So when do we get to see the unbalanced spool valve that opens with the anemic 19th century hammer at 3 kPSI? I see you have mastered clairvoyance :D Seriously I can easily replace the CO2 bottle with a 3000 psi tank and making a balanced valve would not be that much of a challenge... I'm just worr...

hectmarr wrote: ↑

Fri Feb 26, 2021 9:41 am

I think I would like to have something like that, to play with.

As long as you do it safely

I gave the balanced valve a go and was able to raise firing pressure to 1100 psi. Some initial testing: https://youtu.be/FnSsZp7-18M Best velocity recorded was 774 fps for 59.3 ft lbs, around 50% more than the maximum for the conventional valve. I was a little conservative with the diameter of the b...

Some balanced valve development: https://i.imgur.com/hRYtNSph.jpg Balanced valve V1 and housing compared to the improved poppet and original housing. Note the groove at the head of the valve to allow air to vent into the balanced portion. The head diameter is also reduced to 6mm from 8mm for better ...

Nice! It's going to be great seeing it in action with the alternating barrels, especially if the rate of fire is low enough to be able to perceive it.

Good improvement! More than 900 fps with that lead ball? steel? You can see the ammunition here , 0.310" diameter lead balls that weigh about 2.9 grams. The debated but still quite valid rule of thumb for the minimum energy required for a kinetic projectile to reliably produce a potentially lethal ...

I got a serious engineering job out of school and that's moved me into an apartment and diverted my attention towards some more electronic/computer projects Been there... it will get better! I like the idea of a captive piston with some serious venting at the front of the barrel. I'm imagining the ...

More balanced valve development: https://i.imgur.com/jh1PIxrh.jpg Version 2.1 with a stronger spring and a shoulder that bottoms out before the base of the valve hits the end of the balance chamber. At 1100 psi, again using 45 grain 0.310" lead balls, the chrono read 789 fps for 62.2 ft lbs. At 1500...

Those numbers are looking pretty crazy! We're definitely in modern big bore airgun territory :) It turns out there's a book that looks at these devices in detail, "Construction and Operation of the Air Gun Volume 2 - The Walking Stick Air Gun" The performance listed for a similar muzzle-loading air...

Really getting into the Nerf stuff and transformed my airsoft bullpup into a single shot muzzle load pistol by turning the grip and trigger around, barrel is a piece of 1" round nylon that I drilled to take the Nerf dart, these are actually X shot darts which work much better as they have like a rai...

That's what I mean when I say that mechanics always teach me something, when I do tests, and I think that most of the time, first there is the fact and then the law My style of engineering tends to be... "optimistic" ... so it usually takes a few tries before I do it properly, the way I ought to ha...

hectmarr wrote: ↑

Fri Mar 05, 2021 10:05 am

As my dad used to say, new wine in old jars.

A true poet, I like this expression

It is impossible to stop thinking about what the captive piston can suck, due to its inertia mass, from the back, after expelling the projectile, perhaps a measure of combustible gas. 8-) I had no idea about this kind of technique, it seems simple to me and it works very well. With the same combina...

An idle thought that is basically the unholy marriage of a nailgun and paintball marker: https://i.imgur.com/LqY0rAO.gif The benefit is that it will fire whatever fits in the barrel and it doesn't need to be airtight, indeed it could be fed though a hopper of shot of whatever size doesn't fall thoug...

"if it only fires one shot I am not interested"

Classic Hector

I think we had started down that road here...