This is what I learned while using magnets seriously for the 1st time in a project…
One standard magnet size is 10×3mm, a snug hole is 10.3×3.1mm – of course this also depends on your printer’s calibration, and that the magnets are true to size.
Do a fitting test with your holes, in a draft print.
If you have 3 or more magnets, do not place all of them at the same height.
Make pairs of fitting magnets, mark them on the (future) inside faces (i.e. when stuck together, the outside ones). Do not use Edding, that weakens any glue adhesion (scratch them instead).
Use superglue sparingly, so it does not overflow or only a little – apply a tiny drop to the hole’s middle.
Apply with the magnet stuck to e.g. the nose of flat pliers, insert perpendicular and apply pressure with just a corner of the tool to the center of the magnet – that avoids any “tool stuck to the magnet or your object” situation.
Work pair by pair, so they really fit in the final assembly.
Take care that the scratched face goes INTO the hole.
Wipe glue overflow by turning a folded paper towel on the spot, no smearing glue around.
When I use magnets, I embed them into the model, no glue required, magnets are invisible and when attached to a metal part, it does not scratch the surface. For your example of 10x 3mm magnets make the hole 3.6 deep, pause printer when it reaches 3.2, insert the magnets and resume printing.
I guess I will try that out if there’s a need (you mentioned a few reasons), but I prefer to not needing the timed manual intervention for now. Maybe with a box / lid design where all the magnets go in at once, near the end.
When I’m modelling in fusion, just use an octagon (circumscribed polygon edited) at the magnet size. For Studio if I want to add a magnet, I’ve made up a set of octagonal-cylinders (eg. 10x3magnet.stl) and simply import via “add negative part > Load” and place where i want the magnet.
I have a lot of embedded magnets in a few existing models uploaded and in a series of new models all using magnets.
I use the PAUSE feature which gives you time to insert the magnet into the printed model and then print over it so it is embedded.
I add 0.4mm to the radius of cylinder magnets and no extra to the height. I learned adding a tolerance to the height even by 0.2mm allows the magnet room to move in the model and a gentle shake makes noise.
If you use small magnets, you should use an insertion tool, there are many here.
If you place a few magnets at a time, stack them up in the same direction you need them (north vs south) and plop them into the hole, slide to the next hole, plop and repeat. Even with minimal infill, this is easy to do and the slide and plop method means you will not accidentally flip the magnet pole direction and it greatly eases the process and speed of insertion.
I do a lot with 3x2, 6x2, 8x2, 10x2, 10x3, 15x3, 20x2 & 25x2mm.
It depends on the product, the model, the placement and most importantly, the distance from the matching magnet as the strength to close and open can affect the end model.
I have models that use press-fit that rarely need glue, but, those are usually smaller magnets 3x2mm ones, with only a drop of glue if the filament strength isn’t great. Magnets which are that small should not have a tolerance around them.
I have a questions. I’m trying to embed magnet in a project as well but the project has overhang and required support. When I enable support the slicer puts supports inside the cavity designed for the magnet. Since the cavity is invisible I can not remove the support through the right mouse support painting (removing). So how do I tell the system to leave the magnet cavities alone and empty?
There are always support blockers in studio. You can also set the supports to on build plate only.
Also check your support settings. Or set them back to default. I never have it generate supports, so i though this was a odd issue. Although I only go up to 8mm magnets.
