Ask Grbl CNC questions here.

Very new to this and could use some tips troubleshooting. Installed a port of grbl called grbl-polar, for running a vertical plotter. Software seems to be running happily on the arduino, I can see it running and can change settings in OpenbuildsControl, but the cncshield, drivers, and steppers is completely unresponsive. I have checked that hardware works by running this sketch, and it spins the steppers fine. GitHub - makertut/cnc-shield-v3-uno (via ).

Wondering if I am missing something completely basic, like enabling a pin by shorting some of the pins on the shield, but can't find any documentation about it.

Do I have to change something in the grbl settings on the arduino via serial to get it running, or is it supposed to be plug and play? The only setting grbl-polar mentions is to use $27 to input width (the space between the two steppers).

The grbl port is based on v 0.9 and is hosted here: GitHub - ilaro-org/grbl-polar: Modification of grbl that provides motion in polar coordinates and other features for our graffiti machine. Grbl is open source, embedded, high performance g-code-parser and CNC milling controller written in optimized C that will run on a straight Arduino

Arduino Uno: Atmega328P
Cnc shield: Protoneer v 3.0 (should support grbl v 0.9)
Drivers: DRV8825
Motors: Nema 17.

 

Hm. i stried x10 y10 and suddenly I got movement. I also found a newer port of grbl, and after installing that I could use the arrowkeys in openbuildscontrol. I seem to have an another issue in that the steppers seems to move in tandem and only in one direction but at least it is moving! (new port is at GitHub - dpenney/grbl-1.1-polr: Upgrade of https://github.com/ilaro-org/grbl-polar to use GRBL 1.1. grbl-polr adds support for motion in polar coordinates for V plotters. Grbl is an open source, embedded, high performance g-code-parser and CNC milling controller written in optimized C that will run on a straight Arduino https://github.com/grbl/grbl/wiki for those interested).

 

Hi there.
I have a work offset question.
I'm used to using industrial Fanuc and HAAS machines where it is relatively easy to set your work offsets. You basically jog to any location,. hit your position button, grab the the machine coordinate value, plug it into the offset table and bam, you're done. This procedure is exactly the same for for any location you wish to reference.

I know how to home my machine.
I can set up G54
I can turn it off again and find my G54 again...
I know how to type G90G54G0X0.0Y0.0

How do I set up and store Any other random offset location?? not talking about a G10L2P2 shift that I cant get to work. Maybe I read the tutorial wrong

Is it possible to job to any random location on this machine and store it as any location offset?

Also are there plans in the future to enable tool diameter offsets?

 

Try using L20 rather than L2 - sets the current position as zero for the wcs selected by the P parameter.
Alex.

 

What Software is that you are using in the picture? I see that you have options for multiple work offsets? I need that!!!

 

Ok, I did try that. Here is what it does when I do. ... So I jog to a location. I use the buttons to zero the controller as X0.0 Y0.0. This sets my G54..

I then jog in Y where ever. Then type G10 L20 P1, ( which is G55 I think) I thought this command set the parameter for the new location as G55.
My positional display now reads X0.0 Y0.0 ok something happened here. It reset my numbers . Great. I have played with a few commands that alter the work coordinate location, but they always just update the main work coordinate.

So I then type G90 G0 G54 X0.0 Y0.0 and ....nothing. The machine thinks it is where it is supposed to be.

Here is another one,
at work I have used G92 occasionally. The way it is supposed to work is that you jog to a location Set your G54 , after that, type G92G0X10, Y5.0 and it will go an incremental distance from where you just were. The open builds controller just resets the numbers for X and Y in the controller to what you just typed in hence g92 G0 X10.0 Y 5.0 and does not move. Some help here please

 

P1 is G54
G91 is incremental, not G92. If I recall correctly G92 sets a temporary home position - in the Machine co-ordinates system.
If you want to move while in G54 just type G90 G0 Xn Yn (where n is the absolute position relative to G54 X0,Y0 or G91 G0 Xn Yn where n is the distance you wish to move) Remember G90 and G91 are modal, so once used they remain in force until you change them. Personally I only use relative mode movements for things like probing macros and I try to be rigorous about setting absolute mode at the beginning of job files and at the end of macros.
Alex.

 

Thanks for the response. Can you tell me how to set a G55?

 

What cad/cam software are you using? If Fusion 360 then the Openbuilds post processor for grbl has multiple wcs.

docs:software:fusion360 [OpenBuilds Documentation]

Alex.

 

G10 L20 P2 will set the current location as G55 wcs zero. You might need to add X0 Y0 Z0 to the end of that - I'm not sure if grbl actually requires that or not.
Alex.

 

Thanks for your help with that. I believe it was the way I was using the controller. before didn't have a good grasp with the Serial Console and how it functioned. I have them all working now!! Even did a power shutdown verification.

 

GrblGru “Grbl not found @ COM5” HELP!

I am able to program my Arduino MEGA with IDE, no problem with Grbl 5x. But when I try to connect to the board in GrblGru it says "Grbl not found @ COM5". I can't figure out what the issue is but I think it has something to do with the COM port already in use. I am able to make all this work on my Arduino UNO but not the MEGA.

Any ideas as to why GrblGru can't see the program on my MEGA?

Thanks

 

I have a question if you are still open to answering questions....

What is the best way to isolate an Arduino NANO that is running GRBL from the computer that is connected over USB?

I am running into a problem where I have a homegrown CNC plasma cutting system that is powered by a NANO with GRBL 1.1. I am using GSender that runs on an intel compute stick. The NANO is powered through a separate OMRON DIN mount 5v power supply. The compute stick has a 2.4 amp 5v power supply and its hooked to a powered usb hub. The usb hub has a wireless dongle and the connection to the nano. the usb hub has its own 2.4 amp 5v power supply.

The problem is that when I run the CNC the intel compute stick hangs and gets really sluggish since it is just a serial over usb connection, I am lead to beleive its hanging because something is drawing too much power.

The reason I am using an intel compute stick is because a while back I had an issue with electronics (lack of grounding I think) which fried a lot of stuff including the USB components inside my (previous) laptop. Now that I have purchased a new laptop I'm rebuilding everything but using the compute stick as a means to isolate my laptop through the wifi connection.

Is there a better way to do this?

 

Hello,
Is there any option in OpenBuild software to change the buffer size of command streaming?
I'm trying to send the Gcode line by line.
laserGRBL software has an option to do so by "Synchronous Mode" which GRBL waits for Gcode execution.
Regards

 

Dear Peter,
Thanks for your reply
In my CNC machine, with mks boards, USB (sending the Gcode through PC) conflicts eith TFT touch screen controller, with invalid gcode id: 25 & 24.
That's why I'm trying to send Gcode line by line to solve the problem.

 

Hey guys, I'm having a strange issue with running GRBL from an arduino uno on my laser cutter that I just can't seem to resolve and am wondering if anyone has any ideas.
I'm running it in CoreXY mode, Grbl version 1.1h and using LightBurn to control it. When sending a gcode it moves quite slower than the speed I input.
eg. I make the machine move 1000mm at 1000mm/m speed, it will take 1 minute and 20 seconds instead of 1 minute. Another point is that if I run a G0 move or travel, it will go at exactly the speed it set it to, it's only with a G1 command where it is slower. The machine moves exactly the correct distance so I don't believe my steps are an issue. It's running in 1/16 microstep mode and I've tried others but they result in the same issue

These are my current settings if that helps, everything else is default in the config except it being in CoreXY mode

$0=3
$1=25
$2=0
$3=0
$4=0
$5=0
$6=0
$10=0
$11=0.010
$12=0.002
$13=0
$20=0
$21=0
$22=1
$23=0
$24=200.000
$25=3500.000
$26=250
$27=1.000
$30=1000
$31=0
$32=1
$100=200.000
$101=200.000
$102=200.000
$110=10000.000
$111=10000.000
$112=10000.000
$120=2500.000
$121=2500.000
$122=2500.000
$130=500.000
$131=300.000
$132=50.000

Any input would be greatly appreciated as I've been stuck on this for a while, Thanks all.

 

Thanks for the response,
I feel like the acceleration I have is plenty though to get up to speed? And the fact that a G0 move goes at 1000mm/min perfectly shows the laser cutter is capable of that speed.
Is there a way I can add an offset value or compensation maybe to get it to actually be 1000mm/m if that's what I type into lightburn? I need the speeds to be accurate sadly.
Thanks