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JLiang · September 23rd, 2012, 22:12

The thing is, cylinder type must be changed if your barrel length is changed.

There's a lot of math involved, of which you can go as any senior member (I personally am not going to bore the crap out of everyone with the details). Basically, the volume of the cylinder must match the volume of the barrel in order to achieve maximum results.

Think about it like this. If you have an amount, say, 60 mm cubed worth of air volume in your cylinder. When your piston pushes it out down the barrel, that volume should be enough to get the BB out, and just that. Too much is not good, and too little is not good, either.

We'll use the previous example. If you have a cylinder that has 60 mm cubed of volume, and your barrel has 70 mm cubed of volume, the amount of air in your cylinder has run out before your barrel has. Therefore, the BB becomes 'stuck' in equilibrium. In layman's terms, your BB now has to 'suck' air in order to continue going.

That was an example of a barrel being too long. If a barrel is too short, say, 40 mm cubed of volume (All these numbers are hypothetical, by the way), your 60 mm cubed of cylinder volume is not yet empty by the time the BB has left the barrel. This results in overpressure, and the excess air continue to buffet the BB after it's left the barrel. This results in unstable flight, reducing accuracy, and potentially the life of your gearbox.

GENERALLY, and I repeat, GENERALLY, the pairings of Cylinder Type to Barrel Length should be as follows:

Type 0: (No hole) 450mm+.
Type 1 (Tip hole) 350-450mm.
Type 2 ('M4' hole) 229-430mm.

Again, these ARE NOT DEFINITIVE answers. The Barrel/Cylinder volume ratio will depend on your case, and keep in mind is ALSO INFLUENCED BY BB WEIGHT.

I don't know the formula for that, but there is a large influence played by the BB.

But before you stress out, remember that there is no perfect machine in the world. You CANNOT obtain a perfect Cylinder/Barrel match, and after you throw BBs and Compression Leakage and all sorts of other crap in, you end up with a pretty flawed system.

Try to match them up as best you can, and if you know what you're doing, you'll manage.

September 23rd, 2012, 22:12	#6
JLiang Trader rating Join Date: Jan 2012 Location: Waterloo, ON	The thing is, cylinder type must be changed if your barrel length is changed. There's a lot of math involved, of which you can go as any senior member (I personally am not going to bore the crap out of everyone with the details). Basically, the volume of the cylinder must match the volume of the barrel in order to achieve maximum results. Think about it like this. If you have an amount, say, 60 mm cubed worth of air volume in your cylinder. When your piston pushes it out down the barrel, that volume should be enough to get the BB out, and just that. Too much is not good, and too little is not good, either. We'll use the previous example. If you have a cylinder that has 60 mm cubed of volume, and your barrel has 70 mm cubed of volume, the amount of air in your cylinder has run out before your barrel has. Therefore, the BB becomes 'stuck' in equilibrium. In layman's terms, your BB now has to 'suck' air in order to continue going. That was an example of a barrel being too long. If a barrel is too short, say, 40 mm cubed of volume (All these numbers are hypothetical, by the way), your 60 mm cubed of cylinder volume is not yet empty by the time the BB has left the barrel. This results in overpressure, and the excess air continue to buffet the BB after it's left the barrel. This results in unstable flight, reducing accuracy, and potentially the life of your gearbox. GENERALLY, and I repeat, GENERALLY, the pairings of Cylinder Type to Barrel Length should be as follows: Type 0: (No hole) 450mm+. Type 1 (Tip hole) 350-450mm. Type 2 ('M4' hole) 229-430mm. Again, these ARE NOT DEFINITIVE answers. The Barrel/Cylinder volume ratio will depend on your case, and keep in mind is ALSO INFLUENCED BY BB WEIGHT. I don't know the formula for that, but there is a large influence played by the BB. But before you stress out, remember that there is no perfect machine in the world. You CANNOT obtain a perfect Cylinder/Barrel match, and after you throw BBs and Compression Leakage and all sorts of other crap in, you end up with a pretty flawed system. Try to match them up as best you can, and if you know what you're doing, you'll manage. __________________ []]]]]]]]]]]]]]]]] ------)_'_\ * ( "----------\ * \ "-----------\_*_\