Our 1390LC Laser Cutter

  • Design Lab

    A straight up shout to @pierre and @Grant-Fraser for their work on the laser - thanks, you guys. It was super to see Corey Doyle making his deadline for the Warmachine World Championships and, more locally, Susan Knox from the arts council children’s festival this weekend making hers.
    What a machine - thanks to all who have made that capability happen for the Space.

  • 3D

    It sounds like the laser cutter is up and running. Are there any changes to the operations that we should know before we set to cutting?

  • Yes, the water chiller pump isn’t automatic.
    1 plug in the water pump. Cord is beside AC
    2 power up AC. Control box is hanging from the shelf. Don’t put your fingers on the back of it.
    3 power up laser
    4 power up exhaust fan. If you’re cutting plastic please leave the van running for 10 or 15 minutes after you’re done cutting to get more smells out of the room. Leave it running between cuts.

  • 3D

    @Grant-Fraser Thank you! A new protractor for a new school year is on its way :)

  • The new tube appears to be more efficient than the old one. They tell me it’ll get much longer life if we keep it below 16mA. Cory’s been cutting 4.5mm acrylic at that power without difficulty. If you’re finding it hard to cut at that power level, please let me know so I can check mirrors and alignment.

    I’m going to try to order the needed sensor to measure power at each mirror and keep records.

  • This changes everything. I needed to cut a rectangular recess to adjust the latch on the wood shop door. Making it fit tight for winter. I’d been putzing around with a chisel and a forstener bit when I realised that we have a damn laser cutter.

    I don’t need more than a quarter inch or so recess in a three quarter inch spacer… So I can laser it and pop out the piece with a chisel. I focused about 3mm into the 19mm birch ply scrap I dug out of the bin, set up my cut at 3mm/s 45% power. It ran at about 16mA as expected… And I’ll be damned if it did not laser all the way to where the last ply was barely holding it together… A quick tap with my pocket knife and the rectangle dropped neatly out of the part. We can cut three quarter inch ply in a single (slow) pass.


  • Classroom

    @pierre, OMG really? We need to get onto controlling the Z axis dynamically

  • Classroom

    @pierre, or even statically with some test cuts. We should grab a depth gauge and see how far we actually cut at a pass of say 25 mm/s at “full” power (i.e. 16 mA or w/e).

    If we did a few quicker passes and adjusted the laser focus in between, we may be able to get a cleaner cut without adding on much time, and help punch out the back. 3/4" is much wider than the plane of focus of the laser, so what we are losing in cutting efficiency, we are making up for in brute force by slowing the laser down, so it may not even necessarily take longer in the long run. Without automation for this in the software, we would have to make some adjusted focusing jigs based on the depth actually cut with a standard speed and power pass (would need different jigs for different materials).

    It would be cool to play around if you have something that could measure the depth of cut accurately.

  • @kile right after three rotary cutter, my next upgrade is a more versatile controller… Call it “advanced mode” if you will… I’d like to have a tested plug-in replacement for the current controller that runs on standard g-code running by mid winter. From there I can make the z-axis move dynamically, mostly so I can vary the kerf of my cut on the fly by changing both z-height and either speed or power at the same time. I want to do some vector calligraphy… I see no way to make the controller on there do that, and a working spare as an upgrade seems like the way to go.

  • @kile said:

    It would be cool to play around if you have something that could measure the depth of cut accurately.

    I will bring in my Mitutoyo depth micrometer, it’ll measure to 1/1000" easily. I need to use it to make a new power/speed/depth board anyway.

  • Design Lab

    @pierre this will allow acrylic ‘oragami’ as well??? cooool

  • @Vaughn Yes, I’m not sure how it would know how long it needs to laser to get the desired bend though? The g-code could certainly tell it to drop the Z by a certain amount (the wider kerf would define your bend radius?), set the power and cutting speed to specific values and make a certain number of passes, but I think you’d need to trial and error how many passes to make?

    I’d be tempted to design a laser-cut fixture that the part folds around to make critical bends. Super interesting stuff.

  • Design Lab

    @pierre no prob on the settings for a fold line as opposed to a cut line - 30 mins trial and error with each thickness of acrylic will do it - preassign a certain colour of line to that parameter and voila. Actually, it was making the makerspace shop signs with the out-of-focus pin-stripe pass that showed the out of focus potential to me.

    And yes, this is a very, very interesting sub-topic; the Blender sculpture concept would be taken to a whole new “how the hell did he do that???” level.

  • Laser is back online. 475 hours on the clock with a brand new tube. Per tube makers recommendations we tilted the tube mounting brackets to make air bubbles evacuate more effectively then realigned the mirrors to put the beam back where it needs to be. Machine was thoroughly cleaned and many test cuts were made. Beam appears to be diverging slightly in the y plane, we will likely do some more aiming to try to correct it, but in principle it is cutting ply again and getting fairly tight kerfs.

  • @pierre Mmmmm, I love my kerfs tight…

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