Average rubber bands on a puncher

So it’s my first time building a puncher, and I feel like I’m adding way to many rubber bands. How many rubber bands do you guys normally put on yours? I know every puncher is different, I’m just trying to get a ballpark number.

I personally use two rubber bands, each doubled up on either side. For my puncher it’s worked really well, it shoots much faster and harder than I need it to. Just make sure that both rubber bands are equally tensioned and don’t leave them tensioned when not being used

How far did it launch? I tried mine with 6 and it shoots about 6 feet.

A big question is how far you’re drawing it back. The energy stored goes as the distance stretched squared. So, for example, if you use 6 rubber bands instead of the 4 that someone else uses in the same fashion while only pulling half as far back, you’ll only have 3/8 of the energy in the puncher. As a quick estimate (because there are height issues), we can just look at horizontal range, which goes as v^2 or as the energy. So in this example the ball would likely only go roughly 3/8 as far.

Another deceptive issue is what happens to the spring constant when you loop up rubber bands. If you cut a rubber band and check its spring constant and then compare it to what you get from the normal loop, you’ll find the loop has roughly 4x the spring constant of the straight piece, double for being half the length and double for pulling along two sections. So depending on what someone is describing when they’ve “doubled up” rubber bands, they may be multiplying the spring constant significantly.

So you might want to be specific about how you’re using your rubber bands and be sure what others are saying. Photos can help.

wow you really know your stuff

I used for my puncher which can be seen here for reference

used 4 size 64 rubber bands per side, so 8 in total.

@ReeseSteindler Sorry for the late response, the puncher shoots both the high and low flags from a distance of 3-4 feet away from them.