What size should I build the wheel?

[Leafy]

I just found the math for gravity wheel.
I'm thinking what size should I build the wheel.
The math shows that if you double the diameter, the power is quadrupble.
So i'm thinking the larger the better.
Maybe 6 ft because I want to move it in and out of the house if needed.
Should I sim it first? I'm almost certain the sim will be a runner but that means give the wheel away to simmer.
Should I hire a builder? That also means give the wheel away to builder.
I'm not sure I want to build it myself, too laborous since I'm a math guy.
Man...what to do.

[Tarsier79]

Learn to build, or learn to sim.

Build size depends on budget, materials, build competency, build complexity, availability of room, availability of time, ability to adapt on the fly.

My current build is over 6 ft high on the stand. Most of it is cut on my cnc router, which has a table 30 x 18cm, so mine is designed in bitesized bits bolted together to make a whole.

Good luck.

[thx4]

I'm not sure I want to build it myself, too laborous since I'm a math guy.
Man...what to do.

If you are a mathematician, so the simulation has little interest and especially if you are 95% sure that things should take a favorable turn :)
If you are willing to work with a member of the forum, I'm a candidate. I have enough material to make a working prototype from your plans, but a simple sketch should be enough...
We can work in public or in private as you want.

A++

[Leafy]

You know what, this is the 21st century, who cares about money. I’ll post up the math for fun.

Consider a wheel of large moment of inertia and radius. A mass is first allowed to descend with the wheel for a short distance as shown. It is then compared to the second case where it is free fall dropped for the same distance. The energy is the same for both cases.

Moment of inertia I = 10,000
Radius of the wheel r = 1000
Mass m = 2
Drop height h = 3

First case, descends with the wheel:
mgh = .5(I)(w^2) ———- GPE converted to wheel energy
w = .1095. ———- rotation result is .1095

Second case, allow to free fall and impulse:
mgh = .5(m)(v^2). ———- GPE converted to kinetic energy
v = 7.746 ———- result in speed of 7.746
Ft = mv ———— impulse when hit the wheel
Ftr = I(w) ———— impulse converted to angular momentum
w = 1.5491. ———— rotation result is 1.5491

As you can see, two different methods yield different rotation. The impulse give more energy than the lever.

[Sam Peppiatt]

leafy,
Seams like they should come out to be more or less the same. But, I'm not a math guy----------------------------------Sam

[Leafy]

Thanks Sam,

I'm afraid you're right. The math is error. I just saved myself big time from going further. Ah... this sucks.