john, you might want to start a new thread when discussing a new topic - many people will pass by this thread title if they have read it before or aren't interested in the title, in which case, most forum members won't see your question... unfortunately, i don't have experience with hammer valves. w...

yes, using a Cv of ~6 worked well in predicting the velocity over a range of pressures for my tests. please keep in mind that the 3/4" QEV was piloted by a smaller 1/4" QEV (as described in the post mentioned above), and that seemed to make a big difference in the way the 3/4" fired. i didn't do any...

thanks! the black strips are temporary - grip tape like for hockey sticks. comes off easy. that is there only to hold the pieces together for initial fitting. btw, it is very comfortable to hold - the way the bottle hangs off the bar, along with the back end of the bar, makes for a great shoulder st...

...will have to get this done before the West Point Fall Scenario Game, comin up quick ~Sept 20. i'm getting an ASCO 3/4" for the final build :D (published Cv 10.5 !!!!!) those are Deltrols (3/4" and 1/4") in the pic below. some specs for the new build are captioned with the picture. the WhumpGun th...

*drool* oh cool! thanks - that'll be interesting to work with! i'll have to make a mortar next for your field!!!

6646K11 Quick-Exhaust Air Valve 3/8" Inlet, 3/8" Cylinder/Outlet, 3/8" Exhaust In stock at $13.08 Each p.s. stay away from the 1/4"x1/4"x1/4" QEV for - it's made by Mead (Mead #1B QEV) and i mistakenly bought it - i never used it (gonna return it) 'cause i can hardly blow input air into it & can't s...

you can get a 3/8" Deltrol QEV from McMaster.com for about $12. i'll see if i can get the McMaster part # for you. (BTW, i recently just happened to take a picture of mine before i polished cleaned & lubed - i'll dig that up too).

(sorry if this offends anybody, but posting a reply is the only way i can see to bump the thread so the forum shows updates to this thead. simply editing one of my previous posts doesn't trigger a bump...) Update: added pictures to the first post, progress to get the gunstock portion to this point:...

well, i want to add pics because it's easy, but replies don't allow upload, and i don't think editing the first post triggers an update ('bumps' the thread) - so in addition to adding a pic to the 1st post (the only one i can unless i host the images elsewhere), i add a reply to bump the post. am i ...

update: found the perfect trigger. i added a picture of the planned trigger mechanics on the first post in this thread.

update: build is coming along - the system holds 90 psi, but the compression fittings i'm using to the trigger/safety assembly leak. i'm headed to the store to get some flare fittings. if that doesn't work, i'll try paintball gun braided line next. good this is that the trigger mechanism works great...

keep it up! - we can see you're really trying to learn. p.s. lol i just have to ask (j/k here) - did you name the JPG "newdesign_137"? and if so, that wasn't your 137th sketch, was it?! ;) it occurred to me that if so, that's dedication! [edit, added:] p.p.s. where have you used qev's before? paintb...

well, that was a pain in the a$$. the first joint (1-1/4 soc x 3/4 NPT) went perfect - i thought it would be the harder one. i messed up the cap end 1st try & had to clean off the end & try again (just used a new cap, didn't feel like cleaning the used one). didn't go as good as the first, but it to...

thank yoyu - it's taking me a while to pull out all my soldering stuff & get down to fitting it together - gonna sweat the chamber right now & then fit together to check for leaks (and make sure my trigger assy. works). the regulator is a Palmers Stabilizer . uit was free! no kidding a local paintba...

The combustion gun I am working on (should be completed sometime in January) will have a 10ft long chamber, and a 15 gap spark strip powered by a photoflash circuit and 2 ignition coils wired in anti-parallel. It will also be hand held, capable of 500fps with a 1lb projectile, and capable of reload...