4" piston valve help.

[JDP12]

I'm starting work on my massive t-shirt launcher, with a 4" tee serving as the piston housing, but I'm lookin for some tips on the piston itself- any suggestions for what it should be? I tried a 3" endcap but there was a lot of space between it and the walls of the tee- so any suggestions?

Thanks.

ILTBTU

[SpudUke5]

Well i used a 3 inch endcap and it worked well, but there is still some roughness that i have to sand down because it doesnt always slide easily. But it still works.

By the way, do you mean the walls of the 4 inch pipe? not the tee. Try fitting the 3 inch endcap into a section of 4 inch pipe. Then when setting up the piston, glue in the section of pipe.

[JDP12]

umm... where would i put the pipe then?? diagram maybe- i saw your gun but how would i make it so the piston can slide in teh pipe- this should prolly be a really easy thing to figure out but i'm super tired right now, so you might have to bear with me right now, work was bad

[SpudUke5]

Yea i know what you mean, i worked today too, and it was in the morning

I really dont want to go through the trouble of getting a diagram so concentrate and imagine this:

You have a 4 inch tee in your hands. Now you take a piece of 4 inch pipe, and put it in the tee. Perfect fit.

then you find something that fits in the ID of the 4 inch pipe. Thats the piston.

[JDP12]

oh duh, so something like this?


and is a 3/4" QEV enough to pilot such a massive valve, or should i have two??

<img src="http://i157.photobucket.com/albums/t79/ ... 1217974880">

[brogdenlaxmiddie]

It will pilot it but I'd go for two to make it faster

[SpudFarm]

that has really small frontal area on that diagram ....

[SpudUke5]

Yes, thats what i was talking about. And i used a 3/4 inch qev so i dont see why you cant.

[JDP12]

spudfarm- it was a 30 second drawing. wasn't mean to be accurate in any way at all...

cool..only now i have to order new parts because... basically i want more power than i did when i made the first order :D:D

do you guys think a 4 inch 2 foot long chamber will provide sufficient power???

[SpudUke5]

Sure, but it wouldnt match my power

[JDP12]

lol i might go bigger idk... budget dependent..

[Gippeto]

Have you concidered somethng like this?

It pilots very nicely with a modded blowgun.

The idea could be scaled up to what you need.