Drop-in M4 and M5 T-slot Nuts for 80/20 Aluminum Extrusion

thingiverse

This is a post-assembly drop-in style T-slot nut designed for use with 80/20 aluminum extrusions featuring an 11mm width at the top of the T-slot, a 6mm wide opening, and approximately 4mm deep in the bottom of the T portion. The 1.8mm slit within the 6mm wide profile is also accounted for in this design. The OpenSCAD model was created to accommodate various T-slot profiles, allowing users to easily adjust the dimensions as needed. This drop-in T-slot nut is specifically designed to be inserted into the middle of an extruded rod and rotated into place, ultimately catching in a perpendicular orientation. Both M5 and M4 STL files are included for users to download. The M5 version operates at the tolerance limits of what will print well within the 6mm profile, while the upper cylindrical thread extension is thinner than the bottom portion due to design constraints. When tightening bolts into the M5 version, it's essential to note that a snug grip won't be achieved if only the upper cylindrical threaded portion is used. However, tightening through the entire length of the nut will result in a secure hold. In contrast, the M4 version boasts a stronger grip due to its thicker plastic wrapping around the bolt. Although these drop-in T-slot nuts are not as robust as metal nuts, they can still be effective for assembly purposes. During tests of strength limits, I successfully suspended my 10kg printer (I know, it's heavy) in mid-air using a single one of these nuts, provided it was screwed in all the way. While this may not guarantee similar results for other prints, I believe these drop-in T-slot nuts can be useful for assembly. However, users must exercise caution to avoid overtightening, as this can lead to stripped threads due to the combined leverage advantage of an Allen wrench and threading forces.