poza

I should add that the width was determined by the metal pipes I used as axles. I didn't want to cut the pipes (I'm lazy), so I cut the wood that makes the width of the base to match the pipes. I suspect it will be more likely to have a few Bic ink pens laying around that can be used for axles, so use them to determine the width.

I used wood I had laying around. It's height is half it's length. So a 12 inch length would result in a 6 inch height and width.

This design could easily catapult an egg. The only modification might be to add a second rubber band to handle the extra weight of the egg.

Concrete pipes ~may~ be cheap (i dunno really), but transporting and setting them in place isn't. This is a very creative and impressive build, but not suitable for the homeless.

I'm glad I'm not the only one who thought this was rather insensitive. I'm sure the author/maker had no ill intentions, and I certainly don't want to turn this into a political discussion, but this is poorly suited for the homeless. And for that matter, the author/maker probably had no intention of it being used by homeless. The professor in charge of this project, on the other hand is probably the insensitive one.

The author used a US quarter. The US does not use a gold standard. That is, there is no supply of gold in ft Knox or anywhere else that your US money can be traded for. The US uses a "Fiat money" system.

It would be wise to use safety glasses.

Good point!