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Laser Training: First Class

Whiteboard Lecture

  • Explain svg versus bitmap.
  • Laser cutters won't engrave a jpeg.
  • Explain need for .dxf format, or AI with compression off
  • Explain cutting versus engraving from a closed line POV

Laser Hands-On

  • Show how to import dxf file and set color/layers
  • Demo the startup steps from wiki.
  • Show scrap bin. Talk about materials.
  • Explain banned materials and MSDS.
  • Demo importing .dxf into LaserCut and make a piece. Using a simple example .dxf file previously prepared. Show how files get into workstation.
  • Let each student in turn go from "cold machine" to finished piece.

Notes from Nate(tm)

The basic ideas are this: The "happy path" of operating the machine is pretty straightforward and you can get it from watching youtube or watching other folks use the machine. To me, that's not the point of training, everyone should do those things *before* coming to get certified. The point is to *stay on* the happy path, by outsmarting the machine's incessant attempts to destroy itself, and to respond quickly and appropriately if something does go wrong. Ergo, understanding the numerous ways the machine can fail (assumptions and when they're not valid, mechanisms and how they work, etc) is the point of training. Also, understanding when you're in over your head and the most appropriate response is "shut it off, tag it out, and ask for help".

So, in that spirit, I recognize that I also have points of failure -- I'm a forgetful human, especially when I'm excited about something (and lasers are exciting, and I tend to use them for projects I'm excited about), so I wrote myself a checklist (it's in the wiki page) that I follow like a pilot's pre-flight checklist, to make sure I cover my bases every single time and don't get complacent. Side note, there's a bit of traditional wisdom in fire and electrical code circles, that every line in the code is there because of a fatality that happened in the past. Likewise, every line on the checklist is there because of a failure it prevents.

So with that in mind, I teach to the checklist. First, rehearse the motion, build the muscle memory. Physically find and touch and do the thing -- I never demonstrate stuff unless my student is unable to figure it out at first, and even then, I make sure they go back after me and do the thing, and do it properly. Second, explain why it's there. Figure out what would or could happen if that step was missed, and why it's important. Third, explain how to recover if that thing happens anyway.

If we can make our way down the list and they have a solid understanding of every step, then I consider 'em safe to solo on the machine. We do an end-to-end rehearsal as I watch 'em run a job from start to finish, and call it a day. (I should clarify, above when I say "explain", I mean the student explaining it to me. I'll lead 'em along the logical path if needed, but I'll make sure they take each step to put together the cognitive chain.)

2nd training

Tell me all the ways that you can break it.