Dual-Y Firmware Guide

If your machine is a dual-Y gantry, you can follow the firmware flashing tutorial to flash the dual-Y firmware.

https://www.bolangsk.cn/wp-content/uploads/asgarosforum/79/3axis_dualY_A-to-Y2.bin

Dual-Y Setup #

After flashing the dual-Y firmware, the original A-axis step/direction outputs become Y2, which moves in sync with Y, and the machine becomes a 3-axis (XYZ) machine.

Y2 follows the direction of Y (the Y bit of $3). If the two Y motors turn in opposite directions, swap one coil pair (A+ and A-) of the Y2 motor.

Automatic Gantry Squaring (Optional) #

You need two physical limit switches, one on each side of the gantry, both mounted at the same homing end. Connect both switches together to the Y limit input on the board: wire normally open (NO) switches in parallel, or normally closed (NC) switches in series.

Then send the following commands to set the homing order and enable squaring (homing must be enabled first with $22=1):

$Homing/Cycle0=Z
$Homing/Cycle1=X
$Homing/Cycle2=Y
$Homing/Squared=Y

Once set, $H homes in the order Z → X → Y. The Y axis homes in three stages:

1. Both motors move together to quickly find the switches, then back off once a switch is triggered;
2. Only the Y motor moves until it triggers the switch on its side;
3. Only the Y2 motor moves until it triggers the switch on its side.

Finally, each side stops at the $27 (pull-off distance) from its own switch, and the gantry is squared. Squaring accuracy depends on how the two switches are mounted; if there is any deviation, adjust the switch positions.

Notes:

• If only one limit switch is installed, do not enable $Homing/Squared. Otherwise, one motor will keep moving during homing and rack the gantry.
• Be ready to hit the emergency stop during the first homing. It is recommended to press each switch by hand during homing to confirm that both sides stop.