# Flywheel trouble

1. Apr 13, 2007

### Yakatyak

Am having some trouble with a project at the moment and wondered if anyone could help.

Essentailly the project was to design an energy storage sytem to propel a small buggy. We opted for a flywheel, the buggy wheels and hence the flywheel are to be accelerated on a rolling road and then the buggy is to be released on the floor.

The problem I am having is try to work out the torque exerted by the flywheel through the wheels onto the ground, and then hence work out a formula that can tell me whether the buggy will "wheelie" , wheelspin or propell itself forward.

Any help would be much apreciated

2. Apr 14, 2007

If you are talking about a small toy buggy car, make sure the wheels are rubber.this is sure to increase the friction, so you cant prevent wheelslip. An alternate would be to make your buggy heavier, but that wouldn't propel it very far...

3. Apr 14, 2007

### CPP

If you want to take this that seriously you are going to need to lay out a design that you can draw dimensions from and then work gear ratios. To make this a conceptual head problem would cause me problems for sure.

4. Apr 15, 2007

### Yakatyak

I understand most of the concepts and idears and can deduce a lot of things that are required. However given a certain set of constants, friction (muR) , flywheel angular velocity , buggy mass etc etc, I can not work out the torque that the flywheel exerts on the driving wheels of the buggy. I understand that the torque must be less than the wheel radius * friction, for it to not wheelspin, but i just can not seem to work out the torque applied by the flywheel.

It appears to me so far that the flywheel only exerts a torque when it is loaded and so should exert a torque equal and opposite to the friction applied to the driving wheels, is this correct, i'm not sure.

5. Apr 16, 2007

### brewnog

Do you have a formula for inertia?

6. Apr 16, 2007

### Yakatyak

yeah, 1/2 MR^2 , as it is a solid cylinder, we chose this as it would be far simpler to balance than a flywheel with more mass distributed around the outer part of the wheel.

7. Apr 16, 2007

### Aero Stud

A flywheel for a buggy ? Doubt anybody tried that before. You need it to be heavy to store anough energy, you need it to spin while the buggy is moving, you need changing gears for different rpm... To me at least that all sounds quite complex. Unless of course it's leterally just a small buggy that has to go streight just for a bit and stop and that's it so it's simpler than that and you don't really need different gears.

May I perhaps suggest the idea of a torsion spring, like those toys where you turn a key and it runs. If you make the buggy load the spring itself it's still a serious project anyway, and also more likely to work or work better I think.

Last edited: Apr 16, 2007