Arduino UNO + V3 CNC shield & A4988 drivers

I have a new project, a simple / small CNC platform, based on the following:

1- Hardware:
1.1- three NEMA17 stepper motors.
1.2- three A4988 Stepper drivers.
1.3- an Arduino UNO board Rev.3.
1.4- a CNC arduino shield V3
1.5- A 24V 10Amp Power supply.

2- Software:
2.1- GRBL 0.9j.
2.2- Universal G-Code Sender V2.

When I assemble the shield, Arduino, Drivers, Steppers & power supply, All seams good, nothing smoking...
The G-Code sender performs a perfect response, all parts are OK. BUT... oh BUT...
Axes X stepper is working perfect (as expected), Axes Z stepper is working perfect, and Axes Y Doesn't response at all...
I changed the Arduino... same default.
I changed the Shield... same default.
All steppers are working perfectly when installed at the X or Z ports...
All drivers are working perfectly when installed at the X or Z ports...
The PIN mapping is correct (physically at the shield, and by the GRBL mapping)...
My collage project is at held for that, and I am stuck... badly

Using the Multimeter,
Port X produces 1Amp when in RUN
Port Z produces 1Amp when in RUN
Port Y produces NO Amp when in RUN, but reads -0.81Amp if either X or Z in RUN

1 Like

Swap motors, swap drivers, post GRBL config.

Shahyn:
All steppers are working perfectly when installed at the X or Z ports...
All drivers are working perfectly when installed at the X or Z ports...
The PIN mapping is correct (physically at the shield, and by the GRBL mapping)...

zwieblum:
Swap motors, swap drivers, post GRBL config.

Most of us use GRBL 1.1.

Use a multimeter to check the cables for the errant axis.
And to check you are getting voltage to the driver.

We will presume you already set the operating current correctly ?
We will also presume you use heatsinks on the drivers and that the heatsinks are not shorting anything ?
We will also presume you checked the shield for any shorts or dry joints ?

And yes you grbl config may also prove useful.

GRBL 1.1 shows the same problem,
I am setting the current to 1Amp for all drivers,
The multimeter reads all connections as designed, for Y axes: pins 3&6 are OK, NO current output from the driver at this port (Y)
I didn't install heat sinks yet (still testing)
The shield has NO shorts or dry joints
GRBL config are good
Please re-read my post after my update...
DEEEEP in the Crystal ball, I changed every thing but my collage...

And we would still like to see the grbl config to ease our own minds about any settings.
Yep crystal ball fully occupied guessing what the wife will do next :smiley:

Driver has more than 2 pins. Are the all other pins connected to where they should be? e.g. is enable?