My take on a drop-in t-nut for 3030 aluminum extrusions. Model has snap-off printed supports so it's a guaranteed good print each time.
I had really good results with .4mm nozzle, 15% in-fill .2mm layer height.
Will work best with M3 nyloc nut, but should work fine with a standard M3 nut as well.
The built-in snap-off supports have a designed .2mm spacing all around, I found they were pretty easy to snap off with small pair of pliers.
If you use the nyloc nut it provides plenty of friction against the bolt to turn the t-nut vertical in the slot every time.
The author marked this model as their own original creation.