any clue on how the cartridges on the defensive pistol work?

Thanks for the suggestions folks I ended up buying a section of metric PVC here

MECCANIXITY PVC Rigid Round Pipe 45.2mm ID 50mm OD 350mm Light Grey High Impact for Water Pipe,Crafts,Cable Sleeve https://www.amazon.com/dp/B09J14XH93/ref=cm_sw_r_apan_glt_fabc_6N8GEHY78V6YNQNN7PKY?_encoding=UTF8&psc ...

I haven't accounted for friction that would require more information than I have access too. It would just involve adding a friction component to the equilibrium a freeze frame in time, one when it's fully open one when it's closed but it also involves an arbitrary increase in spring compression ...

sorry I'm very late to provide any useful contribution, Statics class is a long time ago did a slightly different force analysis on your original regulator design and got basically the same force formula just phrased F0=(pi/4)*(p1(d1-d2)+p2d2) if that any reassurance
also the pressures involved ...

good news while it was fun to refresh my trigonometry and kinematic equations I found a projectile calculator online
as soon as you enter an initial height time in flight and angle you should get a result https://www.omnicalculator.com/physics/projectile-motion
based on your 16seconds at 45 degrees ...

I was testing some ping pong balls with a 1.5" PVC drain tee and discovered it had the perfect geometry to facilitate shooting a single ping pong ball at a time.
In other words I found a tee that will work as a gravity fed hopper for a semi auto ping pong cannon.

The problem is I need a loose ...

I stopped by my friend's place made a simple test shooting shuttlecocks made from bottles at 60psi vertically

Hey guys just a product heads up for a high voltage spark source.
These days I notice Amazon won't ship cheap stunguns to areas even adjacent to areas with stungun restrictions, but I got mine under $6 this is cheaper, they go by a lot of names but look the same. It work's great will runs on an ...

You mention non-lethal are these gentle enough for say mil-sim or surprise gender-reveal parties

Very impressive technology, what kind of application do you have in mind for these?

Good to see more of your fine work, last time I saw your work was a video with jamie hyneman. Are you yourself active on any other platforms?

I see what you mean requiring positive pressure to open prevents the valve from opening every time you disconnect the air source, just need to machine more air seals.

That's an interesting use of an air cylinder, but you really have the same effect from a QEV or a more common homemade piston valve. And as long as the air cylinder internal diameter is greater than the barrel diameter it should work fine.

But I don't really see an advantage to using an air ...

Could you make something like a thick 1"+ diameter threaded rod longer than it needs to be, then the end user can saw it to length. I think spacing as low as 1" makes sense, for barrels 1.5" PVC and 2" PVC, chambers 3" and 4"

Oh wow that's very different from what I guessed.
It looks like a regular pneumatic cannon but it lets water in the barrel, it seems like they even aim it up to prevent the water from spilling out between shots.

Besides making a fast opening cannon, put something on the muzzle to help create a ...