wiring guide for the board and components.

Regards,
Ryan

kojderek · 28 Aug 2018, 19:54

Hello
I got similar problem with x axis, moreover my driver got fried. The problem was in motor wiring. One of the wires was crimped to much and got broken under insulation. The first thought was the motor problem because during X homing motor was shaking (short moves forward and backward) and "Error: short to ground driver 0" after second attempt to homing driver got fried. I checked wires and one of them was cut under insulation. Made new wire and remaped X motor to driver 5 and it runs with no problems. If one of the motor wires was cut why there was "Short to ground error"??? I am willing to replace fried TMC driver.

@dc42 can You provide me some advice in replacing fried driver.

As advice for anyone making own wires. Do not crimp terminal around insulation too strongly. The terminal blades may damage wire and always check wires with multi-meter. RUSH is Your greatest enemy.

dc42 · 29 Aug 2018, 08:04

@grahamcracker said in Issue with Z axis driver (Error: short-to-ground on drivers 2):

Did you by chance mean:
Between pins 1 & 2 of the 4-pin connector: 2.2 ohms
Between pins 2 & 3 3 & 4 of the 4-pin connector: 2.2 ohms?

Yes, I did - sorry for the mistake.