11/21/2023
Holton 345 6/4 BBb tuba.
This was a tough one. Many modifications plus fabricating new parts.
It was originally a three valve, in the past a four valve block was installed badly, by basically just cutting and pushing it in.
Here it is in progress, braces are broken, the valve block is pushed into branch tubing. Tubing is cut at wrong angles, including valve knuckles, and number four threads are ruined.
We fabricated new slide tubes with angled tubing so the block fits, using lathe and honing machine to exact dimensions.
Also fabricated new top threads.
More of the process to come.