How to approach this snap fit to hold router bit

[user_1229734869]

see green dots in image - suggestions to modify model would be greatly appreciated

[EnoTheThracian]

I would do two arms in CAD with a round, empty space 0.2mm larger in diameter than the drill diameter. I’d stop the arms where their opening is 0.2mm smaller than the drill diameter. Add fillets for a cleaner look and better durability.

Or go fancy and embed a magnet. There are some really helpful posts by Bambu in the Community contributions for that route. Just one example:

Ways to Optimise a Magnet Socket

[1] Have you ever used round magnets and circular magnet sockets in your 3D prints? This practice seems simple. But you might still encounter some difficulties during installation. Why do we experience these issues? One of the reasons is that magnets vary in size. Additionally, minor design deviations and the printer’s accuracy limits affect how well the magnet fits the socket. Besides the factors mentioned above, material shrinkage during printing also affects the print results. You may hav…

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[CarbonForge]

@EnoTheThracian

Or go fancy and embed a magnet

Most good router bits are pure tungsten carbide these days, WC is only weakly magnetic.

[CarbonForge]

I’ll call a spade a spade OP - that print quality is so bad you can forget trying for any precision snap fits that will work consistently.

You’re looking for a feature that physically interferes but can also comply just enough to let the bit get pushed in and out easily - that’s an exceptionally small window you’re trying to hit, whatever’s going on here is going to make that difficult to impossible with any sort of consistency.

[RocketSled]

The plastic the bit is being snapped in to has to have some elasticity to it. As designed, there is zero flex except for whatever the plastic has in compression, which is going to be very minimal. So if you try to force the bit in to the slot, the plastic that’s interfering has no where to “move” so the bit can sneak past.

Cut a “moat” around the pocket where the bit will go, so that the walls of the pocket can deflect outward so the bit can get past the edge.

So it looks something like this:

[Eponymous]

For that I would do a U-shape like Rocketsled showed, but just a shorter one in the center.

Maybe not the exact form factor you wanted to fit into that box, but these are super durable and never let go accidentally. Part is from multiboard.

[Feuerbowle]

I would solve it with one or two small TPU insert that I would then glue into a pocket in the holder.

Something like this:

[user_1229734869]

Thank you all for great ideas on how to approach this project