The Most Useless Machine

One half of the lid hinges up, while the other half carries all of the machine’s workings. The workings all mount onto the same piece so that they’ll stay aligned.

Remove any latches and hinges on the box’s lid.

Cut the lid approximately in half through the middle crosswise, undercutting at a slight angle so that the hinged half won’t bind when opening. Before you cut, make sure the machine half has at least enough space to fit both the motor and the micro switch lined up lengthwise.

Use the pencil to draw scale paper templates of the motor, toggle switch, micro switch, and the machine half of the lid, all in side-view, and cut them out. Also cut a template for the motor’s mounting wheel or horn, and mark the axle on both the motor and mount templates.

Use the component templates to figure out the shape of the arm and how everything should attach to the lid. Download sample templates.

You want the back of the arm (or a mounting horn) to push against the lever switch when it’s retracted. Then the arm should rotate and clear the lid while its “hand” swings over and pushes the toggle switch.

Cut templates for the arm and for a standoff bracket that holds the motor and the lever switch. Refine their shapes and sizes and move the pieces of paper around until you’re sure that they all work together, while still leaving room for wire connections.

Mark the positions on the templates where they meet: the toggle and bracket’s position on the lid, and the motor and switch’s position on the bracket.

Trace the template shapes onto ¼” plywood and cut the pieces out. File and sand the edges smooth.

Mount the arm to the motor’s mounting wheel or servo horn. Drill 5 pilot holes in the arm and mount it with small screws (usually included).

Measure and mark a centerline across the machine half of the lid, perpendicular to its cut end. Then mark the toggle’s distance along this line, following its position marked on the templates.

Now it’s time to fire up the soldering iron. If your motor already has leads attached, solder them to each of the 2 middle legs of the toggle switch. Otherwise, cut, strip, and solder wire leads between each motor terminal and the middle toggle pins; 4″ long is plenty for all connections in this circuit, and you may want to shorten them later for neatness.

Solder a short jumper wire diagonally between 2 opposite corner legs of the toggle switch, then solder separate leads to the remaining 2 legs at the other corners.

Solder the 2 free leads from the toggle to the lever switch. Connect one to the common tab (marked C), closest to the lever’s pivot. Connect the other lead to the normally closed (NC) leg, farthest from the pivot. Don’t connect anything to the normally open (NO) tab in the middle.

Solder the battery pack’s leads to the 2 legs at either end of the toggle. The circuit is complete! Test it by loading batteries into the pack. The motor should run, the toggle should reverse its direction, and the lever switch should shut it off in one direction. If it all checks out, remove the batteries, leave the toggle thrown in the direction that the lever interrupts, and mark or note this direction on the motor.

Drill a ¼ hole in the machine side of the lid, at the toggle position you marked in Step 4.

Fit the toggle switch up through the hole, positioned with the toggle thrown in the direction opposite the lid cut. Don’t glue it in yet.

Hold the wooden bracket, motor, and lever switch in place against the lid so that they align properly with each other and with the toggle. Mark their positions with the pencil.

If the motor turns in the opposite direction from what you anticipated while determining the layout (if the interruptible direction turns the arm out, not in) you should reverse the connections to the motor, or else position the motor the other way and arrange the pieces in mirror-image on the opposite side of the box.

Temporarily hold all the pieces in place with a bit of hot glue. Put the lid on the box with the other half off, load the batteries, and check to see that everything works perfectly (which is unlikely).

Tweak the components’ placement and the shape of the arm as needed, ungluing and regluing with hot glue, until everything does what it should. You may need to file down part of the arm so it clears the bottom of the box, or fine-tune the position of the all-important micro lever switch.

When everything checks out, mark the final locations. Then mount the motor to the bracket with its included screws and attach the other components in place with permanent glue.

For the other half of the lid, replace (or install) the hinges on the narrow end opposite the machine half, drilling 1/16″ pilot holes to guide your screws.

At this point, you should have a fully functioning Useless Machine. Don’t wear it out!

The Most Useless Machine, like Claude Shannon’s original, is a desktop or tabletop conversation piece. I went with a minimal aesthetic that leaves it most open to interpretation, but you can dress it up by labeling the switch positions, using a recognizable object like a doll’s arm for the arm, or otherwise decorating it.

Try painting your machine with MAKE’s custom stencils by illustrator Rob Nance. Download the PDF in the Files section above.

On a much larger scale, Swiss artist Hanns-Martin Wagner built a version that used an old wooden trunk as a box, a weathered prosthetic arm, and an air compressor.

I was amazed at the response to my original Instructable. Everyone wants one of these boxes, and wants to share details of their own build! Its social appeal was also shown this past spring, when the Birmingham, U.K., hackerspace FizzPop hosted a Useless Machine-making workshop led by Nikki Pugh (seen here).

On June 8, 2010, MAKE editor-in-chief Mark Frauenfelder was a guest on The Colbert Report, where he presented the Most Useless Machine (the very one you see here) to a delighted if slightly puzzled Stephen Colbert.

Colbert liked it so much that Frauenfelder made a gift of the machine, which now pursues its single-mindedly futile existence in Colbert’s excellent company. To see the Most Useless Machine in action on The Colbert Report, check it out here.

The original viral video: The Most Useless Machine EVER!!!

For Useless Parts kits and Ultimate Useless Machines please visit FrivolousEngineering.com