Posted: Fri Apr 08, 2011 10:29 am
If the chamber is barely larger than the barrel OK, the volume will be small and the flow choked. The way to get a small ratio with a larger chamber is to have the piston in a smaller piston cylinder that is smaller than the chamber. My Dragon and Mouse Musket are both built this way.
The Mouse Musket has a 2 inch chamber with a 1.5 inch female adaptor in the breech with 1.5 inch pipe inside it to hold a 1.5 inch piston.
The Dragon has a 6 inch chamber with a 3 inch piston (2.5 inch pipe cap) with a 2.5 inch barrel.
This type of narrow ratio valve works well.
Muzzle of the Mouse Musket. Layers from outside in.
2 inch coupling
2 inch to 1 inch reducer
1 inch barrel
The Mouse Musket has a 2 inch chamber with a 1.5 inch female adaptor in the breech with 1.5 inch pipe inside it to hold a 1.5 inch piston.
The Dragon has a 6 inch chamber with a 3 inch piston (2.5 inch pipe cap) with a 2.5 inch barrel.
This type of narrow ratio valve works well.
Muzzle of the Mouse Musket. Layers from outside in.
2 inch coupling
2 inch to 1 inch reducer
1 inch barrel