SpudFiles

im about to build my first coaxial piston valve and i was wondering if it is ok to have a small leak in the seal between the pilot and chamber (the piston will seal perfectly to the barrel). i know this will hamper the opening time of the piston but will it work if the piston isnt perfect

it has been said that the piston need to be snug enough not to fall out or turn, and loose enough to be able to push with one finger

if the gap is 1/2mm that to much

If it rattles sideways the gap is too big. A proper piston will look like it would stick if given a chance. This pipe was sanded smooth and then the piston was very carefully machined down until it just fit inside. It worked like a charm until the chamber developed a leak at the other end.
This cannon is now retired.


The Mouse Musket breech. 2 inch chamber, 1 inch coaxial barrel, 1.25 inch valve seat (sealing surface) and 1.5 inch piston.

k thanks il keep that in mind when i get around to building my piston

Another trick is that if you shine a light through the barrel you shouldnt be able to see it from the back of the piston