ma·chine (m
-sh
n
)n.1. a. A device consisting of fixed and moving parts that modifies mechanical energy and transmits it in a more useful form.b. A simple device, such as a lever, a pulley, or an inclined plane, that alters the magnitude or direction, or both, of an applied force; a simple machine.2. A system or device for doing work, as an automobile or a jackhammer, together with its power source and auxiliary equipment.
Exactly which one of these definitions of "machine" does the simple pendulum satisfy? I simply don't see the simple pendulum as a machine. I guess you could claim that a spinning disk is a machine also. A spinning disk is something that should continue forever unless acted upon by an outside force. Both the simple pendulum and the spinning disk is in equilibrium with itself. The MMF system converts an up and down motion to a rotational motion satisfying both definitions 1a and 1b. If loaded, as when riding a bicycle, it also satisfies definition 2.
Yes, it should be possible to work this entire problem out mathematically. The only issue would be the assumptions used for calculating the losses in the materials used. What would one use for the soft tissue of the leg for instance?) If there is an adequate system for analyzing this why doesn't some one do it and prove me wrong. All we have is hyperbole coming from the believers in the preposterous notion that this machine has no losses.
If you were an engineer or a pragmatist you'd recognize it as a machine. -shn)n.1. a. A device consisting of fixed and moving parts that modifies mechanical energy and transmits it in a more useful form.b. A simple device, such as a lever, a pulley, or an inclined plane, that alters the magnitude or direction, or both, of an applied force; a simple machine.2. A system or device for doing work, as an automobile or a jackhammer, together with its power source and auxiliary equipment. Exactly which one of these definitions of "machine" does the simple pendulum satisfy? I simply don't see the simple pendulum as a machine. I guess you could claim that a spinning disk is a machine also. A spinning disk is something that should continue forever unless acted upon by an outside force. Both the simple pendulum and the spinning disk is in equilibrium with itself. The MMF system converts an up and down motion to a rotational motion satisfying both definitions 1a and 1b. If loaded, as when riding a bicycle, it also satisfies definition 2.
Yes, it should be possible to work this entire problem out mathematically. The only issue would be the assumptions used for calculating the losses in the materials used. What would one use for the soft tissue of the leg for instance?) If there is an adequate system for analyzing this why doesn't some one do it and prove me wrong. All we have is hyperbole coming from the believers in the preposterous notion that this machine has no losses.
Regarding the "MMF", you do realize that if someone were to model this, the FIRST step would be to assume a rigid body system don't you? That's engineering 101 at work there. Same thing with a mass-spring system. You start with the "unrealistic" model of no losses which actually tells you a WHOLE lot. You can bump up the fidelity and add damping and such as you get smarter or more adventurous, neither of which I'd suggest in your case for obvious reasons :) But as you add those "losses" you better have some good data. For this particular problem you could merely parametrically investigate the effects of various system damping, friction losses, and such.
I understand that. A rigid model is useful for looking at forces and stresses on materials but not much else. As I said above, how is such a model useful for modeling real world energy losses if that is what you are interested in studying?
No, my "mistake", at least from your view, is not falling into line and accepting the prevaling view that an idealized model that ignores the possibility of internal losses is a good model to analyze internal losses in real life. I don't buy it. I am surprised that you are taking this side. What is your evidence that this is a good model for this purpose?
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Frank,
An original Ironman and the Inventor of PowerCranks