Straight to the point! I <strike> want </strike> will build a BIG slingshot that will use aluminium beer cans (or soda cans) as projectiles. I tried searching if someone might have done something like this before, but it turned out to be quite hard, since people seem to be using beer cans mostly as targets for slingshots, not as ammunition. This idea comes from when I was innocent teenager and made a spud gun (picture no. 2 for reference) with my friend that was able to shoot projectiles like soda cans and oranges up to 200m (that was an orange, no distance data from cans ). Now I really want to replicate the results with mechanical energy. I sratched out the idea for the frame (picture no. 1). I want to use the standard plumbing pipe as a barrel as it is really ideal size, 70mm inner diameter and the 33cl cans have 66mm outer diameter. I might consider rectangular barrel, but I have some crazy ideas for the beer cans that will only work with circular barrel. But I wont reveal those ideas for now Enough to say I want to use the pipe. I have some concerns about launching the projectile. Should I use a sled? I demonstrated this problem in the lower section of the first picture. By just using rope, would probably lead to problems. What do I need to take into consideration when I design a sled for this contraption? I think weight of it at least needs to be added into the weight of the projectile when thinking about power. And now perhaps the question that I should have asked first I ordered 5m of theraband gold. That ought to be plenty more than I need right? (Picture 3 I input the data to the calculator and I got the following: 40cm long strips, 3 per side, total width 18cm (per side). this means 6 pieces of 6x40cm strips of TBG in total. So per side that makes 3 pieces of 6cm wide, 40cm long strips. But what do you think, I dont have experience with this big slingshots? For those still bothering to read, here is some background: I am now a 3rd year mechanical engineer student and I´v always been interested in building stuff like spud guns and crossbows etc. But I´v never really been into slingshots, since I´v only ever bought some shtty ones. The rubber was so hard to find that I just stuck with materials I got easily like old skis for crossbows. But now I´v been watching practically nothing else on youtube for the past week other than slingshot channel. And boy am I hooked! I just bought 5m of TBG from ebay and I´v gone to the hardware store to look through some materials for this big ass project and also for making a smaller one to begin with. Also got myself a few extra tools that I will need, like a hole puncher and a rolling cutter. Now I´m just gonna be a anxiously waiting for the mailman for the next week or so PS: What would you even call this (not the name, but the type of slingshot it is?): Ballista? crossbow? slingshot? slingbow ballista?