cobra marty,
That's Awesome! Great idea.

Good ole phi = TL/JG put to good use.;)

phi = TL/JG ?

phi=Torsional deflection(degrees)
T=Torque(in-#)
L=Length(in)
J=Polar Moment of Inertia(in^4)
G=Modulus of Rigidity(#/in^2)

You're measuring deflection of the shaft, right? Solve the equation to gain internal torque(T). Once torque is known and rpm is measured, you can solve for horsepower.

Is that how the device works? :)

Sort of. I can skip all that because with a known TQ applied = proportional measurable change in deflection. This way I don't care about J, G, or L.

Very cool...Love the idea. :cool:
Just curious, where did you obtain the torque vs deflection data for that particular shaft? Was it through measured testing? How will this apply to other such application(other drive systems)?
Just curious. :cool: