I was fortunate enough to win a spy camera pen in a previous instructables competition, the pen soon ran out of ink or dried up so I decided that a rebuild was in order, what better than a Laser spy camera!

Step 1: The Starting Point

Most of you will have seen these camera pens, they come apart to reveal a USB connector so can be used as an external drive, in this case 4GB, as well as containing a quite good quality video and still camera. I always found the pen a bit unwieldy as it is quite fat to hold.

Step 2: The Bits and Pieces

The first parts were collected together, a pair of 1.5v button cells which have ample power to run the dollar store red laser module.
A push button gleaned from a previous laser project and a piece of brass tube that is a tight fit on the pen end of the camera pen.

Step 3: The Build Starts

To connect the laser, batteries and button to the camera some 12mm round delrin (plastic) was drilled out to accept the laser module. The module had two flying leads, red and black, testing with a meter revealed that the red was connected to the brass case so was cut off flush and the black wire was cut down to a short stub with the end bared and solder tinned. A small brass contact with a hole through the middle would become the negative contact for the battery.

A second piece of delrin, this time 16mm diameter,was drilled at one end to accept the laser module sub assembly. The other end was drilled to accept the batteries. It was drilled off centre to leave a thicker piece of plastic where the push button will go.

The laser module was then pressed into the battery holder and measurements taken get the position of the button and the positive contact.

Step 4:

The press button is one of the tiny ones used on low cost green lasers. The two brass contacts are made from 1mm thick brass sheet cut to size, bent to shape and then soldered one to each contact on the button.
The big flat pad is the + battery terminal, the other one with the long tail to the left sticks up slightly, this will ensure that it pushes against the brass tube to hold the assembly tight against the batteries.

Step 5:

The next job was to create a cut out to fit the push button, this was drilled and filed into the back of the battery holder.
Another slot was filed so that a contact could be soldered onto the case of the laser module to press against the brass tube, so completing the circuit.

The final step was to cut a hole in the brass tube where the push button will poke through

Step 6: No Going Back

It was at around this point that I took the pen end off of the USB bit and sanded the paint off all round to get a perfect fit inside the brass tube...I then cut the end off.... the point of no return :)

Step 7: The Actual Parts Being Assembled

Essentially it is ready to go together!
To assemble the push button needed to be held down to get it into the end of the tube, once slid all the way in it popped out through the hole in the brass tube, SUCCESS!