C:B?
I didn't look at the article, but the information probably came from Burnt Latke. In the top, left corner is a navigation bar. Scrolling all the way down, it will show tests that he conducted.
Yea it shows .8:1 C:B as the best ratio. I guess I'm confused because on RatCalc it has 1 : x as a constant on the website.
According to my calculations, the test they did was with a 1.5" barrel at 8 feet (96 inches).
All we're given is that it's a 159ci chamber which in turn would be a 4" diameter 12.75" length chamber... or 3" diameter 22" length chamber.
Now thats for 0.8 ratio as noted in the value box
C:B - calculated: 1 : 0.837
So I'm just wondering if its actually 1.5:1 or 0.8:1 is actually better.
(Although isn't that technically like... 1:0.8 chamber to barrel ratio on the tool? I don't know it seems as if it's backwards.)
According to my calculations, the test they did was with a 1.5" barrel at 8 feet (96 inches).
All we're given is that it's a 159ci chamber which in turn would be a 4" diameter 12.75" length chamber... or 3" diameter 22" length chamber.
Now thats for 0.8 ratio as noted in the value box
C:B - calculated: 1 : 0.837
So I'm just wondering if its actually 1.5:1 or 0.8:1 is actually better.
(Although isn't that technically like... 1:0.8 chamber to barrel ratio on the tool? I don't know it seems as if it's backwards.)
I've never tested a combustion launcher to see what ratio is the best but here is my theory: People come up with different ratios because the test under different conditions, use different materials, and have an idea of what they think is the best conditions.
It would seem to me that the best ratio is the one that you are the most comfortable with and the most perfect conditions are the ones that you set forth.
It would seem to me that the best ratio is the one that you are the most comfortable with and the most perfect conditions are the ones that you set forth.
1.5:1 is loud and wasting energy, 0.5:1 is silent and more efficient, 0.8 is the most powerful.
A too large chamber takes too much time to burn.
A too small chamber is just... too small and doesnt give you enough power.
A too large chamber takes too much time to burn.
A too small chamber is just... too small and doesnt give you enough power.
The difference between the same test with variable barrels is that a .08:1 and a 1.5:1 ratio is the difference between a 96" barrel compared to a 54" barrel lol. But the .08:1 calculations seem accurate and reliable so I think I'll stick with those measurements unless anyone else has some input =)
I do believe the Ratcalc is backwards.
It may not matter, but I've always built my combustions (and hybrid
) around a.8:1 ratio.
It may not matter, but I've always built my combustions (and hybrid
) around a.8:1 ratio.I built my meter, then did the math. The reason was this, gas seems to fluctuate with temperature. One day, it could be 85psi (which is what you built it around) and the next, it could be 75psi (which throws off the whole thing.
I say, set it around 65 or 70psi, just to be sure it will get there.
My meter does not contain a regulator, although they are very convenient. I simply open the first ball valve until the pressure gets right. I have a popoff on the meter to release some propane if I overfill the meter.
I say, set it around 65 or 70psi, just to be sure it will get there.
My meter does not contain a regulator, although they are very convenient. I simply open the first ball valve until the pressure gets right. I have a popoff on the meter to release some propane if I overfill the meter.
So you think I should just build a meter that will fit properly on the chamber and then figure out the pressures and all that? Right now I have figured that:
Chamber = 12.75 inches long, 4" diameter
Barrel = 96 inches long, 1.5" diameter
= 42 incher long, 2.5" diameter
Meter = 3/8 inch diameter = about 6.82 inches long which seems good
Not sure if I want to make this a straight through design or a bottom chamber looping to a top barrel design though.
Chamber = 12.75 inches long, 4" diameter
Barrel = 96 inches long, 1.5" diameter
= 42 incher long, 2.5" diameter
Meter = 3/8 inch diameter = about 6.82 inches long which seems good
Not sure if I want to make this a straight through design or a bottom chamber looping to a top barrel design though.
With those sizes, you may want to consider an over / under. In a straight through design, your cannon is going to be 11 and a half feet long!
As far as the meter, yes.
As far as the meter, yes.
C:B, or chamber to barrel, ratio. This means the chamber's volume (not length or diameter) is 8/10ths the size of the barrel's volume.
Example: The barrel volume is 10 cc. To obtain a .8:1 ratio, the chamber would need to be 8cc.
Example: The barrel volume is 10 cc. To obtain a .8:1 ratio, the chamber would need to be 8cc.