SpudFiles

im making another pnumatic co-axil canon and i was going to use this design and was wondering how to mod the valve for blowgun piloting?is it the same or do you have to do something else,or can you only do it with inlines

My understanding is that that style of sprinkler valve doesn't work as well as the inline style; you'd be better off using an inline valve and a pair of 90* elbows.

now where would i put the valve on the bottom or on the top and wat should i use for 1.5" or 2" elbows?

To eliminate dead space, put it on top. As far as elbows go, I built one similar and used 1" elbows (that was the size of my valve). This kept the chamber closer to the barrel, and were a lot cheaper than 1.5" or 2" elbows. Just make sure to reinforce the barrel to the chamber to keep stresses off the elbows.

ok i get wat u mean thanks

also how do i make a cheap bolt action i was going to just cut a hole in the end of the 1.5 INCH barrel and put a 1.5 INCH coupling with the edges removed from the inside

It's probably best to put the valve on the bottom, as it allows for more barrel length for the overall length of the launcher... but you'd best model both situations to be sure.