DXF curves jerky 1.1f CNC Z-XY



  • Hi Zax,
    Just started doing some DXF work since loading the 1.1f CNC Z=XY firmware I needed to add Z homing. I notice now that all curves on DXF files or vectors that have been traced by T2 are jerky. Straight lines ok. It's like it isn't joining segments together. A quick reload of 1.1e without changing anything and the curves are back smooth. Back to 1.1f CNC Z=XY and the curves are jerky again.

    Any thoughts?

    Cheers

    David


  • Developer of T2Laser Software

    @DavidF The parameters for my Grbl 1.1e Default are setup for a laser, compared to the CNC firmware which is for a spindle, it's simple to change in the menu.

    Use "Send Default Parameters" from the Machine menu after loading the CNC firmware, and also select "Laser Mode" from the Settings / Advanced menu.

    You may need to change the Z acceleration parameter $122 for smooth operation, it will depend on the motor and axis gearing.



  • Hi Zax, Just to be sure you understand, it's the X and Y that are jerky, not the Z.
    It seems to be trying to plot each segment of a curve individually rather than trace a line. It's almost the decoding of the DXF is different??

    Hope that makes sense.

    Cheers

    David


  • Developer of T2Laser Software

    @DavidF Yes, I get what you are saying. Did you try loading my default parameters?



  • I did do that when I first installed 1.1f, but I'll try again tonight.

    Thanks Zax


  • Developer of T2Laser Software

    @DavidF If you are sending the same G-code then the only explanation is the Grbl parameters, since the CNC version expects a spindle and not a laser (by default) it makes sense you would need to change the parameters and enable laser mode to get the same result.

    If after doing these 2 things it's still different then we will have to dig deeper into how that could happen.



  • Hi Zax,
    Yes it was the same file, and I tried laser mode on and off with the same result. But I will try again and see if I can pin it down a bit more.

    Cheers

    David



  • Hi Zax, a bit more info. The jerkiness only happens when CNC mode is selected in the main page settings menu for cutting. With or without laser mode selected. In "normal" engraving operation all is fine and the curves are smooth.With 1.1e it's ok in both engraving and cutting modes.

    Hope that helps.

    David


  • Developer of T2Laser Software

    @DavidF Is this a laser or a CNC? If it's a laser, you need to select Laser Mode.

    0_1539629041186_upload-9b67369b-40d6-4b70-a9b8-ffa36b06b1e6



  • Is the elekmaker A3 laser with the optional Z axis. I fitted homing switches to XY and Z. You suggested I need the 1.1f CNC Z-XY firmware to home Z. The operation I am trying to do is cut through thicker materials using your depth change / pass option. For this you need to have CNC mode selected (with laser mode on). It is in this mode that the XY is now not following a smooth curve on a DXF. Your firmware 1.1e works fine. (but obviously doesn't home the Z)

    I hope that all makes sense?

    Cheers

    David


  • Developer of T2Laser Software

    @DavidF You have confirmed laser mode is enabled in BOTH places?

    above picture and on the laser controller...
    0_1539697543620_upload-b797459b-707c-4f88-919d-ccb295b5a048

    The firmware should be the same in this case. I run this one on my CNC and haven't noticed any difference in the paths.

    When you say "jerky" are you saying it's pausing at nodes / segments or is it like the resolution is lower for the path so it's drawing a circle as distinct lines and not smooth curves?



  • Hi Zax, confirm laser on in both places.
    I just checked using your sample 50mm circle and the effect is the same. It is drawing the circle as very small segments rather than a smooth curve. Only in CNC mode and only with 1.1f CNC Z-XY. simply changing to 1.1e without changing anything else and it's fine.

    Hope you can get to the bottom of it!

    Cheers

    David


  • Developer of T2Laser Software

    @DavidF Check your Grbl parameters, in particular $12 arc tolerance. It should be 0.002 (mm).



  • Hi Zax, it was 0.02mm. I changed to 0.002mm, but the result was the same. Still not smooth.

    Cheers

    David


  • Developer of T2Laser Software

    @DavidF This is really weird, there shouldn't be anything different between Grbl 1.1e and Grbl 1.1f that would cause jerkiness. I think the motion planner is the same code.

    Is the actual output different, can you visibly see it or is it just acceleration / deceleration on the vectors that is making it appear jerky? That may just be Grbl parameters, although using my send defaults should have made them identical.

    I'm not sure what else to try at this point, perhaps compile the latest Grbl 1.1 release with Z-XY homing enabled.



  • Agree not sure where I can go from here except to compare the parameters between the two versions. I would certainly like to keep the Z homing for sure. I'll try turning the laser right down so it it simply draws on paper and see if I can see the difference that way. But the movement is very noticeable on the curves.



  • Hi Zax

    Now we have a worse situation!
    I did compare the 1.1e and 1.1f CNC Z-XY gbrl parameters and there are no differences at all. I made sure that after loading each firmware I loaded the defaults and they are the same.
    Bigger problem is that as a test I loaded your 1.1f XY home firmware, and got a sync error at the end. However the firmware seems to have loaded. The big problem now is I can't load any other firmware. I just get a failed to load 1/1 error and the firmware has not changed. The main DOS box closes after a second, and another empty one pops up followed by the error. Of course it's not got the firmware to home the Z, AND it has the same problem as the CNC version - Jerky curves.

    I have the 3 axis mana board and there is no reset switch on it to press, and removing power doesn't help.

    Any advice on how to recover this situation??



  • Ok, I replaced the nano with the old one from the original board and we are back to sq 1. Can load firmware now. I have a spare Arduino uno, so I'll use that to reload the boot loader later.

    So we are still left with 1.1fCNC Z-XY as suspect...


  • Developer of T2Laser Software

    @DavidF Do you know how to compile and load your own firmware using Arduino IDE?



  • Yes. I have written code for Arduino on other projects. What do you suggest?


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