Servo string benders attached to a Telecaster
Making the servo mounting plate
Routing the guitar body
Wipe on poly for the guitar body
Counterweights for the servos
When servos are loaded up, they will make some pretty annoying noises. To combat that, I came up with this really simple counterweight. The idea was for it to be as simple to make as possible (on a 3d printer), but also be effective and fit just about into the footprint of the servo. In order for the tensioned part of the sting (that you play) to put as little force as possible on the servo, we want it to be as close to it's center of rotation as possible (torque, etc.). So you can see it actually is tangent to the shaft of the servo and goes under that cable pulling horn. There is actually a hole drilled through the shaft of the servo, and the string goes through that. The screw in the shaft of the servo then clamps the string down, effectively separating the part of the string you play from the rest of it, which will be tensioned by the counterweight to create an opposing force.
The pedal assembly
Still breadboarded and running off a variable lab supply, but here is a working pedal assembly. The four little trim pots are used to adjust the upper limit of the bend, so things are in tune when the pedal is bottomed out.