T8 Leadscrew to Stepper Coupling, designs for 8mm and 2mm lead, fits Nema 23's. Lead Screw Coupling

thingiverse

Designed these connectors to link T8 lead screws with both 8mm and 2mm leads directly to NEMA 23 stepper motors. I've also developed designs for collars and clamps, which you can find among my other creations. The connectors are threaded to fit securely onto the end of the lead screw, then clamp in place. A plastic component flexes to hold the shaft firmly, requiring two M3 nuts and bolts - 15mm long was the length I chose. Yes, there are slight differences between the two designs; one has recesses for the M3 nuts, while the other doesn't. No particular reason; I simply didn't get around to updating it. Printing these connectors will largely depend on the tolerances of your machine. If you find them too tight or loose, try scaling accordingly. Remember that even small variations can lead to significant results - but ideally, they should be as snug as possible while still allowing for easy assembly. I designed them to be printed with the threaded end facing down against the bed. I used ABS for my prints. You'll need to use support material for the arm sections and possibly a substantial brim or similar feature to provide sufficient contact area for the print to adhere well to the bed.