​When using Linux EMC I could easily drive a laser from the direction pin of the Z axis on the parallel port.The pin held it last state so if the last movement commend was down it stayed that way even as the other axis' were moving. All I had to do was wire that to the laser enable lead.

When I switched to GRBL I found the dir pin always reset to up whenever another axis moved. this strange interaction did not affect the stepper because there were no pulses on the step pin. all that was needed was a simple d flip flop to keep the state. it turns out a 12c508 pic micro is cheaper than a d flip flop....

Step 1: Assembly

I added a bi color led so i could see the laser status without having the laser connected. then I added a 3 pin jumper to select direction pin polarity.

if you are using a dedicated laser engraver this wouldn't be necessary as you could change the polarity of the pin in software. I use my machine for both laser and milling/engraving so I wanted an easy way to match it to the setup of the z axis of the mill.

I have used this circuit with a 2n2222 to drive a mechanical relay, with a 2n2222 pulling a p-channel mosfet, and with a solid state relay. the method you choose depends on your laser system.

<p>Is this something you've made in another 'ible? It looks cool, I guess I just don't know enough about what you're talking about...nice documentation, though!!</p>
<p>thanks. its an addon to the cnc machine i made last year. that one is here </p><p><a href="https://www.instructables.com/id/3-Axis-Arduino-Based-CNC-Controller/" rel="nofollow">https://www.instructables.com/id/3-Axis-Arduino-Bas...</a></p><p>i <br> wanted to laser engrave cork coasters and wood plaques. maybe try <br>leather too. kind of like the old woodburning kits they used to sell but <br> using hitech parts instead of a soldering iron. i wish I had more time <br>to play with this stuff</p>
Maaaaan don't we all. I'd love to build my own CNC machine.

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