T-nuts for 5mm (and 6mm) 2020 Extrusion Slots

thingiverse

I have a Taz 4/5 and a Taz 6. I made a top mounted spool holded for my Taz 6 and found the the slots in the 2020 extrusions were 5mm instead of the 6mm wide on the older model. I have metal T-nuts I bought on Amazon, but they are 6mm wide. I tried grinding them down. Did not work too well. So I designed some 5 mm wide t-nuts for M3 screws which worked OK. I made some out of PLA, PETg, and ABS. I used an M3 tap on most but you can get away with just using a screw to cut the threads. I have also included some 6mm wide designs for M3 and M4 screws. I definitely recommend using a tap on the M4 ones to prevent splitting. Use a fine layer height. I used .15mm with a .5 nozzle on Taz and .4 nozzle on my new Prusa I3 MK3. I would always go for metal t-nuts if you have them. Using inserts in something this small does not work great. If you don't over crank the screws, the plastic ones work okay. Use washers. Make sure the screws do not bottom out in the extrusion. I have not seen any metal insert t-nuts for the 5mm wide slots except for the flat ones requiring end plates or corners to be removed. I hope someone uses this design and makes some metal ones!