You need something to induce turbulence! Some experimentation was definitely in order, so I machined a Delrin cup to fit the chamber with a 1/4" orifice through the base: 20231206_213324.jpg baffling.png I fired a series of shots and the results were quite interesting. The first thing I did was rep...

pressurepiling.png Looking at this in more detail, the paper describes what is happening in a closed system, with a significant pressure peak happening in the secondary chamber much higher than what occurs in the first one. In our case the dynamic is a little different as we want the second chamber...

I made a second baffle that was both shorter and with a 1/8" orifice that looks something like this to scale: baffling2.png I then did some more testing again at 16x and using photo paper disks and 0.25g airsoft BBs as projectiles: 1) 1 disk no baffle - 1136 fps / 21 J 2) 1 disk baffle - 1851 fps / ...

If my gut is right, making the baffle shorter (increasing volume of the chamber that has the spark gap in it), will decrease performance (decrease the step function effect). According to the study that inspired hectmarr's other thread, peak pressure should increase, but for a smaller effective volu...

While using a single o-ring as both a seat seal and a check valve for filling functioned as a concept, I noticed that sometimes while purging the air line it would not reseal immediately, resulting in lower pressure in the cartridge and inconsistent performance, so I've modified the design with a se...

Thank you gents! I love all the effort to keep it looking stock and completely reversable if desiring to use a conventional flare. It also means that the cartridge can be used in any 26.5mm flare gun, I'm really tempted to make a 12 gauge version. I log back into this site every month to see what's ...

An interesting BBMG project with the pressure ramped up and correspondingly impressive rate of fire:

Here are some details of the valve, first with o-ring in place and then slide down to show the groove: http://i.imgur.com/Zx2I8Hyh.jpg http://i.imgur.com/17IwsIWh.jpg Also interesting to note the about of wear happening the two areas where the locking balls contact, on the firing pin as well as the ...

Welcome to the forum! It's a little hard to picture your project without images, and can you link to the valve you intend to use? To my knowledge the "Z" type valves are intended for AirForce Talon/Condor type rifles that have a hammer coaxial with the barrel. If the dimensions you described are wal...

Some design studies for a 12 gauge air cartridge

Ok ChatGPT are there any real people left on the internet?

AndyWood wrote: ↑

Fri Dec 29, 2023 6:56 am

I agree with you.

Ironic.

Excellent work as always, as I've said privately the fact that you've made it work consistently would be admirable even if looked like a bunch of random parts thrown together, but you've also managed to make it neat and stylish, kudos! The trigger guard integrated in the pump handle is really a nice...

iggy1328 wrote: ↑

Sat Jan 13, 2024 12:23 am

Got a bit too drunk last night, woke up this morning with a new cannon.

I hate it when that happens

I've heard of posting under the influence but this is something else!

With those material specifications it's a shame not to go a little hybrid, even a low mix would be impressive.

I had an account here in 2013, and had so many builds to try out but no money. Now I'm financially stable but I lack innovation lol. A tale as old as time :D Have a look through the forum, there has been quite a bit of innovation in the hybrid department especially. I've mostly been bringing older ...