XYZ Plate Start Gcode Troubleshooting

LowRider CNC Troubleshooting
1

I recently bought and XYZ probe and am having trouble getting it to work on an SKR based LR3.

s-l1600
s-l16001104×1128 238 KB

The sample start code is as follows, with my comments added.

G38.2 Z-15 F100; Probe  Z Target -15 
G92 Z3; Set Z to XYZ plate thickness
G91 G0 Z3; Raise Z 3mm
G91 G0 X-27; Move Left -27mm
G91 G0 Z-6; GO to Z0
G38.2 X15 F100; Probe X Target Right
G92 X-12.18; Set X0 to X offset (9mm + half bit diameter 3.18 for 1/4", 1.6 for 1/8" .8mm for 1/16")
G91 G0 X-3; Move Left 3mm
G91 G0 Y-27; Move Forward 27mm
G91 G0 X27; Move Right 30mm
G38.2 Y15 F100; Probe Y Target
G92 Y-13.175; Set Y0 to Y Offset (9.2+ half bit diameter 3.18 for 1/4", 1.6 for 1/8" .8mm for 1/16")
G91 G0 Y-3; Move Forward 3mm
G91 G0 Z30; Move up 30mm

This code will probe z, but will start the gcode file immediately after. Is something wrong with using G91 in the context? Im really confused here.

2

Put a single G91 at the start, and change all of the G91 G0 commands to just G0 commands.

(I don’t think that G91 G0 xxx is a valid command).

Remember to go back to absolute mode (G90) at the end, otherwise your subsequent commands may not be what you want.

1 Like
3

I agree, G91 on each line is messing things up. I see a few other potential gotchas:

This is going to scrape the bit on the workpiece. Probably want something more like Z-5.

This is still relative, so it is moving right 27mm, not 30.