Nirschl York copy piston washer thickness info...

[bububassboner]

Also it doesn't help that the design of the valves have changed over time. I have an older Nirschl (smaller engraving) and my friend here has a newer one (large engraving) and the valves are not even close to the same. His has the "metal shim" thing going on but his are built into the piston valve itself. Mine does not have this. If I can get a camera and his horn I will take some pictures of our valves to show the difference. (There are also many other little differences between our horns)

[Rick Denney]

True precision and consistency from the chotsky maker can only be attained with 100% hand-fitted chotskies. Period.

My Holton's valve ports are actually a mess. I'd be happier if the inbound ports on the fourth valve had the same spacing as the outbound ports. There is no way to achieve "precision alignment" on this instrument without replacing the valves, no matter what thickness of bumpers are used. Errors were in the range of hundredths of an inch.

Also, the fourth valve on mine had a substantially different stroke and requires substantially different bumper thickness than the other three.

Despite all those misalignments in the valves, the Holton still plays beautifully.

Rick "whose goal is reasonable alignment, long-term durability, and moisture resistance" Denney