Disk Robot
Roger Arrick
1990s

Here's a robotic disk machine I built for a customer who wanted to computer control loading and unloading a floppy diskette drive.
The mechanical system is very fun to watch operate. A nylon plate slides under computer control to push the diskette at the bottom of the stack into the diskette drive. The drive is then tilted down and away from the insertion position to eject the diskette into one of two different bins - a good stack and a reject stack.

Two unipolar driver circuits deliver power to geared stepper motors - one for inserting the diskette, and one for tilting the disk drive to the proper location for loading or ejecting.

It's amazing how much force is required to press the eject button on a typical drive - several pounds. For this, I used a large 110VAC solenoid and a solid state relay. It makes quite a noise.

The controller is an 8052-type programmed in assembly language. It accepts ASCII text commands from a serial port and several controllers can be daisy-chained. The circuit board uses point-to-point wiring and is still operational 10 years after construction.

End