Interesting timing, this topic.

I'm actually working on acquiring an original Tron handle to do this very thing. I originally wanted a set for myself, but when I discovered how hard they were to find, I decided why not make them availiable to everyone- that way BYOAC'ers weren't hacking up original grips to put on cabs, and owners of original Tron cabinets could get replacement handles.
I don't know if Tom was injection molding his- injection mold tooling usually isn't cheap. A group of friends and I are pretty experienced in different molding materials and casting resins- I was going to give it a go. I was planning on offering the blue and red, as well as triggers. I don't know about ready to go, wired sticks.
I was trying to come up with an adapter so you could fit the grip to a standard Happ joystick, but I'm going to have to wait until I get the grip.
So I dunno. I have to find a grip first.
I thought about offering reproduction Star Wars yoke handles too, but a whole yoke is hard to find, let alone the grips. Anyone wanna loan out a set?
