compressed air lung... with theory for gatling gun

[trollhameran]

Definitely going to build this one, i've always wanted to make a gatling gun but every time i think of a design it is flawed beyond belief.

I have thought of a way to load the projectiles, ill try and draw a diagram of it and then ill post it up.

[jackssmirkingrevenge]

Now how to load the projectiles?

That's not too hard to thing up - sleeves over the slots in the barrel, that are opened by a circular ramp as barrels spin - a bit how the bolts are reloaded on Richard Gatling's powder burning original

[youtube][/youtube]

I had proposed this concept back on spudtech over two years ago - the theory works, as to the practice, it gets a bit complicated...

[trollhameran]

the yellow blobs are the ammo, the thick black is the shells which are connected by fishing line, read my first post about the gatling gun to understand, the thin black lines are the barrels and the thin black lines sticking out of the barrels are the pegs which are used to catch the shells into the barrels as they go around

[jackssmirkingrevenge]

Why not just feed round projectiles from a hopper, much simpler and therefore much more reliable

[trollhameran]

Yeah that would be easier, i'll probably end up doing that simply because its going to be hard enough just getting the timing of everything to be perfect and for it all to run smoothly

[jackssmirkingrevenge]

I would suggest buying a relatively cheap CO₂ motor such as the Gasparin G-28as a starting point, it will save you a lot of time and engineering and being made for CO₂, will probably provide a better gas impulse to fire the BBs.

That said, for worthwhile performance you might need to engineer a custom device with a large enough valve to provide a worthwhile propelling burst.

[trollhameran]

I may do that if i can find a nice cheap one to work with or i was thinking of using the casing and piston from a reasonable size hand pump and using the pump part as the arm which the crank will connect to, then all i need to do is make a suitable way of blocking the air intake the other end of the pump, like the ball does in the diagrams and also i would need to get the crank to turn a wheel properly, apart from that i cant see any problems with making it out of a pump casing.

[Acdcmonkey1991]

I've been bulding an engine on this principal for weeks... anyway, the air hogs run the same way

[trollhameran]

what are you building your engine out of? what size is it going to be?

started putting the engine parts together today, not sure if the way i have set it up will work or not yet but i can always change it and make it work

[jackssmirkingrevenge]

The important thing is to build in adjustability so you have some leeway for tuning, usually a better idea than scrapping everything and starting over.

[psycix]

Awesome video JSR.I have searched for such information and I always wondered if any good videos like that one were around.

Make the gun as adjustable as possible, you indeed will need to tune and tweak it alot before it works properly.

[trollhameran]

Yeah i realize it is going to need alot of tuning to get it to work so I will be using compression fittings wherever possible and any parts that arent pipes will be fitted together either with bolts or screws so that it can easily be taken apart and modified

[trollhameran]

I have just taken pics of my prototype for the piston part

This is it taken apart the bit on the left is the piston out of a bike pump with some springs on it and a crank arm, the long bit of grey pipe with the marble on the end is the rod which allows air to flow in when pushed up by the piston and stops air flow when the piston is down and the chamber is full, i have drilled a hole in the casing just above the bottom most point the piston reaches when fully down, and the marble will be housed in a check valve to keep it at the top of the chamber and to allow air to flow past it when it is pushed up slightly by the rod.



This is it put together, tomorrow I will connect it to the compressor and test it, cant tonight because its late and dark.

[Acdcmonkey1991]

The piston housing is 1.5 in. and the piston is 3.4 in. the valve is a 1.5 in. check valve, I still need to make the crankshaft though...

[trollhameran]

ah cool, your is quite a bit bigger than the one im making then, but i will probably make a bigger version once i get it to work. Im planning on making a smaller bb version of this gun to test it and get rid of any flaws in the design before i make a bigger version with higher caliber, as I can make a bb one alot cheaper to start with