Fellow Whovians understand that Doctor Who sonic screwdriver toys are unnecessarily expensive. Here's a model of the Master's laser screwdriver (There are already several Instructables on the sonic, it's time to do something a bit more unique). This metal prop cost about $10-$15 to build, as opposed to the $30 plastic storebought ones. Use it to upstage all the other Doctor Who fans at school who think their sonic screwdriver toys are so great!
Step 1: Materials
3 sizes of copper and/or brass tubing (1/8"-1/2"); Aluminium flashlight housing; Aluminium and brass sheet; Batteries, a switch, LED, and resistor if necessary; Hot glue and epoxy; Pipe fittings or other decorative pieces
Step 2: Main Assembly
Unscrew the flashlight housing and put the cap to the side. Cut two circles out of aluminium sheet. Cut or drill 1/2 inch holes in the centers so that the brass tube can fit through but still slide freely. Add a notch in the edge of each circle, big enough for the switch to pass through. Glue these into the top of the flashlight housing, making sure to align the notches.
Step 3: Electronics
The circuit is a simple LED light connected to a battery with any necessary resistors, with a switch. If you want to add sound, search for an instructable on 555 timer synths or Arduino tone generators.
Step 4: Back End Details
The back end is one of the less important parts of the screwdriver, and I could not find parts that matched the TV prop perfectly. I decided to use some creative license, and made them out of a copper plumbing cap, a broken motor casing, and some brass tubing. Feel free to make it however you want, or sculpt and/or cast it to look like the TV version.
Step 5: The Business End
The main part of the front end of the laser screwdriver was made from aluminium and brass sheet, rolled into a tube shape. A neater, more precise version could have been made with large aluminum tubing, but I did not find it economical to buy a 3 foot aluminium pipe when I'm only going to use an inch of it. I glued three pieces of small brass tubing into the end. I recommend using hot glue because it is translucent, letting the light through and diffusing it well.
Step 6: Assembly
Cut a piece of 1/2 inch brass tubing to about 3 or 4 inches. Make three cuts in one end, and bend them out into a claw-like shape that fits closely in the inside of the front end assembly. Insert the other end into the 1/2 inch opening in the handle assembly. Place the circuit assembly in the handle, then feed the LED into the brass tube and the switch through the notches in the aluminium sheets. Glue the LED into the front end with hot glue, then epoxy the front end to the three prongs on the brass tube. Glue the switch to the outside of the handle. Add brass and aluminium sheet to the handle, to look like the TV prop.