Laser Spirograph

Break out your Pink Floyd albums, because it is time for you to have your own personal laser show. In fact, it cannot be stressed enough just how much "awesome" you are getting out of such an easy to build device. Watching the patterns spiral out of this little box onto a large wall is much more mesmerizing than it really has any right to be. Most people of the people form whom I demonstrated this for have agreed that they could probably watch the laser patterns dance all day without getting board. I can only imagine how your cat might respond. There is only one way for you to find out! You're going to have to build one.

You will need:

- (x4) Paint storage cups
- (x3) 1" round mirrors
- Project Enclosure (7x5x3")
- (x3) 1.5-3VDC Motor
- (x3) 25-Ohm 3-Watt Rheostat
- Pen-Style Laser Pointer
- DPDT Toggle Switch
- 2 "AA" Battery Holder
- 2 "AAA" Battery Holder
- (x3) Control Knobs
- "AA" Alkaline Batteries (4-Pack)
- "AAA" Alkaline Batteries (4-Pack)
- Assorted zip ties

(Note that some of the links on this page are affiliate links. This does not change the cost of the item for you. I reinvest whatever proceeds I receive into making new projects. If you would like any suggestions for alternative suppliers, please let me know.)

Lay a motor flat on top of one of the paint storage cup lide. Make two marks on each side of the motor.

Repeat for the remaining two pairs of motors and cups.

Drill through all of the marks that you have just made with a 1/8" drill bit.

Using the holes that you have just drilled, firmly zip tie the motors to the paint cup lids such that the gears stick out over the edge of the cup.

Hot glue the mirrors to the center of each of the motor's gear. Try to center the mirror, but don't worry about getting it completely perfect. It is these minor imperfections that will later help form the spirograph's unique display.

Solder a red wire to the terminal of the motor labeled "+" and black wire to the terminal labeled "-".

Hot glue the motors into the center of the case such that two are side by side and one is opposite and centered between them. Basically, the laser will later need to bounce between them in a zig-zag. That said, it helps to have this entire arrangement turned at a slight angle within the case.

Using two pair of pliers, gently twist and wobble the silver laser diode head (and board) free from the laser pen's black casing.

Cut 6" of red wire. Expose 1" of this wire and wrap it around the gold ring on the laser diode assembly's body and solder the ring closed to make contact

Carefully solder a 6" black wire to the right terminal of a small surface mount component (assuming the two surface mount transistors are pointing up) on the side of the board opposite the switch to bypass having to press the switch to activate the laser.

Solder 6" red wires the right terminal lug of the 25 ohm rheostat potentiometers.

Solder the red motor wires to the center terminals of each potentiometer, such that it is one motor to one potentiometer.

Solder a red wire from either of the battery holders to one of the center pins on the switch. Solder the other red wire from the other battery holder to the adjacent pin.

Next, solder the three free red wires from the potentiometers to one of the outer pins adjacent to the red wire from the AA battery holder.

Finally, solder the red wire from the laser adjacent to the red wires from the potentiometers.

Solder the black wire from the laser to the black wire from the AAA battery holder.

Solder the black wires from the motors to the black wire from the AA battery holder.

Saw away a 2" - 3" section of the case where you are expecting the red laser to pass through after it bounces off the final mirror.

On one side of the lid, make three equally space marks at 1.25", 2.5" and 3.75".

Drill through these marks with a 3/8" drill bit.

Consider making secondary 1/8" holes for the potentiometer mounting tab roughly 3/16" to the left of each hole. These will allow the potentiometer to lay flat and keep it from spinning once mounted in the case.

Insert your potentiometers into the case and firmly secure them in place with their mounting nut.

Insert batteries into the battery holder. You should now be able to turn everything on and off using the switch.

Drill a 1/4" hole on the side of the case where you expect your potentiometers to be (ideally opposite from where you sawed away a section of the case).

Mount the power switch into this hole.

Hot glue the laser the top of the remaining paint storage cup.

Position it inside the case such that is will bounce off all three mirrors and then pass through the section of the casing that you have cut away.

Once you are happy with its position, glue the cup in place inside the casing.

Affix your pointer knobs to the potentiometers.