Evan,
I am suspicious that a rotary broach will not be a fruitful approach to
this problem -- While the idea intrigues me, you'd basically have to
build one of your own from scratch, and the ability to do that almost
defeats the purpose unless you're hoping to mass produce.
The problem is that it appears that servo splines such as those used by
Hitec are proprietary, and COTS tools do not exist to replicate them.
That stated, I did find some bloggers who talked about their success
building custom splines that could mate with certain servos:
https://hackaday.com/2015/02/01/spline-thieving-makes-hobby-servos-even-more-useful/
I'm afraid they didn't specify what servos they mated with, but if you
have the tools available, you can replicate their approach.
Typically, though, unless your part is meant to be very small, or must
be made out of a special material, one would simply find a way to mate a
standard servo horn to the part in question. These, for instance, are
threaded:
https://www.robotshop.com/en/hitec-spline-metal-servo-tapped.html
https://www.hobbytown.com/aluminum-pro-adjustable-double-arm-hitec-servo-horn-blue-by-racers-edge-rce10385b/p37169
Would you care to share your results / whatever solution you end up
landing on? I'd be quite interested to see what you are up to.
If anyone else here knows a back-alley way of getting the same tools
that Hitec uses for their products, I'd love to hear about it too.
Otherwise, Evan, I think the above may be your only options.
-- Georges Oates Larsen
Portland State Aerospace Society
On 08/30/18 11:05 AM, Evan Daniel wrote:
Does anyone know where to get rotary broach tooling for RC servo shaft
splines? Specifically looking at the Hitec spline pattern, but would
be interested in hearing about others.
Some Google work has only yielded a few forum threads with the same
question and no answers.
Evan Daniel