Tee nuts legality

[vexatious]

Are tee nuts (T-nuts) legal?

R20 says:

Certain non-VEX fasteners are allowed. Robots may use the following commercially available hardware:
a. #4, #6, #8, M3, M3.5, or M4 screws up to 2.5” (63.5mm) long.
b. Shoulder screws cannot have a shoulder length over 0.20” or a diameter over 0.176”.
c. Any commercially available nut, washer, standoff, and/or non-threaded spacer up to 2.5” (63.5mm) long which fits these screws.

So, if tee nuts are nuts (which I’d argue they are), then yes.

I searched the Q&A and the only hit I found was:
https://www.robotevents.com/VRC/2023-2024/QA/1563
asking about R15 (not R20). The question reads (emphasis mine):

Last bullet (f) adds liquid nut tighteners. This should also include other types of lock nuts. Add: Jam, Nylon Lock, KEPS/K-lock, Flange and Serrated nuts are all permitted; T-nuts are excluded. (What about Wing?)

The answer addresses only the wing-nut part of the question, and simply cites R20. So I don’t see any prohibition on tee-nuts. But I could be wrong.

(I thought about posting the question to the Q&A, but the Q&A says it’s read-only.)

Thanks for any info!

[8goCrayzee]

i would think so, but idk why you would need to use them on a metal frame robot

[vexatious]

The linear motion trucks are made of softish plastic, and are supposed to be self-tapped with 8-32 screws. I want to use tee-nuts, with a slight counterbore if necessary, for a more durable joint.

Cf the first-generation (green) rack gears, which had brass threaded inserts.

(It would also be nice if the trucks were sold separately from the kit, but that’s a different issue.)