Welcome to Our Community

Some features disabled for guests. Register Today.

Grbl Error: 20

Discussion in 'CAM' started by Jesse Hanna, Nov 18, 2021.

Tags:
  1. Jesse Hanna

    Builder

    Joined:
    Nov 18, 2021
    Messages:
    5
    Likes Received:
    1
    I'm testing my new machine and learning about it. I generated my toolpaths using Qcad and exported a gcode file. Then I opened the file with Open builds control software. Everything seems normal until I run job. I get an error message Grbl Error: 20 - Unsupported or invalid g-code command found in block [ N30 T1 M6 ]. It shows up on line 3. If I delete the command, the job will run. I did a test without a bit to see it's travel. It appears to be cutting at a much reduced size scale. For example, a 2" square is cut less than .5".

    I used the G-code (Offset) [in"]setting in my Qcad/cam. I tried other settings also. I tried a 2" square to see if a basic shape would work. No luck. What's the deal?
     
  2. sharmstr

    sharmstr OpenBuilds Team
    Staff Member Moderator Builder Resident Builder

    Joined:
    Mar 23, 2018
    Messages:
    2,030
    Likes Received:
    1,428
    T (tool change) is not a valid grbl command. Find a post processor that is for grbl. (refer to the grbl wiki for valid commands: Grbl v1.1 Commands · gnea/grbl Wiki)

    For the size, did your gcode have an G20 command at the beginning? If not, its cutting in mm, not inches.
     
  3. Jesse Hanna

    Builder

    Joined:
    Nov 18, 2021
    Messages:
    5
    Likes Received:
    1
    Here's what it looks like regarding the g20 command. does it need it once at the top or more? IMG_1318(1).jpg
     
  4. Jesse Hanna

    Builder

    Joined:
    Nov 18, 2021
    Messages:
    5
    Likes Received:
    1
    I figured it out I think. I won't be able to use Qcad/CAM. looks like I have to use a program compatible with your controller.
     
  5. Peter Van Der Walt

    Peter Van Der Walt OpenBuilds Team
    Staff Member Moderator Builder Resident Builder

    Joined:
    Mar 1, 2017
    Messages:
    13,753
    Likes Received:
    4,070
    You need a Grbl compatible CAM or Post. See the software section of docs.openbuilds.com
     
  6. sharmstr

    sharmstr OpenBuilds Team
    Staff Member Moderator Builder Resident Builder

    Joined:
    Mar 23, 2018
    Messages:
    2,030
    Likes Received:
    1,428
    Once. That tells the controller that all coordinates are in inch mode until a G21 command is issue in which case it switches to mm mode. Does the qcad GRBL(offset)in post not work?
     
  7. Jesse Hanna

    Builder

    Joined:
    Nov 18, 2021
    Messages:
    5
    Likes Received:
    1
    I tried the GRBL(offset)in post and it still had unsupported commands
     
    sharmstr likes this.
  8. David the swarfer

    David the swarfer OpenBuilds Team
    Staff Member Moderator Builder Resident Builder

    Joined:
    Aug 6, 2013
    Messages:
    3,239
    Likes Received:
    1,815
    I have just run gcode I created in Qcad using the GRBL inch and GRBL mm posts through OpenBuilds CONTROL without errors.
    What GUI are you using?
    Are you SURE you selected the GRBL posts, it is easy to select the generic G-code posts instead as the Qcad interface is not very clear.
    Also note everytime you change post selection you have to recreate the toolpaths.
     
    sharmstr and Peter Van Der Walt like this.
  9. Jesse Hanna

    Builder

    Joined:
    Nov 18, 2021
    Messages:
    5
    Likes Received:
    1
    I'm using Carvco now instead. I like it. I still prefer to draw with Qcad but I just open my drawings with carvco and spit out the job.
     
  10. Douglas Smith

    Builder

    Joined:
    Feb 5, 2022
    Messages:
    6
    Likes Received:
    1
    Thank you So Much. I would have responded sooner but I've been out in the shop having a blast.
     
    Peter Van Der Walt likes this.

Share This Page

  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.
    Dismiss Notice