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Setting up for new laser machine

RalphF
2016-01-17
2016-01-18
  • RalphF

    RalphF - 2016-01-17

    I purchased a low cost laser machine with a 2.5 watt laser head. How can I configure PyCAM to be able to work with this 'new' laser machine? What settings must I change or do I create a new laser config file?
    Thanks...

     
  • Lars

    Lars - 2016-01-17

    Hi Ralph,

    PyCAM generates GCode. Depending on your specific Laser you may need to modify the resulting GCode a bit. Probably you will need to replace "Start Spindle" and "Stop Spindle" with commands for starting and stopping your laser.
    But maybe your laser controller board already does that for you?
    Lars

     
  • RalphF

    RalphF - 2016-01-17

    Thanks for the quick reply. I'm trying to find out if my controller board does that already but I have not confirmed it yet.

    I think I will also need a way to control the laser power setting. This is done by setting the voltage. I plan to try 90% power for cutting and 50% for etching lines in the plywood. I'm not sure how this setting will figure into using pyCAM since it has no knowledge (that I'm aware of) of lasers?

    My low cost/low powered (2.5w) laser came from China and the software that comes with it is pretty poor so that's why I'm looking around for a better software solution. I've decided to use a free CAD app that can save .stl files, then use pyCAM to generate the toolpaths and .ngc file, and then finish up using Universal Gcode Sender.

     
  • RalphF

    RalphF - 2016-01-17

    Additional Comment: As a fairly new laser user, I have been doing a lot of research online learning about how CNC operations work and what software there is to support them. Amazingly (to me anyway) there is very little support for the home/hobby market.

    Everything is CNC (Spindle and cutter) oriented. In fact, the only software that I've seen specifically modified for laser usage is Cut2D Laser but that is specifically for the Emblaser laser machine. I don't have an Emblaser so I can't get that software and it wouldn't work on my laser anyway.

    As some folks may also know, Rabbit Lasers makes the LaserCut software but that is for their specific laser machines and their machines are expensive (read: not for the hobby/DIY market).

    I'm a fair (not great) Visual Studio programmer (I don't do it as a profession) and I was looking at the HeeksCNC open source project with the thought of well, maybe I can modify it to support adding a Laser Tool and the associated settings, etc. But as I dug deeper into it, it looks like it might be a bit over my head to pull off. I sent an email to Dan Heeks about a week ago asking him what his thoughts were about adding laser support to his software, but I never got a response.

    I think I like the Three Step approach:

    1. Use any CAD software that can produce a .stl output file.
    2. Use PyCAM to create the toolpaths and generate the gcode file.
    3. Use Universal Gcode Sender to actually send the job to the laser machine.
     
    • Lars

      Lars - 2016-01-17

      (I sent my other reply before I read your additional one)

      Regarding the amount of available software for the CNC topic: I share your feelings. When I started to run my CNC mill around 2010 I was very confused by the lack of toolpathing software.
      The machine control part of the workflow is done in an amazing quality by the linuxcnc people. Toolpathing is sadly still an issue.

      Regarding the distinction between mill and laser: technically these fields are not really different. Most things can be done with software that is oriented towards CNC users, as well. Specific details (e.g. burning/etching surface patterns) are not doable at all, but cutting and single-depth etching should be fine.

       
  • Lars

    Lars - 2016-01-17

    The power setting could be done via the spindle speed, I guess. Just define two different tools with different spindle speeds. But this approach is only useable if etching and cutting paths are defined in different models, since you will need to generate two separate toolpaths.

    I do not know the Universal GCode Sender. Thus I cannot tell which part of the workflow it will conduct.

    If you are able to send raw gcode to the laser, then it should be possible to use pycam in your workflow. But since pycam is currently not actively maintained I would suggest you to take a look at possible alternatives. Somewhen there was an inkscape plugin available for generating gcode based on vector files.

     
  • RalphF

    RalphF - 2016-01-17

    "The power setting could be done via the spindle speed"

    I agree...that would be perfect.
    I guess I just didn't thinkof that...so now I guess the classic CNC world does have support for adding laser tools.

    But now, there has to be a way to configure the gcode for the laser tool. For example, yes we can set spindle speeds on a scale of 1 to 100 with 50 being 50% power, 90 being 90% power, etc. but somewhere along the way, that spindle speed value has to be translated for the GRBL board (so it can set the right level of voltage) and I'm not sure how to do that?

     

    Last edit: RalphF 2016-01-17
  • Lars

    Lars - 2016-01-18

    I do not know GRBL. I guess the users or developers of this software know better how to solve this translation.
    If everything fails: just use "sed" or any similar tool for replacing all spindle speed assignments with the corresponding laser power control command in the GCode file.

     
  • RalphF

    RalphF - 2016-01-18

    Not familiar with sed, that must be an editor callable by another application?

    Update: I just googled what Sed is.

     

    Last edit: RalphF 2016-01-18

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