pic: Team Fusion's T-Shirt Shooting Robot

[billbo911]

Originally Posted by Andrew Blair

Where did you guys buy your pvc tank?

We built our own. Drop a few $$ at your local hardware store and your in business. For example: (3ft. X 4in. ID SCHD 40 PVC) + (2 end caps) =~ 450 cubic in. pressure chamber. (3ft. X 3in. ID SCHD 40 PVC + 1 end cap) = 1 3ft. long barrel.

See a pattern developing? This is a classic case of DIY t-shirt launcher.

By the way, thanks again for the inspiration Team Fusion!!!


After writing this response, I realized that 364 is from Gulfport, Ms. Are you guys alright down there?? Did your school and robotics stuff survive? Is there anything we can do to help you out?

[Andrew Blair]

Originally Posted by billbo911

We built our own. Drop a few $$ at your local hardware store and your in business. For example: (3ft. X 4in. ID SCHD 40 PVC) + (2 end caps) =~ 450 cubic in. pressure chamber. (3ft. X 3in. ID SCHD 40 PVC + 1 end cap) = 1 3ft. long barrel.

See a pattern developing? This is a classic case of DIY t-shirt launcher.

By the way, thanks again for the inspiration Team Fusion!!!


After writing this response, I realized that 364 is from Gulfport, Ms. Are you guys alright down there?? Did your school and robotics stuff survive? Is there anything we can do to help you out?

No, I meant the pressure vessel. I'm not sure I'd want to build my own tank, but I'm sure it can be done.



-----------EDIT-----------------------------------------
My bad, I didn't thoroughly read your post. Thanks for the info! I guess I listened too intently to the "do not build air tanks out of pvc or you'll die" thread!

[bhweezer]

We used the pressure valve from the 2004 KOP.

Sorry for not having any video of this yet. Katrina hit and things are still pretty crazy down here. The high school starts back tomorrow so I will head over there after class and try to get you guys some video of it. In all honesty I have no clue if this robot is still around. I think it went underwater during some of the flooding here.

[mechanicalbrain]

Originally Posted by bhweezer

We used the pressure valve from the 2004 KOP.

Sorry for not having any video of this yet. Katrina hit and things are still pretty crazy down here. The high school starts back tomorrow so I will head over there after class and try to get you guys some video of it. In all honesty I have no clue if this robot is still around. I think it went underwater during some of the flooding here.

Hey no problem, and I hope everythings okay.

[Andrew Blair]

Originally Posted by bhweezer

We used the pressure valve from the 2004 KOP.

Sorry for not having any video of this yet. Katrina hit and things are still pretty crazy down here. The high school starts back tomorrow so I will head over there after class and try to get you guys some video of it. In all honesty I have no clue if this robot is still around. I think it went underwater during some of the flooding here.

Hey, like has been said, I'm sure that shooting t-shirts is least on your mind right now. And about the whole underwater part, um, be careful please when you turn it on, if you do. Electrical fire=bad! Good luck to you guys down there, everyone is behind you.

[billbo911]

Originally Posted by Andrew Blair

...And about the whole underwater part, um, be careful please when you turn it on, if you do. Electrical fire=bad! Good luck to you guys down there, everone is behind you.

Well said!!!
I think I can speak for almost every user on CD when I say our thoughts and prayors are with you all down there!


Andrew, I think I missed something, you replied to my description with

No, I meant the pressure vessel.

I thought that was what you asked, and that is why I responded with what I did.

Oh wait, I just had a brain flash. Try this explanation.
We continually recharge our pressure vessel, or pressure tank, with the on board compressor from the 2005 KOP.

[Andrew Blair]

Yep, I got it, after I reread your post(read twice, post once....I know). My brain apparently stopped part way through, then picked up again on the how to make the barrel. Sorry about that, if you read my edit on the post I think it'll be pretty hunky-dory.

By the way, we are currently building our own t-shirst shooter!Yayyy!! And heres an idea we came up with: Our school uses really cheap, lightweight garbage bags in the small cans, and if the shirt(or other projectile of choice) is placed in the bag first, it slides much nicer in the pvc, as well as acting as a kind of sabot on launch. As far as the bags go, think of one of the plastic produce bags that are on the rolls and that you put your fruit in at the grocery store.

[mechanicalbrain]

Originally Posted by Andrew Blair

Yep, I got it, after I reread your post(read twice, post once....I know). My brain apparently stopped part way through, then picked up again on the how to make the barrel. Sorry about that, if you read my edit on the post I think it'll be pretty hunky-dory.

By the way, we are currently building our own t-shirst shooter!Yayyy!! And heres an idea we came up with: Our school uses really cheap, lightweight garbage bags in the small cans, and if the shirt(or other projectile of choice) is placed in the bag first, it slides much nicer in the pvc, as well as acting as a kind of sabot on launch. As far as the bags go, think of one of the plastic produce bags that are on the rolls and that you put your fruit in at the grocery store.

Thank you! This is eexactly what i recomended nice to see it works well. When you finish be sure to post pics!

[billbo911]

Originally Posted by Andrew Blair

By the way, we are currently building our own t-shirst shooter!Yayyy!! And heres an idea we came up with: Our school uses really cheap, lightweight garbage bags in the small cans, and if the shirt(or other projectile of choice) is placed in the bag first, it slides much nicer in the pvc, as well as acting as a kind of sabot on launch. As far as the bags go, think of one of the plastic produce bags that are on the rolls and that you put your fruit in at the grocery store.

Here is a bit of advice, we found this out the hard way.
When pressing the shirt down the barrel during loading, you might feel a large static field/charge building up. If you can feel it, it's already beyond the point that it could cause damage to static sensitive devices such as the FET's in you Victors. So to reduce or dissipate this charge, add a grounding strap , cable or chain to the bot to ground it. We added a short length of chain to the bottom of the frame. It drags on the ground and makes a huge difference.

[Andrew Blair]

wow, would have never thought of that problem... How exactly do you ground pvc though? I thought it only developed static on one side(blame television if I'm wrong), which would be the inside. Anyways, we will definitely do this. We have learned the hard way about not listening to suggestions............

[billbo911]

Originally Posted by Andrew Blair

wow, would have never thought of that problem... How exactly do you ground pvc though?

Our barrel is mounted to a metal section of our arm. We used a couple of large hose clamps, also metal. By looking carefully at the design of your bot, you should be able to determine if your attachment point is electrically connected to your chassis or frame. If it is, a chain or other conductor attached to the frame and dragging on the ground should suffice. Remember, high resistance in the path to ground isn't that big of a problem. For instance, an anti-static mat and wrist cord measure around 1 meg. ohm between the wrist-strap and the mat, and another 1 Meg to the ground clip. You don't need, nor necessarily want, a short to ground. Just make sure you have a conductive path from the barrel to ground that bypasses the electronics.

[mechanicalbrain]

PVC naturally generates quite a bit of static (I HATE having to brush all the dirt and junk that collects on them) and might not be the best choice. Unfortunately right now I can't think of a better material. Does anyone know exactly why PVC generates so much static? Ive worked with other plastics and I have never seen a more efficient hair collector.

[Andrew Blair]

One problem with the grounding, we will almost exclusively be using this on a polyurethane sealed wooden gym floor, or on a rubber track. We don't want to ground the entire frame to the battery, so how many shots do we get before we will start having problems? Or is there something like a static magnet? Or could we maybe just isolate the pvc from the frame?

[mechanicalbrain]

You dont have to ground to a floor. Any mass of metal will do. Even people will work!

[Andrew Blair]

So what you mean is, excuse my ignorance of all things electric, that even if i'm (and the bot) am on an insulated mat, wearing heavily insulated gloves; if i whack it with a piece of aluminum, I'm all set?