Hi. wondering if this design would work. Little hybrid

[Rob748]

Can you tell me how to build the propane injection system ?

[starman]

First off, do some homework on hybrid construction. Here's a Wiki that can get you started.

A burst disk literally seals the breach allowing the chamber to hold a pressurized fuel/air mixture. It is significantly weaker than the chamber material though and will burst, like a balloon, when the fuel air mixture is ignited. This hold back of pressure acts as a very fast acting valve and presents the projectlile with maximum power as early in its barrel travel as possible.

Burst disks are typically made of an iron union and several layers of aluminum foil, the number depends on the area of the breach opening and the desired pressure at which you want it to burst.

I have implemented a simpler burst disk with camlocks and 3M 2" masking tape as shown here.



I'm presently using this very successfully on the Trip Thunder 1x advanced combustions.

[Rob748]

and trigun my friends dont have a burst disk. The marble with ducktape wrapped around it (projectile) makes a good enough seal to hold up to 5 psi. Its pretty mucha normal combustion cannon with a bicycle tire valve in the cap and you use a bicycle pump to air it to 5 -10 psi. Then hit the ignitor. if you dont belive me that this works thats fine. All we do is spary like 3 seconds of right guard into a 3 inch pvc and pump 5-10 psi in it. And it go boom

[trigun]

Believe me I'm not one to go it wont work I'm just saying your method isnt 90% accurate. So when you say 5 psi it is more luck a tight fitting projectile then a burst disk which is required on real hybrids.

Darn you starman beat me to your own picture

[starman]

Can you tell me how to build the propane injection system ?

No, you're not studying my man. This information exists in many places...primarily http://www.burntlatke.com.

Here's fuel metering and burst disking in action....

[youtube][/youtube]

[Rob748]

Is that a hybrid ?


or a advanced spudgun ?

[trigun]

That is an advanced combustion

[tape fist]

Its an advanced combustion that uses a burst disk .

[starman]

Is that a hybrid ?


or a advanced spudgun ?

It's built like a hybrid but with sched 40 pvc. I have tested it as a 1.5x hybrid, it worked great, but I don't operate with anything but a 1x mix when handheld....meaning all of the time.

I use it as a burst disked 1x advanced combustion...originally primarily designed as a noise cannon.

[trigun]

http://www.spudfiles.com/forums/icon-ne ... 17357.html
http://www.spudfiles.com/forums/the-hyb ... t9879.html

those are hybrids

[Rob748]

So you can have a burst disk on a metered combustion cannon ? Could I build a propane metered cannon that used schedule 40 ? the combustion chamber would be 4 inches by 34 in. and the barrel would be 4 ft long ?. If I used a burst disk and a propane metered injection would it have significant more power than a normal combustion cannon ?.

How much would the costs be ? where and how much does a burst disck cost ?


Thanks i really want to build a smaller replica of that one. il ldraw something very detailed and post it here in a couple of minutes

[trigun]

Wow now your starting to think ...http://www.spudfiles.com/forums/herminator-t17209.html
this is my gun it has similiar dimensions but your barrel is roughly 10+ feet to short for optimum performance

Really loud and will easily blow a hole in plywood.
Cost me ~ $40

[jmeyer1022]

Yes, a burst disk will help a lot of a combustion cannon. You can use schedule 40 PVC pipe for it. I'd suggest a smaller chamber that is a large chamber. It would have a lot more power than your average spray and pray.. I mean a lot. Cost wise, I've heard different prices but look the video I linked earlier said his was about 150$ and it is very well done.
Also this link will help you find a good C:B ratio. I believe you want from .85 to 1.5, .85 being the best, not positive I'd wait for someone else to confirm this first.

http://members.tripod.com/potatogunwarr ... online.htm

[starman]

So you can have a burst disk on a metered combustion cannon ? Could I build a propane metered cannon that used schedule 40 ? the combustion chamber would be 4 inches by 34 in. and the barrel would be 4 ft long ?. If I used a burst disk and a propane metered injection would it have significant more power than a normal combustion cannon ?.

How much would the costs be ? where and how much does a burst disck cost ?

*palmface desk combo*

Sorry you're going to have to engineer all of that on your own. We don't spoon feed all of this information to you. All the information you need is at your finger tips...you need to study and find it. YOU need to have a good comprehension of what you're doing before you go down this trail...especially in the case of a hybrid. It's for your own safety.

Get started with HDGT, gun modeling program. Saves you a lot of time and helps you understand what you're doing.

[jmeyer1022]

I'm done posting here until I see that you've put a serious effort into building this.