I designed a part that has compartments for small neodymium magnets. The compartments open up on the side of the part, but ideally the entire part should look smooth and featureless, and the epoxy I use is not the same color as the PLA. Also, I’d like to be able to fish out the magnets later, and epoxy is a bit too final for my taste.

So I’m thinking of dropping a small dollop of melted PLA into the openings to seal them, then file / polish them smooth. It would be sticky enough to hold the magnets in place yet easy to pop off with something pointy or sharp if need be.

And to do that cleanly, I figured I’d get me one of those cheap freehand 3D pens as a kind of precision “glue gun” for PLA. And it occurs to me that I might also be able to use it to “weld” small parts together, and hand-write things on parts with a different color filament.

I’m not much of an artist so I have no use for a 3D pen as an artsy tool. But it seems like a useful thing to have alongside a 3D printer, and they’re not that expensive - even the more expensive Mynt3D 3D Pen Pro, which is the one I’m eyeing.

Does anybody know if those 3D pens can be used for small manual reworks / assembly of PLA parts?

  • @TheyHaveNoNameEnglish
    7•10 hours ago

    I do this right regularly. I created a huge trash can shape container using 8 separate pieces printed in PLA. I then glued together with CA glue and welded the pieces with a 3D pen to make the joints stronger.

    A couple of things to remember:

    3D pen don’t push the filament like a 3D printer does. You have to slow the flow of the pen down, and let the filament bind to the layers below

    There’s a big difference how different PLA will behave with a 3D pen. Some filaments won’t stick as well like others

    You have to mimic the behaviour of a printer with the pen. So you have to lay down layers of filament, rather than trying to make it behave like a glue gun.