SpudFiles

@pyromanic: in any situation I don't think lowering the pressure will ever increase the speed, I believe the direction to obtain this is a smaller bore barrel

Would a big piece of PVC with end caps on it work as a chamber

of course
tell us are you attempting multiple shots or single shots?
what type of valve are you planing on using?

I also had an idea, you could try using an aerosol duster, it might work cause it sprays air faster then you can blow, then again it just might lack current, since current direct better then manual blowing

iknowmy3tables wrote:@pyromanic: in any situation I don't think lowering the pressure will ever increase the speed, I believe the direction to obtain this is a smaller bore barrel

what i mean is ge up to 10 psi with yoru breth useing the check valve then open the ball valve and you will have a faster shot then with yoru breath.

Multiple shots would be cool, but I'm not too sure how I would go about doing it so most of my ideas at the moment are for a single shot.

I think I may go buy a sprinkler valve and mod it. I saw a tutorial on how to do it, and it seems to be the best preforming valve for pneumatic guns.

My local hardware store also has some great ball valves, but I've never bothered checking if the threading on them is compatible with PVC pipe threading.

what i mean is ge up to 10 psi with yoru breth useing the check valve then open the ball valve and you will have a faster shot then with yoru breath.

its less then 10psi, and the check valve has a cracking pressure which takes presure away and their isn't enough air in a few psi. to work that you should have a balloon to get low presure higher volume, I've tried it in a foam dart blowgun not very good, you should try long hot dog balloon or water ballons filled with a low pressure pump.

ok now jeho sprinkler valves are like $20 they are great, but it's really overkill for a marshmallow gun, unless your planing on other projectiles like batteries, marbles and spuds which would be totally awesome, but a ball valve is already a lot for marshmallows. the valves should work thanks to the NPT(national pipe thread) standard which is the same for almost all pipe materials

Pfft 10psi, I'm going to get some serious pressure behind this gun.

I like the idea of batteries as a projectile they would fit perfectly.

I think I may end up modding a sprinkler valve anyways because the entire point of me making this gun is overkill. I can reuse it for future guns. I plan on making guns for larger projectiles in the near future. If nothing else, this will be good practice for modding valves.
Thanks for the bit about the NPT it's good to know, and I've never heard of that before.

Jumpin Jehosaphat wrote:Pfft 10psi, I'm going to get some serious pressure behind this gun.

the point of this is to not need a bike pump but your would have higher pressure then jsut blowing once.

It's an alright idea pyro, but I have access to an air compressor, so I will just use that for now.

Very nice. Ive made a marshmallow gun, but not bolt.

Bolt isn't too important (just cool) because marshmallows will travel along curved paths, you can just stick 'em in the mouthpiece of the gun and they will work fine.

The bolt action is actually useful to me now because I have converted this gun to use pressurized air. I got it over 100 psi. It really sends those marshmallows fast and far considering how much the wind interferes with the light weight projectiles. I also lowered the scope about an inch. I use a modified sprinkler valve, I used something a little different from a traditional blowgun for the trigger, I'm sure you will like it.

The rifle looks rather different, and operates using a completely different system. I will post a topic for the high powered marshmallow rifle in the near future; keep an eye out for it.