creative block

Moonbogg · Thu May 28, 2009 2:34 am

There can't be any compressed air supply. A compressed air supply would have to be replaced, refilled etc etc. The ideal way (for me anyhow) is to have the cannon operate just as freely as any advanced combustion. When the mapp or propane & o2 tanks empty, you simply replace them for about 8 bucks each, but that will take a long time.
The trick is having no remaining chamber pressure because that will take away from some of your preignition pressure capability and place useless pressure on your bursting mechanism.
The bursting mecahanism must be of adequate force to provide a powerful combustion, it must resist 100% until it blows and when it blows it must do so without any resistance behind it, maximizing flow, just like a real burst disc would. Then it must be able to be reseated effortlessly for another quick shot. No c&c none of that expensive crap allowed. Anyone must be able to make one with a little patience at a decent cost. This is my challenge.

http://www.zdspb.com/media/tech/animati ... rt_man.gif

might be an inspiration for a piston design of some sort.

inonickname · Thu May 28, 2009 3:36 am

I challenge you to beat me

If you can go smaller, I'll be impressed. I'm up for competition.

Ragnarok · Thu May 28, 2009 3:51 am

Moonbogg wrote:When the mapp or propane & o2 tanks empty, you simply replace them for about 8 bucks each, but that will take a long time.

So what's wrong with an HPA bottle?

Not that you've got to have an oxidiser supply at all, but it's an easy way to go about it.

inonickname · Thu May 28, 2009 6:29 am

wiki wrote:Ablation pressure:

* Ivy Mike: 5.3 billion bar (530 TPa)
* W-80: 64 billion bar (6.4 PPa)

If you fueled a spudgun with nuclear fusion/fission the power is rather high. From a working pressure of 64 billion bar at such high temperatures a sub 1 grain projectile has enough energy to kill you..more than once. (a lot more)

Though jokes aside, I believe small is the way to go. How about a miniature combustion cannon that works like the tippy c3?

Moonbogg · Thu May 28, 2009 9:11 am

inonickname wrote:I challenge you to beat me

If you can go smaller, I'll be impressed. I'm up for competition.

Holy crap, you have a fan in it. Thats impressive I totally agree. Don't make me go to a swiss machine shop =) jk

Moonbogg · Thu May 28, 2009 9:23 am

Ragnarok wrote:
Moonbogg wrote:When the mapp or propane & o2 tanks empty, you simply replace them for about 8 bucks each, but that will take a long time.
So what's wrong with an HPA bottle?

Not that you've got to have an oxidiser supply at all, but it's an easy way to go about it.

Well I just tried to find out how to fill a $50.00 HPA bottle to no avail. Any idea on how you refill these things? How many times can you fill a decently large hybrid chamber for a 4X shot with these things? It doesn't look good to me.

EDIT: Oh yeah, whats the secret behind your oxygen-less hybrid design?

OOPS...how do I delete a post!

Ragnarok · Thu May 28, 2009 1:05 pm

Moonbogg wrote:Well I just tried to find out how to fill a $50.00 HPA bottle to no avail. Any idea on how you refill these things? How many times can you fill a decently large hybrid chamber for a 4X shot with these things? It doesn't look good to me.

Usually airgunners get them filled at sub-aqua shops. And your second point has so much missing information it's beyond answering. Tank pressure, Tank size, what you consider a decently large hybrid chamber, whether or not you're purging with the air in the tank or not.

Oh yeah, what's the secret behind your oxygen-less hybrid design?

Which one?
The compact 2x limit one, or the larger, more complex 10x limit one?

OOPS...how do I delete a post!

Double posts happen at times - there's no way of deleting them unless you're site staff. Don't worry about it.

Moonbogg · Thu May 28, 2009 3:07 pm

About the HPA thing, I think it would be a pain for many people to be dependent on a scuba shop in order for them to use their cannon. I read a paint ball post where an HPA user's local air shop moved and now hes screwed lol. I guess you could use a $200.00 PCP airgun pump. I read that HPA doesn't give nearly as many shots as CO2 does. With a cannon like the Venom for instance, lets assume it is a contained gun with MAPP and HPA operating at 2-3X. I don't think that any reasonably sized HPA tank would be able to provide many chamber fills, especially if you do a quick spray between shots for a quick purge. HPA tanks are also pretty expensive from what I have seen, even the smaller ones. For the price of one small tank you could buy at least 5 oxygen cylinders. If there was an easy way to fill it then I would agree that it would work well, but you'd still be tethered to a pump or something.
About the oxy less hybrid, I was wondering about the basic principle. Lets go for the simple one for the sake of conversation. I imagined a pushrod piston thing with a handle that you could push into the chamber to compress air for each shot, but if the chamber is too large it will be really hard. Anyway, how does it work? Go ahead and spill on the 10x one if you are willing. It has my interest.

Ragnarok · Thu May 28, 2009 5:26 pm

Well, the 10x one is just a redesign of a standard 4 stroke engine design that's able to cycle reliably one ignition at a time. Actually, I'm surprised the idea hasn't come up before, because it's actually insanely simple.

It would work well as a semi automatic, and indeed, it would be possible to modify the design so that it would be able to drive a full-auto gatling loader, perhaps at up to BBMG rates of fire.

The other idea is basically a two stroke engine - with the exception that it uses a valve system I designed a while back, and again, it's able to cycle an ignition at a time.

Like I said, there's nothing all that complex about them. Still, either design is going to be relatively bulky as a result of how you'd need to achieve the pre-compression, but they'd work well for small chamber or low mix hybrids. Large chamber and high mix wouldn't be a good combination for them.

Mike_Hunt0420 · Thu May 28, 2009 6:32 pm

I think i'll try my hand at a full auto mini and at this hybrid being discussed. I can try to mix o2 and propane in a single tank so the fuel won't need to be mixed though it'll take some work to make sure I don't just make a bomb out of my cannon lol

Technician1002 · Thu May 28, 2009 7:15 pm

Mike_Hunt0420 wrote:I think i'll try my hand at a full auto mini and at this hybrid being discussed. I can try to mix o2 and propane in a single tank so the fuel won't need to be mixed though it'll take some work to make sure I don't just make a bomb out of my cannon lol

It may be worth working on a mix on delivery. It would consist of a couple adjustable flow valves with a pair quick of shut off valves.

It would work mixing and delivering gas on demand like the commercial rodent blaster product. I won't post a link to the product to avoid a thread lock.. That product is against forum rules.

Moderator, the mention was just for a gas mix suggestion.. not pest control.

Mike_Hunt0420 · Thu May 28, 2009 8:41 pm

This should be quite the project lol, maybe something like this: http://www.spudfiles.com/forums/handhel ... t9931.html but swap the quick connect for the compresser for regulated o2? I'll have to mull it over for a bit, maybe make a bbmg while I'm thinking, those things look like aweful fun.

Mike_Hunt0420 · Thu May 28, 2009 8:45 pm

inonickname wrote:I challenge you to beat me

If you can go smaller, I'll be impressed. I'm up for competition.

I might be up for that, a few questions first. What kind of power you looking at on that little guy? And I might be inclined to make one smaller just to try it but really, are they even worth it that tiny? No offence I still think mini's rock but I just have big doubts as to their power is all...

Moonbogg · Thu May 28, 2009 9:38 pm

I'll stick to the hybrid for now, then maybe tackle the mini.

jook13 · Thu May 28, 2009 10:36 pm

And I might be inclined to make one smaller just to try it but really, are they even worth it that tiny? No offence I still think mini's rock but I just have big doubts as to their power is all...

Well, I got 230 feet per second with this little thing:
http://www.spudfiles.com/forums/300-win ... 17408.html

That is about 40 fps faster than my red ryder bb gun. Of course I was using 400 psi of air.

If it is power you want then I doubt a mini combustion is the way you want to go.

If money is no option and you want a challenge, I say go for a large bore pnuematic with high pressure. I could only imagine a steel cannon with a 4 inch barrel and 500 psi. It would be more awesome then a one legged waitress working at the IHOP.