Everybody, I just talked to Atkins rotary. They will provide as an
assembly a single rotor/eccentric/flywheel/balance weights. Assembly
is balanced to within a gram and guaranteed to run smoothly. The
eccentric is cast. They make the complete single rotor engine for
marine application. While I don't like the idea of a cast
eccentric, on the other hand it is very short and therefore very
stiff. The price is $1500.00.
What do you all think? Also they quoted $150.00 for a set of
tension bolts. Jerry
Jerry,
I spoke to the metallurgists who tested the Rotary shaft for me
( they are
aviation accredited) I suggested to them that I was considering
casting some
and they suggested to me in no uncertain terms that because of
porosity
problems, they could in no way recommend a cast crank for Aviation
use. I
will leave it to you to make the final decision.
I have found a local chap to turn my single out of 4140, he's a
neighbour
and is doing it as a favor so will cost me a couple hundred bucks.
That's
not including the cost of material grinding, heat treatment and final
runout checking and adjustment with final polishing. However I have
asked
him to work out a cost (given the first is an assessment of time
and method)
so that he can quote on providing the same thing to others.
I did ask Larry to consider this on two occasions, but as yet he
hasn't
responded.
George (down under)
A one rotor e-shaft is not highly stressed. The same output e-shaft
diameter supports
the torque from a four rotor engine. Cast iron, if done properly,
will work
fine for a one rotor. Wankel Gmbh Germany patented a hollow e-shaft
hydro formed from thick wall steel tubing.
Paul Lamar
Do you feel, then, that the cast eccentric is probably reliable?
Jerry
I would say so if it is cast properly with the right iron alloy and then
heat treated and polished on the wear surfaces. The devil is in the details.
Paul Lamar ...No rotor no motor.
Paul,
The aftermarket cast iron chevy V8 cranks hold up to a lot of abuse and seem
to stay together much better than the factory cast cranks.
As long as the single shaft is made out of good nodular iron and heat
treated correctly, it should not be an issue, but a good ground test program
with a tear down for magnefluxing the shaft would add insurance. Atkins may
have this data already. Worth asking.
Larry
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