The Useless Box

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Made by request for Matthew Knoebel, July, 2013.
Here's Matt on Christmas Day 2012 at Children's Hospital of PA.
When these pictures were taken, Matt was suffering from Leukemia.

The useless box, before and after. Obviously they're two different boxes, but you get the idea.

The inside. The motor is a 5 RPM 12V motor running on two 9 volt batteries in parallel.

Making the useless box:
Here is the concept...
...and this is the finished product.

This was going to be one of those projects that takes a few hours and works the first time. It ended
up taking many hours of tinkering and fine tuning of the layout, and several prototypes.

This was the first version. This was a nice box I bought for $6. I didn't want to cut the lid so I put the switch on the front. The lid opened and the arm came out and toggled the switch, but I didn't like the way it looked. Now the box is wrecked because there is a hole drilled in the front. We went to a craft store and got some different boxes for 88 cents each.

All subsequent prototypes were made out of cardboard.
The cardboard prototype in the wooden box. No "off" switch yet.
 The arm was controlled by touching the motor wires to a battery.
The working version with the cutoff switch.
Notice the board slides into two slots added to the box.
The box works because of the way the D.P.D.T. switch is wired. I drew a diagram so I wouldn't confuse myself.

How it works:
When the switch is turned on the motor is powered up. The arm comes out and turns the switch "off". The "off" position
reverses the voltage to the motor and the motor runs backwards. The motor stops when the arm depresses the cutoff switch.
NOTE: the cutoff switch is the Normally Closed (NC) type. When the button is depressed the circuit is open.

We bought this action figure at the dollar store to use his arm.
His hand was placed in boiling water to make it open. During
this time he confessed to being a heretic, among other things.

The hand was supposed to come out and turn off the switch.
It worked! Then it snagged on the little door on the way
back in and almost broke it, so the idea was shelved.


Inside the completed box. Everything is removable. The batteries are held in with Velcro. A bit of black spray paint keeps it dark inside. The outside was stained and coated with polyurethane.
(I think it looked better before it was stained.) The door in the lid has a weight in it to help it close.

Ready for delivery to the hospital! Everything is wiped down with 90% Isopropyl alcohol and sealed in a zip-lock bag.
How they handled the microbe covered zip lock bag, I don't know. I had to touch it, and it was exposed to the air.

Here's a smaller version I made for Andrea's dad. He named it "Gizmo".

Matt survived his ordeal. Here he is in 2016. Because of a bone marrow transplant he is now mostly German. He will be attending Drexel University to study engineering, so there's your proof.

This concludes today's broadcast.