About vibrations. After first seeing an animation of how a WWI-era rotary engine worked several years ago it struck me that they should be relatively vibration-free compared to other, more traditional reciprocating engines. All the moving parts (and therefore their masses) are are prescribing perfect circles, meaning that if they're properly balanced the whole thing should
run as smoothly as a bicycle tire, except possibly for a small vibration associated with the actual combustion. As this video shows, a radial, or inline for that matter, engine has the mass of the pistons and piston rods changing directions hundreds of times per minute. That's gotta add something.
And finally putting this idea in writing has just popped another into my head. The effects of gyrosopic precession on rotaries is a favorite topic of WWI simmers. I'm no engineer, but I would guess that GP could be predicted based on the mass, speed and axis of the gyro. But these engines actually had two
masses of different sizes and with different axes and probably different masses creating gyroscopic forces: one for the cylinders and the other for the pistons and piston rods. I wonder what effect that might have had on GP?
Any mechanical engineers out there care to weigh in on the subject?