SpudFiles

I like the way you think.
Though that doesn't really require an adjustable regulator (just one you can set to the right pressures and that's it (thought it's worth clarifying this to avoid confusion*)). Just two valves - one for fuel one for air. You could go ahead and add a third one to control an air cylinder that loads ammo and provides force necessary to seal the chamber. This can probably be handled by just two valves using some clever design, but for the first working prototype you'd probably want something as basic as possible.

*Though technically with fast enough valves and a pressure sensor you could get away with two valves only. Essentially controlling pressure by opening and closing valves until the require pressure for both fuel and fuel&air mix is achieved

POLAND_SPUD wrote:I like the way you think.
Though that doesn't really require an adjustable regulator (just one you can set to the right pressures and that's it (thought it's worth clarifying this to avoid confusion*)). Just two valves - one for fuel one for air. You could go ahead and add a third one to control an air cylinder that loads ammo and provides force necessary to seal the chamber. This can probably be handled by just two valves using some clever design, but for the first working prototype you'd probably want something as basic as possible.

*Though technically with fast enough valves and a pressure sensor you could get away with two valves only. Essentially controlling pressure by opening and closing valves until the require pressure for both fuel and fuel&air mix is achieved

Definately. I was actually going to try and do what you're describing as my senior project for my degree - however I couldn't get enough like-minded students together to work on a super gun haha... go figure I did end up getting one of my projects approved and did it for our senior project (we had one of the largest groups too!) though...

But either way - I'd like to work on the concept a little more now. After I'm done with this dammed 3D printer project I'm working on I'll try and get back to spudding projects lol.

Pass me a beer!

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Ball valve pneumatic at 2:15

jackssmirkingrevenge wrote:Love the hinged barrel! Is there some kind of seal involved or let the gasses escape where they may?

Late, but yes, there's an o-ring around the port. It leaks but it's almost unnoticeable.

My neighbor fired this thing at full power in the garage the other day. I like the quote he gave-
"When I shot it... everything moved."

Did the earth move for thee?

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Cops are now using pneumatics. Nice idea to have a "sticky" projectile instead of a potentially dangerous dart.

Cops are now using pneumatics. Nice idea to have a "sticky" projectile instead of a potentially dangerous dart.

They have a lot of work to do... At 30+ MPH, I really don't see the tracker sticking at all.

ITWOSY, after a very long delay spent learning more than I ever wanted to know about equations of state, I finally have a working 1-D model of a gas gun. It isn't very feature-rich or easy to use right now, but it accurately replicates analytic results for shock tubes and piston-cylinder arrangements. There's still some tweaking to do and features to add, but it should be available to the general Spudfiles community in a month or two for modelling of inline single or multi-stage guns.

If anyone has an interesting problem they want modelled RIGHT AWAY and can't wait for me to release the code, just PM me.



Sample v(x) plot for a gun with a relatively lightweight projectile and a dead volume equal to the chamber volume.

ITWOST... I can only build things in fantasy-land at the moment.

In other news, raytracing with transparencies takes forever on a laptop... even a laptop with an i5, lol.

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Would this stuff be benificial for hybrids to use as a chamber lining? I could see it reducing heat loss to the chamber walls, thus increasing chamber pressure. I'm not sure how well it would stand the pressure though..

Hey y'all, quick question... I'm trying to do a research paper on piston valves, so I am looking for the first one ever made on the forums. Anybody know who was the first? I seem to recall is was clide on spudtech but I can't find anything about it... any help would be appreciated!

I'd check the SpudTech archives if they're available.

Wasn't it the mythical "supah valve"? In any case the exhaust valve concept has been around for much longer.

jackssmirkingrevenge wrote:Wasn't it the mythical "supah valve"? In any case the exhaust valve concept has been around for much longer.

Hmmm, didn't think the supah valve was the first one. I figured this type of valve had been around for very long (similar patents are around from the mid 1900s) but I was more aiming for the use of homemade piston valves in spudding.

It might be a chicken/egg scenario - but my gut feeling is that the Antenna Launching folk came up with the valve's spud gun usage first.

It's certainly not a novel idea with origins in spudding, but it was a major game changer with regards to spudding's power output and effectiveness!

For some reason I just remember an antenna launching website in early 90's framed format that had a pretty good documentation on the build/design and low resolution 90's digital camera pictures to boot haha.

Good luck in your search none the less - it will be interesting to see a well documented history formulate of this hobby - Paintball has similar nostalgia to me and is documented really well with regards to the tech inside the markers.