Welcome to the SeeMeCNC Community

I thought this was interesting, just order a few to try when constructing my enclosure.

https://www.matterhackers.com/articles/ ... d-printing

Been using them for several years and they are excellent. I made a tip for my soldering iron but some small normal tips will work. The tips they sell for the purpose are not absolutely required.

I use them also. They are great.
Use small tip on soldering iron, just enough heat to melt plastic, any extra heat does not work as nice.

You could mount a heat block to a nice shaft, clamp it in a drill chuck of a drill press and then you know the inserts will always be perfectly vertical. And you have better temp control than with a soldering iron