I recommend printing from FLEX with hardness 98A. It has worked well for me to vary the number of perimeters at different heights (see my G-code).
After you have printed the T-STICK, you need to put the melting nuts M5 into the holes on the top of the T-STICK (I bought these).
Finally, you can use the long screws (or threaded rod) M5 to attach the T-STICK to the steel you are attaching to the powerchair.
The author remixed this model.
Adjusted for printing in one piece. Required print area 300+