Originally Posted by Hitchhiker 42 (Post 1620535)

What material did you use for the actual barrels where the T-shirt was nested? What pressure do you use to shoot the shirts?

Originally Posted by artdutra04 (Post 837509)

Rule #1 when making air cannons is do not use PVC.

Rule #2 is DO NOT USE PVC.

There are huge safety concerns with PVC, because PVC IS NOT DESIGNED TO HOLD ANY KIND OF COMPRESSED GAS, AND HAS BEEN BANNED BY OSHA FOR USE WITH PRESSURIZED GAS IN INDUSTRY. PVC has the awful tendency to spontaneously explode when pressurized with any kind of gas, even if that pressure is below the maximum pressure stamped on the pipe. (The max pressure rating for PVC is ONLY for liquids, such as water).

On a personal note, one of my friends had a PVC air cannon explode while holding it a few weeks ago. He wasn't even moving, and the air cannon didn't hit anything. He was just standing there, holding the pressurized air cannon, when it spontaneously exploded between his arm and his body. He was very lucky in that the way the shrapnel flew out, nearly all of it missed him. His jacket on that side of his body was not so lucky, and literally was torn to shreds.

Since this air cannon is being shown as for "marketing", it seems like it would most likely be used at public appearances. In order to protect any innocent bystanders from possible exploding PVC shrapnel, I would seriously urge your team to avoid using PVC on the air cannon at all costs.

I don't want to sound negative here, but at the same time I don't want to see people put themselves in dangerous situations.

Originally Posted by Roboshant (Post 1620556)

+ Concerns about the use of PVC

Originally Posted by Roboshant (Post 1620555)

What are you planning to use to rotate the barrel?Also how much space is there between the actual shooter and the barrel?

Originally Posted by Roboshant (Post 1620556)

+ Concerns about the use of PVC

Originally Posted by waffle_dynasty (Post 1620582)

The PVC barrels do not store any pressure. They are simply there's to help the t-shirts accelerate. When designing this robot, we knew the risks of PVC. The only pressure they have to support, I guess, is the back pressure from the t-shirt. This is way less than 80 psi and the team and mentors believe it to be safe.

Originally Posted by waffle_dynasty (Post 1620534)

5010 has worked hard these past few weeks to get a working robot. Everything's pretty much come together except for a few nuts and bolts.

See a video here: https://youtu.be/NZGkK7Itcko

We've still got a few things to tinker with before we officially call it finished, but here are some specs:

• 6 t-shirt rotating barrel

• Car jack angle adjuster

• 6 wheel pneumatic drive

• SCUBA tank shooter

Originally Posted by IndySam (Post 1620609)

This ^^^

PVC is bad bad for storage but perfectly fine for use in a barrel.