Recently I was setting up my new mac laptop so that I could use it as a 3D printing host, I installed slic3r and pronterface, finishing up the configuration with a couple of smaller test prints. Happy days! Everything working perfectly. So I started a much larger print job, leaving it do its thing. I came back about half an hour later to see that the RepRap had “frozen”, it was still hot, but the printhead wasn’t moving. Just frozen in space, mocking me as a big plastic lump oozed out of the hotend. Why did it do that?


Turns out that my computer had gone to sleep. Doh. Pronterface doesn’t appear to keep OSX awake while performing a 3D print. So to fix this:

  • Open up system preferences (the gears icon in your dock).
  • Select Energy saver.
  • Uncheck put hard disks to sleep when possible (you will want to turn this back on again after printing so that you don’t reduce the life of your hard drives)
  • And slide computer sleep all the way over to never, as shown in the picture below: