>
> Paul
>
> I just talked to Doug Mueller about the shertz beam he says that he
> looked at Bill Schertz? (the guy who came up with the idea) install
> at his hanger and he utilized  two holes where the the bell housing
> would normally attach. is this a normal install for the schertz
> beam or is this something he added later?
>
> Tony

He is talking about the original mounting where the beam was
sandwiched between Tracy's plate and the engine.

-- 
Blake C. Lewis


I don't think so. Bill never did one like that as far as I know.
-- 
Paul Lamar ...No rotor no motor.

Well doug swears he saw that type of set up. But I was under
the impresion all this time that the s-beam only used the pan bolts.
So I was trying to sort out what he saw in Bill's hanger.
Are the pan bolts enough to hold the engine in say a 3 or 4 g turn?
if so that's good enough for me.

Tony

What Doug saw was Mark's engine with the beam between
the back rotor housings and Tracy's adapter plate.
We had a flex plate bolt clearance problem so we moved away
from that scheme. It was a design over site on my part.
Jerry fixed it by cutting slots and beefing up the top
of the beam with 1/4 square steel bars. Only one airplane
was built with that design I think.

3 or 4 G turn is no problem.
A pan bolt is 6 mm that is .236 inches in diameter.
 Six 6 mm bolts (.236" dia.) will
take 16,000 pounds in tension at a stress level of 60,000 psi.
Those are cheap bolts. Grade 8 bolts are over 100,000 psi.

The problem is when doing aerobatics with a 50 pound prop
you might see as much as 600 ft pound of twist about a vertical
axis while pitching or yawing at the rate of 60 degrees per second.
Something you might see in a spin. At 600 foot pounds of
torque the outer pan bolts could see a shear load of about
600 pounds. The bolt is good for about 1300 pounds or so in shear
so there is a safety margin of over 2. A wood or carbon fiber prop
would be half this weight so the loads would also be roughly half.
If you are worried about it add the clips as Bill did.