piston question

Check out my YouTube SpudGun Channel! · Mon Jan 07, 2008 10:38 pm

I thought chamber was 1.5"?

Blowgun would be pushing it, PVC ball valve would have more power.

Nope sounds good.

Make the piston after you've got the parts, then you can make an effective piston that takes up as much pilot volume, has 1/4 of the barrel diameter as a run up and is light but strong.

Isomer · Mon Jan 07, 2008 10:52 pm

I actually think the blowgun would work well. For starters, a coaxial with a ball valve pilot is hard to shoot accurately (friend having this exact problem atm) and it doesn't quite give the ergonomic feel that a blowgun does. If you make the piston well-small pilot, small travel, fast, and OD close to ID of piston housing then the blowgun should be alright
EDIT: As somewhat of a go-between you could mod the blowgun for higher flow

Check out my YouTube SpudGun Channel! · Mon Jan 07, 2008 10:56 pm

Yes isomer is correct, if you make a good piston, blow gun will work.

If you go 1.5" or 2" chambered, then a sprinkler valve could come into play. Maybe a 3/4" sprinkler valve if you went with a 1.5" chamber.

spudy buddy · Mon Jan 07, 2008 11:03 pm

well this is gone be my first piston gun and so just a prototype with the pipes i have and those are 1inch and 1/2inch just so i can see if i should make a real piston gun or not if after a lot of trile and error i still cant get it to work. if it works i wil make a biger better one.

Isomer · Mon Jan 07, 2008 11:12 pm

From personal experience I think it's better to start with a larger diameter piston to learn really well what's actually going on. It's also easier to work with a bigger size, not too many people have the really fine scale tools required for precise small pistons.

1" is plenty big, im just saying that it's better starting with that than say a 0.5" one!

spudy buddy · Tue Jan 08, 2008 6:59 pm

well isn't 1inch big enough? even if it isn't i'll still use it cause i don't have anything else and my parents won't let me buy more pipe for awile.

edit: oh ok i thought you ment like a 2inch piston so i was geting woryed lol

edit: i have another questoin. idk if everybody knows what a jack in the box ball is but i was wondering if a piece of that would work as a sealing face???

Check out my YouTube SpudGun Channel! · Tue Jan 08, 2008 7:04 pm

Not sure what it is, but you said it was a ball, that could be difficult to use as a sealing face.

spudy buddy · Tue Jan 08, 2008 7:18 pm

it's a big ball that you put on your car antena and is made of pretty hard fome. i would cut a slice off and use that not the whole ball. its about the size of a golf ball but without the dimples

Check out my YouTube SpudGun Channel! · Tue Jan 08, 2008 7:24 pm

spudy buddy wrote:it's a big ball that you put on your car antena and is made of pretty hard fome. i would cut a slice off and use that not the whole ball. its about the size of a golf ball but without the dimples

Hmm because it's foam, its porus and may leak.

Just go with a rubber gasket or neoprene or a bike tyre inner.

SpudUke5 · Tue Jan 08, 2008 7:37 pm

You can simply mold a piston to for your seat. If the pipe is 1.5 inches that goes in the tee, just mold that with some hot glue, and use a lubricant to get it out. Then bolt the sealing face on the even part of the hot glue piston with a bolt and a washer. Its easy. If you cant find stuff to make a piston, it can be easily molded. Like this one i made is very reliable, but if you havent used it in a while, you would have to relube it.

And dont forget the bumper, which is what the picture is above (pool noodle)

spudy buddy · Wed Jan 09, 2008 8:34 pm

ok well i haven't gon to the stor yet so im just thinking about a sealing face alternative untill i go to byu the fittings. if i come up with something, great, if not i'll just buy a gasket. by the way when i cast my piston i plan on puting in a bolt nere the top so that i can easily atatch the face.anything wrong with that?

also does the bumper need to be atatched to the piston or can it be atatched to the cap?

Check out my YouTube SpudGun Channel! · Wed Jan 09, 2008 8:48 pm

No that's fine, but you'll need a washer on the bolt otherwise the sealing face gets sucked off the bolt, trust me it happens.

Though sometimes you get a leak between the bolt and washer where the air goes through the two and escape out the barrel, to fix this you just put some epoxy on the bolt around the washer or something.

Can be attached to piston or end cap, doesn't matter.

spudy buddy · Thu Jan 10, 2008 5:32 pm

kk ty and i'm thinking about making it a bb gun with all but the barrel the same but i have a question about bb barrels. when it says to ure brake line it meens the ones on cars right? but i se them online sold in coils??? can you straiten them out or will they never be perfectly strait? and with a barel that snall how do you atatch a sealing face? or does the piston have to be rubber for that to work or do you stick the face into the hot glu right when you cast the piston? sorry for asking so much

but i want to make it just right.

Check out my YouTube SpudGun Channel! · Thu Jan 10, 2008 5:39 pm

Brake line is found on cars and sold in coils.

Just cut a piece of and roll it on the (flat) floor until straight.

With a small barrel you don't need a bolt, just glue your sealing face on.

spudy buddy · Thu Jan 10, 2008 5:54 pm

oh ok and whats the minim length they sell it in and does it keep its inside diameter when it gets coiled couse i would think it would get distorted? and its cheap right? also what material is made of copper?