[gnea/grbl-Mega Issue#179] CNC Machine not moving and just making weird jerks

Hey everyone – I’m kind of new to using GRBL, so apologies in advance if I make some silly mistakes here. I’ll try to add as much information as possible to this post, but please let me know if you need any additional information. Thanks in advance!

My machine is currently running grbl-Mega-1.1f, and I’m using the pinout from https://github.com/grbl/grbl/issues/390#issuecomment-140977241 to wire up my stepper drivers. This pinout seems to match up with the cpu-map.h file I have.

I tested each of the steppers individually (just some simple Arduino code to run a stepper) and they seem to work just fine. However, whenever I upload GRBL and try to use UGS, nothing seems to move. Instead, every time I try to send a jog command, the machine just jerks around slightly but doesn’t actually move. Regardless of what axis I command to jog, the X-axis always seems to have a slight jerk to it. I’m really not sure why this is happening so any advice would be great!

My only thought is I didn’t actually wire up the stepper enable/disable to any of the drivers from the Arduino. I figured that’s usually optional, but could that be causing issues somehow? Not sure why that would only cause issues when I use GRBL though.

Regardless, I’ve attached my settings below. Feel free to let me know if any additional info is needed! Thanks!

$0 = 255 (Step pulse time, microseconds)
$1 = 255 (Step idle delay, milliseconds)
$2 = 255 (Step pulse invert, mask)
$3 = 255 (Step direction invert, mask)
$4 = 1 (Invert step enable pin, boolean)
$5 = 0 (Invert limit pins, boolean)
$6 = 1 (Invert probe pin, boolean)
$10 = 255 (Status report options, mask)
$11 = 2147483.648 (Junction deviation, millimeters)
$12 = 2147483.648 (Arc tolerance, millimeters)
$13 = 1 (Report in inches, boolean)
$20 = 0 (Soft limits enable, boolean)
$21 = 0 (Hard limits enable, boolean)
$22 = 0 (Homing cycle enable, boolean)
$23 = 255 (Homing direction invert, mask)
$24 = 2147483.648 (Homing locate feed rate, mm/min)
$25 = 2147483.648 (Homing search seek rate, mm/min)
$26 = 255 (Homing switch debounce delay, milliseconds)
$27 = 2147483.648 (Homing switch pull-off distance, millimeters)
$30 = 2147483648 (Maximum spindle speed, RPM)
$31 = 2147483648 (Minimum spindle speed, RPM)
$32 = 0 (Laser-mode enable, boolean)
$100 = 250.000 (X-axis travel resolution, step/mm)
$101 = 250.000 (Y-axis travel resolution, step/mm)
$102 = 250.000 (Z-axis travel resolution, step/mm)
$110 = 2147483.648 (X-axis maximum rate, mm/min)
$111 = 2147483.648 (Y-axis maximum rate, mm/min)
$112 = 2147483.648 (Z-axis maximum rate, mm/min)
$120 = 2147483.648 (X-axis acceleration, mm/sec^2)
$121 = 2147483.648 (Y-axis acceleration, mm/sec^2)
$122 = 2147483.648 (Z-axis acceleration, mm/sec^2)
$130 = 2147483.648 (X-axis maximum travel, millimeters)
$131 = 2147483.648 (Y-axis maximum travel, millimeters)
$132 = 2147483.648 (Z-axis maximum travel, millimeters)