Computer based animatrons

Movement of props can sometimes kept your guests wondering what is going on. With that thought we created our "toxic trashman" and a later version of Frankenstein. Using the computer allows the head to move randomly or sequentially using a looping program. To do this project you'll need a good fine point soldering iron, electronics solder, flux, and telephone wire (CAT 5) and the parts listed below.

First things first. You'll need a stepper motor from an old 5.25" disk drive, preferably an old IBM/Tandon drive or a TEAC. You can also use stepper motors out of old microline dot matrix printer. (Save the gears and metal rods.) These drives can be found in old junk computers found at Goodwill stores, flea markets, yard sales or computer stores (don't spend more than $5) If you can't find one, check the American Science and surplus site.

A good starting point is to read the info found at Ian Harries website

Parts List
I use Radio Shack online

I have included the wiring diagrams for three separate stepper motors, there are many others though. If you have a different one, follow the directions on Ian Harries website

1 SN75468 Darlington Transistor Array
1 1N5243B 1/2 watt
Zener Diode
1 Project Board 2'X4"
25 Pin Male Parallel
Port Adapter
12 feet Cat 5 Cable
Computer power coupling


Stepper motors use four coils to move the gear in steps or degrees, normally 1.8 or 3.6 degrees per step. A twelve volt disk drive power adapter (in the computer) controls the power. A computer command program controls the movement.

The circuit is diagramed below. I use about 2 feet of CAT 5 telephone cable (available at Radio Shack or most building supply stores) to make the connections between solder points. This wire has 8 individual wires inside color coded to 4 pairs (blue, blue/white, orange, orange/white, green, green/white and brown, brown/white.) You could use any suitable wire, this just works for me (and I had 100 feet on hand.)

There are other parts on the disk drive besides the stepper motor. Don't throw anything away yet.

Ok let's put it together. Start by inserting the Darlington Array chip into the holes in the project board. I like to center it. You can use a chip holder if you like, I just carefully bend the pins towards the outside of the board. Carefully solder wires to chip pins 2,3,4, and 5. Solder the other end of the wires to pins 2,3,4 and 5 on the male DB25 parallel port adapter. Attach the DB25 to the end of the project board. Solder a ground wire to pin 8. It gets attached to the ground on the computer disk drive adapter (black wire next to the yellow wire) In the photo below I used the power coupling salvaged from the disk drive. Solder the zener diode to pin 9 of the chip. (Remember the zener diode control feedback, current flows one way only.) The other end of the diode is soldered to a wire that runs to the 12 volt connection of the power coupling (yellow wire.) In the photo below, I salvaged connection pins from the disk drive. You'll need five pins, four for the coils and one 12 volt wire. Solder a wire to pin 14 on the chip, soldering it to coil pin 1, chip pin 13 to coil pin 2, chip pin 12 to coil pin 3, and chip pin 11 to coil pin 4. Lastly solder a wire from the 12 volt power coupling wire to pin 5 going to the stepper motor. One last step. Connect the stepper motor to the 5 pins previously solder. Use the diagrams above for connections. Now verify the the solder joints are clean and not overlapping. Verify the proper wiring. Use a multi-meter to verify the connections. Verify, Verify, Verify! We take no responsibility if this blows your parallel port. I have made ten of these without fail and I'm no electronics whiz. You can also find pre-made circuit board on the web but are expensive.

The first picture shows the controller circuit board. The second picture is a KP4M4 Stepper motor found in the IBM/Tandon 5.25 disk drives. The cable running from the circuit board to the stepper motor should be less than ten feet to overcome signal loss.

OK, now you'll need the program to run the motor, MSWLogo works the easiest, it works in win95, 98 and millennium. Using 95 and above allows the computer to be used for more than 1 task such as a looping audio sound effect. The software is available for download at Softronics The program to run the movements was developed by Ian Harries and modified by Ghoulskool to allow looping motions. The program is easy to follow and change. Download it here (by saving target as) SINGLE.lgo.txt To use the program in LOGO, it will need to be renamed SINGLE.LGO not SINGLE.LGO.TXT. This is done easiest in DOS...rename single.lgo.txt single.lgo

On to phase two...Animating something