I have used the jumpers as directed - a jumper over each Z pin so that I can clone the Z axis onto the A driver.
When I test, the motor connected to the A driver works fine, but I then have issues with the Z driver.
I use the Universal GCode sender and send the sequence of commands:
G0 Z1 Direction = UP, all good
G0 Z2 Direction = UP, all good
G0 Z0 Direction = DOWN, all good
G0 Z1 Direction = DOWN, incorrect direction
You can see in the last step, that the direction is down instead of up.
With all connected, this causes my 1 Z axis motor to move the Z axis up while the other moves down - not a good experience for my machine.
Can anyone please suggest what the issue could be here?
Still no joy with this. I tried replacing the A4988 driver and updating from grbl version 0,9 to the latest version 1.1. Still the same response. This is really making me regret that I chose to design and build a machine with two z axis motors.
I am using a 12V ATX power supply to power the machine not sure if this low voltage could have some part of this problem.
To prove that its not my gcode that is the issue, I used Universal GCode sender, and jogging the z axis A driver, I get the same result. UP is not always UP and DOWN is not always DOWN. I also double checked the wiring again.
Well, now I have disconnected the end stops, and tried mirroring the second Y axis stepper onto the A driver.
I placed a multimeter pin on the jumper that controls the Direction of the A driver, and measured that voltage each time I changed direction from the PC, and the toggling of direction is fine, toggles hi and low without issues. So, the arduino is fine.
I did try replacing the driver with another, but I got the same problem.
I am going to try measuring the direction voltage directly on the Driver's direction pin. If this does not toggle, then the CNC shield is faulty.
I am also going to disable end stops in firmware as well to see if these steps resolve the issue.
If anyone has any other ideas or experience, that would great.
I measured the voltage on the A driver's direction pin, and it toggles correctly between 5V and ground each time I send a sequence of G0 Z1 and G0 Z0, G0 Z1 and G0 Z0 and so on.
So, there is nothing wrong with the arduino, grbl, the CNC shield, or the UGS software in setting the direction of travel.
The problem then appeared to be a driver problem. So, I swapped out the driver onto the Y axis and there was no problem with the driver on the Y axis slot.
So, I guess the next step that I have left is to disable the end stops in grbl.
Failing that, I will try connecting the driver as shown in
WOW a lot going on here but it seems so hard to do 1 thing.
I buggered up my board on my reprap pro very old printer.
I used a Arduino mega with a ramps 1.4 but it didn't like running
the 2 stepper motors of one driver so all I did was changed one line
to #define Z_DUAL_STEPPER_DRIVERS