Any prototyping options for rubber overmolding?

[rf-fil]

I would like to avoid major tooling cost for rubber overmolding for a small part. It's for a custom electrical cable, so the overmold will be about half an inch in diameter and a few inches long. The wire is raw (no sheath) so it's rubber over metal. I'm an electrical engineer and I've never designed a part like that. I understand tooling cost might be in the thousands so I want to check my design before I commit to tooling.

[thm_w]

You can 3D print a mold and pour that: https://markforged.com/resources/blog/casting-3d-printed-parts
Might also be worth directly printing the part in PLA and TPU to see how it fits.

Probably worth asking the supplier you intend on using as well, unless you are overmolding it in house?

[Infraviolet]

Is this a part which needs to be rubebr for its flexibility, or is this a part where rubebr is just being used for insulation properties? Part of me wonders if, in the latter case, a rigid part would be good enough for prototyping?