Help with 'rocket launcher' design

[Pilgrimman]

I would stick with a sprinkler valve first. You can always convert to a piston valve later. I can't wait to see some vids of paintball ownage! Welcome to Spudfiles!

[Marlowe]

Well guys, sorry to let you down. Been very busy lately with play rehearsals, and when I'm not at school, wrestling practice, or the gym, I have to try and make time for my friends (who all seem quite neglected). However, with the holiday season upon us and break almost here, I may be able to do most of the work over the holiday season. I have updated the plans to include a Schrader valve (for safety, letting excess pressure out instead of exploding) and a pressure gauge( to see just how many shots I have left. So, not having anything else to ask you, I would like your opinions on a small project I'm working that is quite far removed from most Spudguns. This being *cues drum roll* TRIP MINES AND TANKS!!! You guys caught me starting out on a very dumb school project known as "The Senior Project". Basically, you research and do what ever you want, but you have to have mentors to help you along the way (by the way, thanks Judgment_Arms). So, my idea was to make a bunch of paintball exotic weaponry that not many see too often. So, while you continue to help me out on this front, I would also like your input on the other facets of the project.

The first picture is the mine, a lowly pressured little hunk of PVC with some surgical tubing glued in it. The whole thing was pretty much designed by a poster on another board by the name of Johnny Law (the forum topic on this can be found here at http://forum.leiningerarmsworks.info/ph ... ?f=25&t=24. Hopefully, the air pressure will give it a little more kick when the paint comes out of the surgical tubing, but I still can't figure out how to void it of air when I need to refill it with paint. Any suggestions?

The image below the first one is a very simple sketch of the frame I'm going to make for the tank. When finished, two layers of heavy canvas will be put across the whole thing, and give it some walls. If you don't quite get a good idea of what it'll look like, then check out some pictures of the M1 Abrams tank, I wanted to make mine look very similar. It's powered by a bicycle, which I in turn power, and should be pretty light if my calculations are correct. I'll be mounting a larger breech loading spudgun in the turret where you see the gap is. I flirted with an automatic turret for a little, but chalked it up as too complicated. Even if I could end up getting it, I would have to explain it to a board of teachers with no background knowledge of anything spudder-related. Drawings for that should come shortly.

Some other stuff I'm up too spudwise:

Designing a shotgun like break away launcher for a friend, probably using the same gun parts as we all know and love from my earlier posts, just subbing out my slide for a breakaway loader. I got a good idea of what it'll be, but I could use some input on it when I get time to draw up the plans.

Another project I'm working on, thanks to psycix's pilgramman's urgings, is a piston cannon that I will use as a sad attempt at a paintball pistol. Again, drawings will be posted as soon as I make them.

Thanks for reading through this whole thing, and I hope you can get me some help with it soon. Thanks a lot guys!



Edit: In a flash of sudden smartitude, I figured out a way to get rid of the small amount of pressure that the mine will have. Instead of mounting the Schrader valve directly to the PVC, I'll hook it up to a quick release that gets stuck on the mine's body. I fill it up with the schrader, then take it off and the air goes out. Now the only problem is, how to graft the Schrader onto the quick release safely. After all, that is a pretty big thing to school officials...

[Marlowe]

Well yall', we seem to have run into a dilemma. Apparently, some of the parts that I was looking for are very hard to come by. So, I've had to revert back to my original single-valve system. If any of you guys are able to find the parts I was looking for, I'd love for you to let me know. I've also had the idea to put lettering on the side of the loader, made out of excess PVC piping. So, while we're here, I might as well show everyone the price list. Some of this stuff I readily have at my house, but for when I put this in the finished cannon section, I figured i should have the prices ready. I know the whole thing comes to about $100, but i think it'll be worth it.

Required

1x Lawn Genie RJ 3/4 In. In-Line Valve (Female Thread) $11.97
1x Husky Safety Blow Gun $5.98
1x Husky 1/4 In. NPT Male Hose End $3.28
1x TWI International 1/2" x 520" Teflon Tape $2.97
2x Stainless Steel Hose Clamp 5/16 - 7/8 inches $1.50
1x 1/4 Male Air Coupler x 1/4 MPT $1.39
4x PVC 1"x 2" close Sch 40 or 80 nipple ~$4.70
1x PVC 1"x 1" / 2" 1/2" Male Sch 40 or 80 Coupler ~$5.50
2x PVC 2"x 36" Female Sch 40 or 80 pipe ~$17.00
1x PVC 2"x 4" Plain End Pipe ~$3.50
1x 3 Washers,6 bolts,3 screws,1 strip of aluminum flashing~$3.00

Required Subtotal $60.79
Required Tax $4.26
Required Total $65.05


Optional

1x Straight air hose, no idea where to find it. ~$5.00
1x Utility Gauges For OEM Markets Dual psi/bar Scales $22.50
1x PVC 2"x 4" (For the embossed lettering) ~$3.50

Optional Subtotal $31.00


Grand Subtotal $91.79
Grand Tax $6.43
Grand Total $98.22


Also, I finished with a 3D design of the tank, and I think it looks really good. I'd show you, but my computer's been really screwy lately, and can't locate the picture files. I hope to finish this cannon by the second week of January, and then it's on to making that paintball pistol.

[pocket]

If u want a more compact cleaner way try this http://members.tripod.com/potatogunwarrior/zooka.htm i find that over and unders are a pain in the ass and once again you should go with a barrel sealing piston! not just will it be more compact it will also have a much higher performance rating

[Marlowe]

I would do a piston, but the seem to shred the tails off of nerf rockets, and I'd imagine that would leave their accuracy quite a lot to be desired. Also, the reason I'm doing an over and under style gun is to make it more compact. I'm looking at a fairly small weapon, only about 3' 1/2' feet long, and require quite a long air resevoir to fill up safely.

[pocket]

yes a barrel sealing piston has the barrel inside the chamber thus if u wanted it 3 1/2' long then you would have both the barrel and chamber 3 1/2 feet long here is a cannon with the same design that im talkin about http://www.spudfiles.com/forums/paintba ... 16728.html

[MrCrowley]

I would do a piston, but the seem to shred the tails off of nerf rockets, and I'd imagine that would leave their accuracy quite a lot to be desired.

That also happened to me, I just used some araldite to epoxy it back in and it hasn't come off since.

[judgment_arms]

I would do a piston, but the seem to shred the tails off of nerf rockets, and I'd imagine that would leave their accuracy quite a lot to be desired.

That also happened to me, I just used some araldite to epoxy it back in and it hasn't come off since.

But we're not allowed to do that.

All NERFs must be unmodified except for the writing of the owner's name on the bulb.

[MrCrowley]

I would do a piston, but the seem to shred the tails off of nerf rockets, and I'd imagine that would leave their accuracy quite a lot to be desired.

That also happened to me, I just used some araldite to epoxy it back in and it hasn't come off since.

But we're not allowed to do that.

All NERFs must be unmodified except for the writing of the owner's name on the bulb.

Not even araldite? I'm sure no one would notice

Anyway, this is at 80psi. With a piston valve, 30psi is more then enough with a reasonable sized chamber and leaves the nerfs intact.

[judgment_arms]

Not even araldite? I'm sure no one would notice

Legally, we can't use it.

Anyway, this is at 80psi. With a piston valve, 30psi is more then enough with a reasonable sized chamber and leaves the nerfs intact.

Perhaps, but my cannon's barrel is just long enough to stuff a NERF in.
It's loud, inaccurate, and LOUD (not redundant), but it's small, light, fast to reload, and loud enough to scare the paint out of somebody!


there's a balance between Small and Effective:
Small is just that, small, light, compact, sling it over your back and carry it all day and not mind too much.
but it's inaccurate and loud.

Effective is accurate, quiet, and fast to reload.
but it's heavy and awkward.

Most of the time people balance these out, but my cannon is on the extreme end of the Small side, to the point that it's back to being Effective.

[Marlowe]

Well, yet again my parents throw a wrench in the gears of my plans. So, it looks like I won't be able to buy any of the supplies till after newyears. Sorry everyone, you have no idea how often they do this sort of stuff. Any way, my computer let me find those tank images, and I ofcourse made some changes to all of the measurements that I had written down. While I'm here, for my paintball pistol, what materials would you reccomend? I was thinking brass or steel, but I'm not sure. Also, If you could recommend a small barrel sealing piton that I could look at, that'd be great.

[inonickname]

http://ourworld.compuserve.com/homepage ... tindex.htm

Just build a clark cable launcher as a gun so it can be fired horizontally. If the rocket arcs up look around for a method to use a balloon for straight horizontal flight. Even a standard 1-2 L bottle will take a heavy payload. My homebuilt launcher uses 3 jaws to grip the center bottle. It has 2 launch tubes for additional fall-away boosters, which are adjustable. Each launching tube can be pressurized and fired remotely. (uses servos @ a waterproofed rc unit). That's way too heavy to carry around, but i might build a smaller rpg type obe.

Your design would work anyway.

[Marlowe]

Hey guys, finally got the main idea for the pistol, but I have a little problem. In my want to make it a multi shot pistol, by my understanding pretty undoable using piston valves, I've made a pretty interesting air resevoir set up. The problem is, I don't know how to make it seal from the rest of the gun whenever i need to shoot. If I connect it to the chamber, then all of the air will get sucked out in the shot, making it an undesirable single shot again. If i connect it behind the piston for air flow, then the piston won't come back when i take a shot. I can't use a slow pin prick leak for the chamber hook up, as it wouldn't fill the chamber back fast enough for another shot. I'd have the same problem if I tried it with the rear piston hookup. So, I could really use some help, if anyone cares to tell me where I whent wrong in my design, or can help me rig up a suitable valve. Mind you, that this must be operable with the pull of one trigger, or one hand (easily) at the least. I'd like for it to retain it's overall shape, but if you guy's have a better idea, then sock it to me.

P.S. The ball valve is being used as a safety

EDIT: Sorry inonickname, I didn't see your post before I put mine in. I would use it, but that would make the gun illegal, atleast in paintball terms. We have to use NERF rockets, much less painful than anything else.

[Mateo]

wait. are you talkin about buildin a full size tank? that people can go in and shoot out of? if you are i found this in a popsci magazine a little while ago and it looked pretty cool.

http://www.popsci.com/diy/article/2008- ... red-panzer

of course it cost them $3000 dollars to make so maybe dont make it that big but it would be cool to have one outfitted for paintball

[judgment_arms]

Marlowe, I believe you're underestimating the bulk of you material.

You really should get over to my place sometime soon, I'd love to offer more help on here, but I'm too busy to take the time and type up everything...
Okay, actually it's more I'm too lazy but...