T-Nut 2020 M3 M4 for V-Slot - Printed Thread Rotating Nut

thingiverse

I wanted a T-Nut for 2020 rail with printed thread, but all I could find were designs with slots for metal hex nuts, so I created this. Actually, I disagree with using hex nuts in many applications - I've made a lot of components with slots like this, and I'm aware of the potential problems they can cause! Especially for parts this small, the plastic around the nut can easily tear, and then the nut will just rotate when you try to undo it. Not fun removing the screw when that happens. Of course, this is worst for lock nuts, but still, a printed plastic thread is strong enough for many applications like the one I need them for. Also, plastic has its own lock built in - just use a tap to clean up the start of the thread, not all of it, and the screw will not come loose under vibrations etc. So unless you need seriously high torque on the screw, this is much easier and in some ways actually better. An alternative to using a tap is to clamp the nut in a vice or whatever and force a screw into the hole with an electric driver. Then wait a bit for it to cool. The heat from friction causes the plastic to melt a little and can give you a nice thread, but it might force some expansion and throw off some of the dimensions. Still, it is an option to try if you are stuck. This is not something I have tried myself on this design but have done this with plenty of other designs in the past. These are designed for my printer, with fairly tight tolerances (0.15mm from walls either side). They printed fine with my 0.6mm nozzle. If you need a design that is a bit looser, just let me know - easy to add. Also bear in mind that first layer squish / elephants foot might need to be cut/filed off, easy enough to do, or just use the first layer horizontal expansion setting in cura. I have used the M3 and they work fine, I've added M4 which I have not tried but perhaps will be useful for someone.