Monday, 13 January 2014

axCut Laser Cutter - first cuts; not quite epic fail

We have cutting!  and a lot of smoke - really must order the cladding and setup some extraction!  This is a proper "Tomorrows World" video, it doesn't quite go to plan, but nonetheless - there's definite progress:

The cutting paths were generated from SVG via a little converter program I wrote using the paper.js library.  The arduino/Marlin combo is processing the bezier curves (as demo'd in previous video), but now with the addition of laser on/off commands around each path.  Air assist working nicely, except when the airline is being burnt by the laser :(

Laser control and watercooling all working well - the watercooling pump runs continuously, but the radiator fans only kick in when the laser outlet water temp rises above 22 degrees C.  The watercooling system is very quiet, thanks to the excellent little pump (Phobya DC12-260).  The fans are also extremely quiet when they are running, but the water temps haven't gotten above 19 degrees as yet (ambient temp during testing was just under 18, thanks to doors/windows being open for the smoke).

Laser control commands include arm/disarm of the laser PSU, control of laser power (0-100%), laser on/off and a diagnostic output.  The laser power control is via high speed PWM (62KHz, using timer4).
Air assist will soon be integrated into the relay module, so it can controlled by the arduino (via a couple of G-codes).

Air assist clearly plays a big role in:
 - stopping fires!  (without the air assist, there's a persistent flame about the cutting point)
 - keeping crap away from the lens

I'm assuming cut quality will get much better once the honeycomb bed is installed (so smoke/heat isn't being contained under the work) and once the focal point is properly calibrated.  I did go on to adjust the bed and do some power/feedrate tests, some of which you can see in the video below.  After bed adjustment, the cutting kerf at optimal power/feedrate is approx 0.2mm... should still be able to get better than that.  There is also quite a bit of scorching around the cut line, hoping the honeycomb+air will dramatically reduce that.

 - Order cladding
 - Install honeycomb bed
 - Finish wiring z axis
 - Calibrate focal point
 - Solve raft of pronsole errors when sending complex jobs - presumably some errors in my firmware extensions
 - Integrate air assist line into axes (i.e. an x-axis cable chain)
 - Design/order/build decent trolley


  1. How hard would it be to modify the design for 40x40 mm extrusion? I have a source in the USA with a large amount of that size for $2.49 a foot.

  2. relatively straight-forward - although many parts are optimised for 6mm slot, so there would be quite a few changes to make in the openscad source.

  3. Would you, Could You PLEASE share the designs for you various brackets / clips / mounts for the rail?

    1. the complete design is on github:

      if you just want the finished parts, look in the stl directory

  4. nice blog videos make it very attractive and impressive can you share more about CNC Laser Cutting Services