Mechanical

These are views of the Thomas Orchestra Bells as I received the instrument.  I was disappointed by the synthetic casework, but discussing it with other folks it made sense for a mass-produced object from Thomas Organ Company.  The design is super simple with a row of solenoids below the tone bars.  It didn't use return springs, relying on gravity to drop the striker back into the coil.  

🎶This is the way we make the springs, make the springs, make the springs!🎶

Here's an overview of how I fabricated the striker action return springs.  The striker actions were made from salvaged upright piano dampers.  It was very handy that they had return springs, but those springs were too stiff and brittle for our purposes.  Here's a picture of damper arms with the original springs:

This is one of the early mock-ups -- I have a rudimentary windchest mounted in a frame with the double-action bellows, reservoir, spring, and air distribution.

Here we see some pallet valves I made out of solenoids.  I fabricated the stoppers with oak dowel and window foam punchings, and I fabricated the mounting plates for the solenoids.  This worked okay, but it was hard to balance the noise with the sealing effectiveness.

The Topsy 3 design calls for an air-operated glockenspiel, with leather over air pockets to push the strikers.  I just couldn't get it to work.  I might try again sometime, because it's nice to save a few magnets for other projects.  Here Korben Dalek is helping in the design and construction.

Here's a view of the hammer mechanisms mounted onto plywood plates and set in place in the instrument case that will become the glockenbox

Here we have the initial layout of the glockenspiel bars inside the hard case.  I measured clearances, etc, made the mounting rails, and found I had enough room for two more bars!  Since the driver board has 32 outs, I figured this would be perfect.  I fabricated the two lower bars.