I have a neoprene disk already (I got rolls of the stuff), it does a great job as wadding (or atleast it looks like it will.


this launcher is only being used once, so I just want to make sure that I'll have enough force and volume to push the toilet paper up

OK heres the plan, I have a nice Solenoid comming (off an older firetruck for their sirens) rated to my specifications with nice flow.

I need to launch a Toilet paper roll(s) but Im not sure how much push I'll need to get them out of the barrel:

heres my setup:

2 older SCBA tanks pressurized to ...

hmph... way to necro a rather old thread.

also Im glad you chimed in, but is conisidered general knowlage that you cant break the sound barrier with compressed air, I beleive it may have been noted in this very thread (prior to your statement)

lol I was thinking the same thing but i dint want to say it.

also on a side note, I have decided (under your advice) to put off this project due to the dangers involved. Im going to make a few more pnuematics and maybe a cool combustion instead

if a mod reads this: this thread can be closed/locked

I have all the parts on hand to make the metering and firing systems (+/- a ball valve or two)

If it can be done with air (such as with Joels cannon) I will use that (safer?) route.

Thanks you all for your patience and understanding toward my stubbornness

*a quick edit* is there any mroe ...

as informative as that post was I did know most of that regardless im thankful you guys are so hesitant


I notice your a firefighter, Im a firefighter too :D got my emt-1 aswell :D

external firing boxes are easy as anything to make. I ahve a few setup for lighting off fireworks with NiChrome wire ...

other than stepped up saftey precautions is ther anything special needed for a hybrid?

I can weld pipe if need be.


after reading all the material i can find here on spudtech i have only a few more questions:

what kind of PVC are people using? it has a dark grey color to it, I've heard cpvc ...

Hello there! Its summer and that means its time for yet another devilishly destructive project to keep me busy. This year it comes in the form of a supersonic golf ball! (Well, at least that’s the plan)

Here’s the premise:
The goal of this project is to have the projectile (golf ball) reach the ...

Me and my friends did one of these for an engineering project. we started with 500 1\" square mirrors on a sheet of plywood. it soon grew out of hands because for each mirror tile we needed two screws to adjust it and a hole for each screw. we did build it (though it took us forever!) it wasnt very ...

I went shopping for PVC fittings for a new gun today (I'm going camping this weekend and wanted something fun to play with)

I first went to home depot, however much to my surprise they didn’t have rainbird valves or anything rainbird for the matter. Rather they had A self of the standard ...

yeah but do be careful with putting an air gauge on there, you will need to tap your hole (which requires a special tool set)

to tap it you need to use plumbing taps, not standard screw taps

when you put the teflon tape on wrap it tightly around the threads in the opposite direction of the threads ...

I wouldn't be too concerned about the fuel in the reservoir catching, regardless of how full it was.

consider this, the fuel (for whatever reason) starts coming out of the barrel at a slower rate and because the barrel is no longer saturated with fuel the flame can now come in. providing there ...

Mini marshmallows are fun to shoot

the problem I run into is that they seem to be too small for a 1/2 barrel though perhaps different brands are different sizes.

with my air canon they still make a 'thud' noise at ~40 feet or so but their preformance still seems to be lacking

ah, that explaination makes a lot of sense, I didn't consider that

I've been looking around here and have found a number of guns that feature two compression chambers. I understand that this increases the volume of compressed air the gun can hold but how could you use that extra pressure effectively?