This instructable shows how to build a custom sonic screwdriver.
Because I believe a sonic is something that the builder should design, I won't be including exact measurements.

Step 1: The Innards

THE CIRCUIT

This is the circuit I used for both the sonic sound as well as for the LED. The diode opposite of the LED, actually is a buzzer/small LED. I decided not to solder the components onto a board die to the fact that it would take up a bit more room. I used a switch that closed the circuit when released as the on/off switch. That was attached at the tip of the sleeve.

THE ELECTRONICS "SLEEVE"

I took a piece of metal tubing and cut it so that the electronics would fit inside. This will slide into the end of the sonic, and will be somewhat removable so the batteries can be changed

Step 2: The Emitter

The emitter was made from a fish tank marble thing and a brass piece from a hose attachment. I epoxied them together. As this sonic can extend( similar to the 10th doctors) I made a piece out of two sizes of tubing that the emitter screws onto. Into one side of that I drilled a hole for a bolt to go through. I epoxied a semi transparent piece of tubing in the middle. The LED went inside of that. I used electrical tape to ensure the leads did not come in contact with the metal.

Step 3: The Handle

The handle was a piece of aluminum tubing that the electronics sleeve and the emitter neck could fit in. On one side I drilled three holes, on the other I drilled a bunch of holes in a row, then filed the edges to make a slot. The electrical sleeve is held in by three screws (acting as set screws). The emitter has a bolt going through the slot. When the emitter is retracted it should press the switch and keep the sonic off.