LR3 CNCjs questions

LowRider CNC Troubleshooting
1

I finally have my LR3 working good mechanically. I have drawn the crown and simulated some test cuts from the display screen. I am now trying to use CNCjs to complete my workflow to surface my spoil board and am running into some confusion over how CNCjs operates.

Probing: does it not work correctly? I can enter G38.2 Z0 in the terminal window and it works fine but if I use the probe button from the CNCjs interface it does nothing. The settings are on G38.2 button but when I click on it it doesn’t move. I know I can set up a macro button to do the same thing but it would be nice to use what’s there.

Starting a cut: after I upload a file and hit the play button the Z axis drops to the bottom and keeps driving. The file is fine from the LR3 display so in theory it should work or is there something I am missing in CNCjs?

And lastly, not really related to CNCjs but is there a probe command on the LR3 display? I am using the monochrome display with the Rambo board. I think I looked at everything but didn’t see anything that said “probe”.

2

To stop mine from doing that I had to add G92 X0 Y0 Z0 at the start

3

So that confuses me and I took it out of my g-code. If I zero out Z by either probing or using the paper method, then raise the tool up a little so I can start the router wouldn’t having this in the g-code re-zero Z at the now raised point?

4

Yes. I home XYZ manually then jog it to where I want it to start from then it thinks that’s the 0 for the file it’s cutting

5

So you start the router, then jog it to your start point, then it gets the G92?

6

Remove just the Z0 on the end.

Here’s the setup steps I use.

Manually Jog to where I want the X0Y0 to be.
I use a touchplate to set my Z0, but you can use the paper method if you want.

Then, my gcode has a G92 X0Y0 as the first line. This sets just the X and Y zero point, but doesn’t modify the Z0 point.

7

Ah, that makes more sense. I’ll give that a try.

8

So I just tried it with the Z0 removed from the g-code. Here’s the beginning of the g-code:

; mode: surfacing
; rapid feedrate: 3000 mm/min
; raise/lower feedrate: 800 mm/min
; pen down z level: -0.5
; pen up z level: 0.5
; drawing feedrate: 2500 mm/min
; x extent: 200
; y extent: 400
; stepover: 12 mm
; direction: N
; perimeter: false
G92 X0 Y0
G0 Z0.5 F800
G0 X0.000 Y0 F3000
G1 Z-0.5 F800
G1 X0.000 Y8.163 F2500
G1 X0.000 Y16.327 F2500

I don’t see anything there that would cause Z to drop.

I am using the G-Code test pattern generator at G-Code Test Pattern Generator
to test surfacing patterns to make sure I understand what it’s going to do before I start actually surfacing my spoil board. If I run this code from the LR3 display it works as expected. When I run this from CNCjs it drives Z down and doesn’t stop until I kill power. I must have something not set up in CNCjs correctly.

I have this set up in a machine profile in CNCjs settings. I wasn’t sure what to put in for Z limits so that may be way off:
image

9

I think I have it working now. Still not sure what was causing the drop.

10

That should be raising your Z 0.5

That should be dropping the Z.

The F### on the end of each line is the Feed speed for that movement.

If I remember all the commands correctly, I’d expect to see the mill move up, move down, then move in the Y direction. I don’t believe the G0 X0Y0 will actually do anything since the G92 command just set the current location to 0.

11

The Z limit should be the max height your machine can lift Z before hitting an endstop. It’s kinda like a software limit switch.

12

Yes, that’s what it is doing when it starts correctly. It seems to be working fine now that I have removed the Z0 from the start code. I am currently surfacing the spoil board and so far so good.

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