Cylinder swept volume?

[Lordanem]

Hi

I'm looking to design a DIY gearbox and need to know the ratio of cylinder volume to barrel volume on a 'regular' aeg.

Thanks

 

[Lordanem]

If you could just measure how far your piston travels from all the way forward to all the way back, piston diameter and barrel length, thats all I need.

Thanks

 

[AK47frizzle]

On a regular AEG, the piston travels roughly 70mm front to back and vice versa.

Diameter of the piston cylinder is roughly 25mm.

Piston head diameter is roughly 23mm.

Barrel length varies, not sure what you're asking about with the whole "ratio" thing, but in my AK47, the inner barrel length is 423mm

 

[Lordanem]

That will do

Thanks for your response

EDIT: Just worked it out

2.42 to 1

 

[Rufe0]

A cylinder with a diameter of 23mm and a length of 70mm is 29cc in volume. A cylinder 6mm diameter by 423mm is 12cc volume. So the cylinder is roughly 2.5 times larger than the barrel in volume. This is vital as if it wheren't as big no matter how strong the spring you had there simply wouldn't be enough air left to push the BB.

It would be nice to know the sweet spot exactly, does anyone know of a detailed experment trying different length barrels keeping everything else equal?

 

[two_zero]

no clue.