Hybrid Question

[Spudgunner86]

How do Hydbrid cannons work, Is it burst disk technology or is it a different tech? please elaborate.

[boogieman]

In a nutshell:

The basics to understanding fuel:
Propane will only combust when its within it's flamability limits. Propane will burn within about 2% - 8(9?)% concentrations. Any higher or lower, and it will not combust. The reason behind this is that you need fuel, oxygen, and a ignition source to get combustion. With too high of a concentration of fuel, you do not have enough oxygen to ignite. (Oxygen refers to natural oxygen that we breath, not the bottled kind. Bottled oxygen should not be attempted with plastic spudguns)

So... You could make a spark inside of a chamber pressurized to 100psi with propane, and it wouldnt ignite. A 4% mix has been tested to be the "ideal", meaning most powerful, mixture. What this means is that if you have a 100 cubic inches at atmospheric pressure, you will need 4 cubic inches of propane at atmospheric pressure.

Fuel meters let you measure this 4% out reliably each time. This 4% is refered to as a 1x mix. If you need some basics on how fuel meters work, look on www.burntlatke.com for more info.

Now then, what hybrids do is allow you to combust more propane. After reading the above, you should realize that this is not possible in and of itself. Say you have a 12% fuel mix. (this would be considered a 3x mix(12%/4%=3)) It wont light.

Now then, to light the 3x mix, you need more oxygen. To get more oxygen you must add more air. The purpose of the burst disk is to hold this extra air in the chamber. You have a 3x fuel mix in the chamber, so you must also have 3 atmosheres of oxygen to combust it. Atmospheric pressure is ~14.7psi. So, you have one atmosphere in the chamber now, so you need to add 2 more, meaning, you will pressureize the chamber to 29.4psi (14.7 x 2).

Now you have your fuel and oxygen, all you need is a spark. Use your ignition, and BOOOOOOMMMM!!!! The rapidly expanding gasses blow the burst disk out, and the ammo is launched.

Hybrids are much more powerful than any other type of spudgun. The pressurized fuel has a MUCH faster rate of burn, and produces much more pressure. To top this off, a hybrid using the 3x3atm mix will have the extra 29.4psi pushing the projectile. This would be similar to the power of a pneumatic shooting at 29.4psi. The extra pressure is just gravy .

Hope this helps

[Spudgunner86]

Ok thanks boogie
;D

[boogieman]

No problem

[aetherguy881]

What are most burst disks made out of?

[Lukas]

I've heard of aluminum foil (several layers) and cut up Coke bottles being used. I for one thing trash bags or Walmart bags, doubled up several times, would be ideal, but they may not hold enough pressure to really get interesting

Lukas

[evo81]

im trying to figure out the fuel ratios 4% of what? i kno its 4% for every atmosphere but how do you calculate it? do you have a chart for the fuel ratios? and lastly is there any kind of plans i could have for this gun? thank you