SpudFiles

it is much better to make the drummer cock up with air that leaves the pilot valve. That works too and is especially useful if one were making a big-bore repeater where too much air would be wasted cocking a direct hammer valve. I have animated it to explain the concept: https://i.imgur.com/cEQ1yC9...

farcticox1 wrote: ↑

Mon May 18, 2020 5:48 pm

127mm or 12.7mm

Good catch, edited.

That is the pop-off valve that actuates the QEV. I had done something similar with a commercial pop-off valve: https://youtu.be/nkibwn6wEns The movement of the pop-off pistol is brief and abrupt, I do not think you could get it to operate a blowback mechanism. It would make more sense to harness the...

mark.f wrote: ↑

Thu May 14, 2020 8:09 am

something like a PTR-91 although I'm certainly no expert on Canada's firearms laws and it may have already been restricted/prohibited.

Already prohibited:

The firearm of the design commonly known as the G3 rifle, and any variant or modified version of it

Maybe a Kel Tec SU-16 or RDB...

I pondered a Fly-K style type spigot mortar a while back...

edit: damn, that was almost 10 years ago. Time's a wastin'

I think JSR just had an aneurysm. :mrgreen: Almost... The reason why even though I make the effort to maintain my status as an eligible bachelor, I have no intention of renouncing on that bachelorhood. This lockdown has been quite insane, it turns out that when people are stuck at home they buy toy...

It would sure be fun to move a spuddy in a "buyback" as a firearm that exceeds safe civilian use. You could turn out simple combustions by the dozen and turn a good profit :D These new restrictions are so arbitrary and overreaching that they will hopefully tread on enough toes to generate a meaning...

You must think in terms of cross-sectional area. In this case, 75mm is almost 6 times greater than 12.7mm, but in terms of area it is a whopping 35 times greater. This is not a recipe for good performance. The effects of the Square-cube law are quite pervasive in this hobby. Finding a bigger valve c...

What exactly do you mean by "blowback action"? Do you want the QEV to also operate a self-loading mechanism?

This outbreak really is bringing people back online :D a lot of force needed to compress it though It would probably look like a ratchet mechanism on an ancient ballista. Doubtless an interesting project but on this scale pneumatics are so much more practical in terms of using off-the-shelf materials.

It took a gosh darn global pandemic to get him back here :roll: :D how many days of quarantine is it? Don't remember the last time I signed into the files and made a post. Who calls this place "the files"? https://i.imgur.com/BYyr2vw.gif :D Last year I got a call from SpaceX, and made the decision t...

Welcome to the forum! You can find them here, for a combustion spud gun you want HGDT:

viewtopic.php?p=387228#p387228

Very cool project! We have these at the shop and were just discussing how it would be the basis for something a bit more hardcore :D I guess the valve looks a bit like the one on airsoft revolvers? https://i.imgur.com/wYllAqL.jpg If so you might want to look into the possibility of opening up the fl...

Welcome from the land of the lurkers! But now here comes my question, because my chamber is 30ml there is only ~0,6ml of atmospheric air in the chamber left, far off of stoichiometric ratio. So should I pump 20 BAR insted of 19 to get right ratio, or am I missing something here? That's an interestin...

Gippeto wrote: ↑

Tue Mar 17, 2020 9:37 am

Debby Dunning had it going on

Arguably still does, for someone past the half century mark.