SpudFiles

So I've been working on an airsoft mortar and i have run into some noob problems. The first model i made had a 12' long section of 1" pvc for the air chamber with a 24" long barrel (also 1" pvc.) It didn't shoot very far with about 60 pounds and I decided that my problem was the air chamber was smaller than the barrel. My question is if my decision on the problem was correct and i need to make a bigger air chamber or if I'm sadly mistaken?

Thanks,

jwilson7

Well there could be several problems..

1. What is the valve? Is it a ball valve? sprinkler valve? etc?

2. 60PSI really is not that high of a pressure.

3. I'm assuming that you are firing airsoft BB's because of the diameter of the barrel. They are too light to really travel far via an air cannon especially at 60 psi.

4. Are you using any kind of wading or are you just pouring bbs and firing?
If you don't use wadding you will get too much air blowing past the bbs rather than pushing them.

5. Just in case, cause I have a feeling, please visit this link for safety:

http://www.spudfiles.com/spud_wiki/inde ... _Rated_PVC

The valve is a brass ball valve with a fancy spring set up that my grandpa showed me to make it release fast because i didnt want to spend the money on a sprinkler valve.

As for the bbs, i cut an old highlighter marker tube in half and i pour the bbs into that and then wrap a rag around it to make it airtight.

And I had already checked into the whole pressure rated pvc thing and i made it out of that.

are you launching the highlighter marker tube as well?

Id assume a lot of fields would not approve the device if it launched the highlighter tube as well...


try putting some wadding in first.. then BBS and try firing that and only that.



Other than that, 60 psi is pretty low when considering your chamber size. If everything is pressure rated, you could easily go to 120 psi which should be satisfactory or even higher.

the lowest I have seen pressure rating for 1" sch40 NSF-PW pipe is 270 psi and I have seen as high as 450 psi.

But overall 120 psi should be more than adequate power with a good safety margin.

with all due respect jwilson a 1" brass ball valve is going to cost you about as much as a sprinkler valve
also since you already have the valve get one of these http://www.rap4.com/paintball/os/quick- ... -3506.html
upgrade to a galvanized steel chamber about the same size as your current one and get a larger barrel so it can be used for multiple roles and will pack quite a bit more punch

I already had the ball valve so it didn't cost me anything

I do launch the highlighter marker tube, but it splits right after launch and only goes about 5 feet, besides all the games I play are unofficial.

The barrel has a male threaded adapter so I can use any size barrel I want.

I will start trying some higher pressures and maybe that will do the trick but do you think a bigger air chamber will give me more power?

jwilson7 wrote:I already had the ball valve so it didn't cost me anything

I do launch the highlighter marker tube, but it splits right after launch and only goes about 5 feet, besides all the games I play are unofficial.

The barrel has a male threaded adapter so I can use any size barrel I want.

I will start trying some higher pressures and maybe that will do the trick but do you think a bigger air chamber will give me more power?

uh if you read my post i would say higher pressures with the same sized chamber would be better although you would have to make it out of metal if you want like 400psi and upgrade to a wider barrel since you since you don't want to injure anyone.

but yes a bigger chamber like a 2" one of the same length would give more satisfactory results at 60psi

Okay thanks for the help Cool Hwhip ( love the name by the way) and thanks Davidvaini.

I think this is the critical point:

Davidvaini wrote:3. I'm assuming that you are firing airsoft BB's because of the diameter of the barrel. They are too light to really travel far via an air cannon especially at 60 psi.

If you want range, then the BBs are going to have to be travelling very fast when they leave the barrel as they slow down very quickly, so if you're unwilling to change the valve or go for a longer barrel, upping the pressure is really the only option.

yeah i have fire bb's out of my 2 inch piston cannon in a shotgun sabot(not really a fair comparison) and they can easily hit something 60-70 yards away off a straight shot

what did you use as wadding for the shotgun sabot?