# FIRST Team T-Shirt cannon advice

1. Aug 5, 2015

### CiscoCertified

Hi all, I had a question regarding an off-season tshirt cannon my team is doing. We have to choose between wheel launched (two wheels with loading system similar to pitching machine) or compressed air. I am all for compressed air because it has been done time and time again but from what I understand the wheel method is unorthodox method compared to compressed air. Below our the teams concerns that are against me on this issues.

• Cost
• Time
• Complexity
My disagreements are that building a tshirt launcher with unorthodox methods will cost us more in the long run because there is no viable proof that a specific setup will work and won't require major tweaking, so that knocks both time, complexity, and cost. We have a air compressor that will provide .88 cfm and a resevoir that will hold 36 cubic inches. We have relatively small tubing (a bit bigger than your average drinking straw) and we need to launch a tshirt from 50 meters at most a 45 degree angle. No one considered the math involved in this and I want to see if this is possible. Before I can argue my reasoning I would like to understand if this is possible with all of the variables taken into account. We would really like to fire multiple tshirts on one charge. In addition, how many cfm and psi will it take to launch a tshirt 50 meters, it can be ball park. Thanks! I just want us to use the best method.

UPDATE:
Here is another teams cannon and they are using the same compressor as us, and what looks to be similar diameter tubing. Of course we would use metal plumbing pipes (black ones from home depot or lowes). In addition to the questions above, how can we increase the amount of tshirts we can fire without getting a new compressor, (we can get a bigger secondary air chamber if need be)

Last edited: Aug 5, 2015
2. Aug 6, 2015

### DEvens

I notice that Safety is absent from your list of concerns. Mr. Subliminal wishes to mention that $_\text{Maud Flanders}$ compressed air is dangerous.

Have you considered a simple catapult? A t-shirt wrapped into a tight little ball and simple tossed by hand can easily go 20 meters. I could do that and I'm very nearly spherical. (That's a real picture of me in my avatar image.) A lever with an old inner-tube for a spring could probably launch a t-shirt well over 40 meters without much trouble. Wrap the t-shirts with a couple rubber bands to keep them in a tight package. You can even mount some kind of sound-creating thing at the top of the lever's swing. For example, it could ring a bell every time it launches the t-shirt.