SpudFiles

Hubb wrote:If the cartridges are to stick around, why not make them fire like real cartridges? Instead of lining up wires and spark gaps and all that stuff in each one, why not use a bullet primer with a firing pin to set it off

That begins to blur the line between spudguns and firearms. Also, when your trigger is a switch you're free to put it anywhere unlike if it was a lever releasing a hammer, so there are advantages to an electric setup.

Okay all you voters out there, before this thread goes to sleep, which would be a real shame, what's to be done with the community project?

Preloaded 'cartrouches' seem to have been passed in.
...Which is fair enough since I think even I could make a single shot bolt action (...now that I have access to a lathe... ) so it's sort of under-utilising the talent that should be available should the forces of spud-goodness flitting around here combine!

How about a wankel-rotary style gatling gun?

I'm pretty taken by al-xg's Auto air rifle!

Comments?

Suggestions?

I would like to make an experimental cartridge - even for my own purposes - where there is no burst disk but only the projectile jammed inside a flexible tube of some description, that would be able to contain the mix pressure but not that of combustion. A schrader would be added to the back for pressurisation. I think this would be the simplest idea for quick relatively simple manufacture and loading.

Incorporating al-xg's gas piston reloading is also a possibility, though it would be substantially more complex than direct blowback, particularly if a locked breech is to be incorporated.

I like the idea and have thought of similar things myself, such as having a PTFE o-ring hold back a gold ball until the cannon is fired. It would limit the types of ammo that could be used, but the benefits could be great.

Moonbogg wrote:having a PTFE o-ring hold back a gold ball until the cannon is fired.

I don't think the community project budget is that high maybe we could use golf balls instead

Seriously though, wouldn't the dimples on a golf ball cause sealing issues?

If we want to use a "real" firing system on cartridges why not a cheap cap (paper or plastic). I don't think that we would be pushing it too far on that, and BtB even used a flintlock cap (I think?) and later changed it to a cap.

I would vote for keeping things electric, this removes the need for a hammer mechanism which would then have to be linked to the trigger and also reset by the action if semi/auto fire will be an option.

Whats wrong with gold balls? Are you guys hard core or not?

Moonbogg wrote:Are you guys hard core or not?

To hell with it, Rhodium ammo!

Solenoid? Reciprocating cam? Neither are difficult to integrate.

Another consideration for cartridges would be a steel wool fuse (or nitinol/nichrome)- they only require a short blast from a 9v battery and they will ignite flawlessly if the mix is right. Clicking a piezo every single shot will be repetitive, slow and cause blisters. Pressing a small microswitch is easy.

How do you guys like the website? Is it cool so far, or is it weak and gay?

Well then. A cartridge it is. I like the idea of a non-burst disk cartridge as well as the nichrome wire firing mech (which should simplify matters as long as nicrhome wire is available).

As far as loading them, a simple break barrel would work. Something like Moonbogg's contest entry would probably be ideal. This would cut down weight and still meet qualifications for the project. Besides, in this manner, the cartridges can be strapped to your chest in a bandolier.

Steel wool will work as well as nichrome I believe, though nichrome would be more professional and maybe slightly more reliable.

Nichrome can be found in heating elements (for example, old hairdryers) or purchased online. It's normally used in staging/igniting pyrotechnics. I know from experience that BP meal is MUCH harder to ignite than propane/mapp/butane and air/oxygen. So I believe the ignition would be extremely reliable.

Moonbogg wrote:How do you guys like the website? Is it cool so far, or is it weak and gay?

Looking good, but perhaps it should have its own thread?

Nichrome can be found in heating elements (for example, old hairdryers) or purchased online.

That's where I get mine Well it would certainly simplify the trigger mechanism, battery and switch

As far as loading them, a simple break barrel would work

So we're making an M79 then?

Surely if we're doing cartridges something a bit more... cartridgey is appropriate

Not necessarily an M79 variant. I was thinking more along the lines of making it easier to hold and carry. What would be nice is if it were to have, say, 6 rotating chambers that would spin either through some sort of firing process (like the Eclipse) or a pump action.

Actually, the rotating chambers is probably not a bad idea, especially if each cartridge houses its own ammo and fuel as mentioned above. The launcher would then basically consist of a triggering mechanism, handles for holding, and a barrel.

As far as nichrome wire is concerned, I've taken them out of hair dryer,s toasters, and those small little space heaters. It can also be purchases at a few places. Steel wool could be an alternative, but that gets a bit more finicky compared to nichrome wire.