Kenneth
     Did a little more study of splines and find
that 24
     pitch is standard. That dictates a shaft
diameter of
     1.125 with 27 teeth or 1.25 with 30 teeth. Do
you
     think it feasible to shape internal splines in
lobes
     using EDM to minimize distortion and stress?
Also did
     a quick calc of torsion and find a 1" shaft
with
     active length of 8" will windup about 1 deg
under
     500#' torque. Don't know what's acceptable or
if I
     analyzed correctly. What do you think.
     regards, Robert

Robert,
You are correct, I don't believe you would ever have
success broaching a
spline. I personally think persuing this method
would be folly. By the
time you have made the structure tight enough to be
workable it would be
cheaper to turn and grind a shaft using a
conventional method! The fact
is that the e-shaft is a rather simple setup. It
requires that someone
with the proper dimensions go to someone with a
crank lathe and grinder
and pony up to get one made. FWIW
Bill Jepson

Rolf and Bill
Thanks for the comments. Glad to get expert opinions
on this. I guess if this were a viable approach it
would already have been done.
regards, Robert

Robert



To make a broach to press through the e-shaft lobe and bearing adapters When
you ger your spline made the desired length get them to make a twelve inch
long tapered spline that is .002' larger at one end and taper the outside to
the size of the valley between the teeth at the other end You want a 1/4"
hole through the center. Cut it into one inch numbered sections then have it
hard cased.

You then assemble the twelve pieses in the reverse order and put a 1/4"rod
or bolt through them. You will not have difficulty pressing this through the
drilled out lobe or bearing adapters.

I just suceeded in pressing a 3.3" 90 tooth broach through a 3/4"section of
a hole machined in two 12A rotors.

The shaft in the following directions Is fully enclosed within adapters or
lobes. there is very little deflection.

It requires intermediate bearings.

Instructions for making a balanced e-shaft

For general information the spline in the clutch disk in the 12A rotary
engine is less than a .9" inside diameter.

A Mazda e-shaft lobe has approximately a 2.92" diameter. I guess it has
about .01" hard casing around it

With driveshaft quality steel with a ¼" center oil hole  make a 1.182"
diameter spline with eighteen teeth the desired length of your engine.

Make a broach the same as the aforesaid spline and have it case hardened.

Drill out the oil hole in the e-shaft lobe sufficiently to enable pressing
the broach through creating interior teeth in the lobe.

Also drill holes in bearing size steel (adapters) and press the broach
through to place them as desired on the spline in your engine configuration.

Weld whatever end type you desire to the adapters.

It is suggested that bearing support be provided at intermediate housings.

In a two and four rotor configuration the lobes would be placed at 0 and 180
degrees.

In a three rotor configuration the lobes would be placed 120 degrees apart..
Kenneth McKenzie

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