So, found out the hard way that you can’t apply heat to neodymium magnets. Had 16 magnets to press into a print (tool holder). Thought since the soldering pen I use for inserting threaded nuts into prints works so well, I would use it for this too. And it did work well, but now all the magnets are not magnets any more. Yup, heat will demagnetize them. Part is useless, so had to trash it. Found out something new, but wish I had heard about this beforehand.

  • TootSweet@lemmy.worldEnglish
    16·
    1 day ago

    The way I’ve embedded magnets in prints in the past was to:

    • Design a magnet-shaped (plus like 0.2mm of clearance) cavity into the print, but leave it completely “closed off” to where it’s “inside” the print.
    • But only “closed off” by like 2 or 3 layers (I was printing at 0.2mm layer height for this particular print).
    • Use “pause at layer” functionality in my slicer (I used Cura at the time) to pause just before the first layer that would “close off” that cavity.
    • Start the print and when it pauses, drop the magnet into the cavity.

    Yes, I was a bit nervous about the magnet potentially jumping up and sticking to some ferromagnetic metal that’s part of the print head, but that didn’t happen in my case. YMMV, I guess.

    I guess theoretically it could also be the case that the heat from printing could weaken the magnet, but again, that wasn’t an issue in my case.

    Just to elaborate on what my project was, I had a freely-spinning part that I wanted to be able to fix in place or unfix. I fashioned a “stop” that when engaged would fix the freely-spinning part in place. The way it works is that the stop can move freely up and down. Putting it in the “down” position fixes the freely-spinning part in place and gravity keeps it engaged. But to disengage it, you slide it straight up. At the top of the “track” in which it slides is where I put the magnet. I used the same technique as described above to embed a little stack of about four staples into the stop itself. So, by sliding the stop to the top of the track, the magnet attracts the staples, keeping the stop disengaged until you pull it back down again to where gravity will keep it engaged until you move it back up.

    • RecallMadness@lemmy.nzEnglish
      11·
      1 day ago

      If you do this, make really good notes and markings on the polarity of your magnets.

      The number of times I have tried this, to end up with two mating parts that repel each other.

      Alternatively, just print recesses and glue them in afterwards.

      • Munkisquisher@lemmy.nzEnglish
        3·
        20 hours ago

        I just stack the magnets first to get them all in the same polarity, and insert them, using the stack to push it into the hole, with a press fit they won’t jump out

    • RattlerSix@lemmy.worldEnglish
      5·
      1 day ago

      I’ve used a lot of 12x3mm and smaller magnets without them jumping up and attaching to the print head but I did have it happen with larger 40x10x3 rectangular magnets. It ruined the print and caused a huge clog, but I came up with another way to embed magnets because of it.

      I designed a long 10x3 tunnel into the print, printed the object without pause, then slid the magnets into the tunnel. I printed a couple spacers to go between the magnets to place them how I wanted them and I printed a plug to glue into the opening of the tunnel. The plug was a second color so it stood out and made a little accent.

      I haven’t done it yet but I thought it would be cool to add a little decorative design to the original object to be printed in a second color and make the tunnel plug the same second color and hide it in the decorative design.