[GreenKeys] More 28 reperf hammer head

[Nick England]

Good thinking, Bruce - Tire rubber seems about the right combination of
flexibility and hardness.
I also got a 0.25" thick buna-n/vinyl (nitrile/vinyl) sheet from
McMaster-Carr to experiment with - it also seems like a reasonable
candidate.
BUT - how to cut that slot is the big question. I'm going to try an X-acto
knife chisel blade to see if that can cut straight enough. I just don't
know.
So far there are several greenkeyers working on a 3D printer solution -
maybe that'll work. My experiment with a crudely molded hammer is
encouraging enough that I'll pursue that if printing doesn't hold up.

FWIW, I've also gotten a quote on NOS parts from one of those "obsolete
military parts" vendors - they want $10 ea. for quantity 50. That's way too
big a gamble to get what might be crumbly plastic - or might be good hammer
heads - no way to tell as they won't supply a sample.

Nick England K4NYW
www.navy-radio.com


On Wed, Jan 15, 2020 at 7:34 PM Bruce Gentry via GreenKeys <
greenkeys at mailman.qth.net> wrote:
>
> I have an idea for getting the hammer made. Does anyone know if laser
cutting is available for rubber? The thought is to get a chunk of tread
rubber from a discardedï tire, and get the rectangular slot cut into it
with a laser. That is difficult part, the rest of the shaping can be done
with a grinder and/or razor blade. The other possibility would be to get a
small piece of uncured tread rubber from a retreading shop, shape it around
a correctly sized piece of metal to form the slot, enclose it in a small
sheet metal mold, and then bake it to complete the vulcanization. It could
then be worked to shape and size with a razor blade or grinder. I think
tire tread rubber would stand up to the job quite well.
>
> Bruce Gentry, KA2IVY
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