Cheers for the advice dudes ^^
Alrighty, Had a day off today so a few things got finished before the big testing weekend. Main job was to sort out that leaky QDV pilot valve.
Those plastic taper thread end caps appear to be the most non airtight devices ever conceived, so a metal bung was needed to seal it up for good. I'd already bought a 1/4BSP tap but only found out after using it that it's a taper tap not a straight through one, and at $23 a shot wasn't prepared to get another one.
So doing what any dodgy back yard engineer would do, a quick disconnect was gutted, cut apart and welded in to make a $4 threaded bung. Works great too!
If you ever wanted to see the inside of a QD nitto style fitting... Quite ingenious with the floating seal. If the spring was taken out, i wonder if you could make one into a little piston valve?
But anyway, The bottom was cut off, and lathed down to press fit into the top of the QDV body, the faux-chrome was ground off and the thing welded in albeit hideously lol. No doubt, chinese fittings and chinese made galvanised pipe was never made to be fused. But too bad!
Black paint covers all sins... >.>
Added bonus in that the bung takes up heaps of pilot volume inside the qdv inlet. Never a bad thing. After that the end cap needed a little chunk milled out of it so the bung wouldnt rub on it. Easy done.
The valve work all ready to go.
Works much better again then it has before. And no more leaks. Can't complain about that
Only problem is the spool doesn't seem to open completely when its fired, even though the time from opening the qdv to the cannon firing is next to nothing.
That would be because I'm a retard and didn't put any vent holes before hind the spool. So it would quickly open then rebound again. Quickly sorted that one out with some 2mm holes drilled in the back of the valve body.
I'll test it tommorow but fingers crossed it slams open and stays that way. Not sure what it would be if this doesn't sort it considering the spool moves super freely. Perhaps without a projectile there's no real force to push the spool open?
But after that not much else to do with this toy. Going to 3d print a muzzle brake and attach all the compressor/battery/brace stuff and machine that new rear plug when the delrin comes and that's this project done with. I might toy around with surface casting hollow pistons to see what effect reducing the weight to extreme levels has on performance, but that'll be it.
Have to think about what to make next. I'm thinking of finishing the QDV metal cannon and firing that at as high a pressure as the brushless compressor will pump it up to (500-600psi hopefully). That should be a super quick build.
Definitely need to make a hybrid too. My friend wants to make a "deiseling" cannon that uses two co ax chambers, with a pilot valve in the outer one firing a metal ring down the inner co ax chamber @ ~1000psi to compress and combust a mixture that will fire the projectile out via a burst disk. Sounds cool enough to at least attempt as a partnership
Grabbed some 65mm diameter bright steel rod for my own hybrid burst disk cannon. I reckon a straight copy of this cannon (http://www.spudfiles.com/forums/lardas- ... 15524.html
) will be a good starting point, given its fairly easy to machine and super over built.
That's it for now. Definitely a few damage videos on the way