Tim Hatch

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3-D Printing Lessons Learned 15 Aug, 2012

I discovered these while assembling my derivative of the Printrbot. Links go to photos that are part of the Printrbot Detail album.

  • Get enough workspace mine’s basically storage. It’ll take longer than you can just leave it on the dining table, and you’ll also want to do the trial runs outside. You don’t want melted plastic smell indoors.
  • Don’t be afraid of adding more zipties to get it to work.
  • Gen6 Electronics have a strange connector that has ramps that are slightly incompatible with the Molex KK ones I have (imagine: 3-pin fan connectors). Solution? Use Molex SL instead (imagine: motherboard speaker connector) which have more space, but are non-polarized.
  • Then you’re going to realize your wires are too short. Build some extension cables rather than trying to solder on longer wires.
  • Heated bed is a must, ABS won’t stick for me without it.
  • For Kapton tape, wider is better. I have ~1.5” and ~2” and the 2” is much easier to work with. Using a plastic card to smooth it will help prevent bubbles. I’ve heard about 8 × 8” squares, but have yet to try one.
  • When your extrusions first happen after the hotend reaches temperature, the hot end is going to rake across your tape joints, ripping them up. A partial solution is to add G-Code that moves to the correct X,Y location ahead of time, with Z up slightly while it heats, then when your program starts it will just be a Z move.
  • You’re going to make quite a few prints before you get one that works. Keep lots of notes (this is distilled from 21 pages of notes kept in Google Docs).
  • As long as your board uses a bootloader, it’s safe to try other firmwares. I settled on Marlin as working really well on my Gen6 board, which only paused on me once and handles acceleration.
  • Your accuracy will be limited primarily by your nozzle and filament size. I use 0.5mm nozzle with 3mm filament, but I know that 0.35mm should work with my hardware, and 1.75mm filament (like the Up! and some MakerBots use) would really improve things.
  • Custom endstop flags are tricky. Get some aviation snips, it’ll make your job easier.

Even with all that, my bot is still a kludge. I have lots of binder clips holding parts on, and the main board isn’t even screwed down to anything. The Printrbot isn’t a ready-to-go kit, but it may well be the best repstrap in terms of availability to print the bot you want to end up with long term.