Recently having looked into the field of cylinder head modifications it has crossed my mind to apply some techniques that are used in engines and use them on a sprinkler valve!As the valve itself is the largest bottleneck between the chamber and barrel. -Adding material to reduce turbulent pockets.(...

How much thrust is this little engine putting out?

Nice launcher love that valve what is it rated to?Damage pics?

It helps to relocate the diaphragm to its seat,without it the diaphragm can actually get "stuck" on the side of the seat and the wall requiring the chamber to be removed and the diaphragm manual seated(very annoying) so the chamber is sealed,sealing also becomes an issue with the spring removed as t...

So with all this machining gear about has someone taken steps to rifle regular PVC pipes with reasonable tolerences and repeatablilty that doesn't cost an arm and a leg?

15,000 posts....A few to read!

^^What he said,been in it a while.^^

Or,get to know your local plumber supply merchant

Spudder still at heart,although it must have been a month or two since I have touched one.

Computer solenoid actuated fuel injection up your alley then paaiyan?



Now I'm going to see what useful info I can find in these 20,000 odd posts

I've experienced an explosion or 3 with PVC,Pressure pipe and DWV.

Safety pressure ratings are there for a reason,Follow them!

DWV is designed to take a small amount of pressure (gravity mainly) but personaly for anything other then a spray 'n' pray combustion I don't trust it.

Good old flint twister style,what I wouldn't do for one of them over here in Aus.

Reliable,cheap and easy to replace parts.All the things you want in a first launcher.

Sonic boom from a trebuchet,so like a giant whip?That would of been impressive


When I make my move to indonesia,there's going to be a chunkin.Don't think we have many indonesian spudders though...Hmmm

Now this has me interested!

So you are going for a push die style of cutting (correct me if I'm wrong) If memory serves correct then this will be a slow process.Have you thought about the pipes OD changing from the machining process,such as "ballooning" of the pipe.

Go 300

Might be a bit of a stupid question,but whats was your rough estimate on building this?

I know,thats the only thing I could put it down to.

My dremal also broke,but mine was a cheap rip off worth about $20.It lived a rather long life though.

Impressive.I like the stock,I'm giving up on these small pistons,again....I'll just settle for a QEV when I find one thats not to pricey in Australia.

Yeah,thats cool.Now get some sinkers!Really watch that baby do some damage.