Resonator Tubes for Marimbas

The large tooling in the previous post was made to bend resonator tubes for marimbas.  This is where my wife’s percussion world meets my fabrication world, as the marimba was the instrument she focused on through college.  The premier U.S. manufacturer of marimbas needed a source for the bent resonator tubes on a new instrument they had developed.  The tubes are 3.5″ and 4.0″ x .065″ wall aluminum bent on 8″ and 10″ center line radii.  These are some big tubes – the longest are close to 5 feet long and each has 2 bends.  The biggest obstacle is these need to be cosmetic quality when completed – so die marks have to be kept to a minimum.  It’s a real trick to securely clamp on dead soft annealed aluminum and apply literally tons of force in the bending process and leave only minimal marks!  The second obstacle is keeping them unmarked – the batch of 6 sets (10 unique tubes per set) shown in the pictures below took a massive box the size of a small car and rolls of foam packing material to get them safely to the customer in New Jersey.