Day 4, Pressure box assembly

Progress at the end of the day.

The sides of the pressure box have been accurately drilled by first cutting the boards oversize, then gluing the edges together with hot glue. This glue strip is cut away after the holes are drilled.

When using Foresner bits, the large hole is drilled first. The the small hole. The cut-out for the tubes was cut with a hole saw. The waste for this will be used for the idler wheel.


The sides of the pressure box were cut using an inexpensive laser line level on a radial arm saw. This makes a precisely true cut. Shown in the second photograph is one of the case sides after planing in preparation for cutting square.

The pressure box was joined using what I think are called dado groves. This is the way Wurlitzer makes wind tight boxes. The internal frame of the bellows were also joined in this style. The laser line was also used to set these groves true.

Once all the sides are cut, they have been clamped against the small square I use for layout.

The next stage of the project will be completing the outside case and connecting the bellows and reservoir for pressure testing.