Picture of The Most Useless Machine EVER!
And yet everyone wants one!!!?

AKA:  The Ultimate Machine!

Get Your Parts Kits and Machines:

Update Oct 31, 2012:

Now Available At the Maker Shed

"Weird Al" Yankovic Sez:  "I never realized till now how much I needed one of these."

AS SEEN ON TV!  Make Magazine's amiable editor-in-chief, Mark Frauenfelder demonstrated The Useless Machine on the Colbert Report!

Useless Machine Featured in Vol 23 of Make Magazine!

Thanks everyone for all the cool comments, suggestions and all the videos! Keep 'em coming.

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Step 1: Background

Picture of Background
Also known as The Ultimate Machine: Claude E. Shannon built the first one based on an idea by Marvin Minsky.

After seeing a video of such a machine I just had to have one of my own.

The only design I could find uses a PIC microcontroller but I consider this to be overkill (not knowing how to write code for micros may have had some influence on my humble opinion...).

Additionally, the microcontroller version really doesn't shut itself off. It's circuit remains powered even when the switch is in the off position.

Knowing a little bit about servos and basic electronics, I felt sure that I could build the machine using a simple analog circuit.

My main goal however was to have the machine REALLY turn itself off.

The machine in THIS instructable accomplishes that!
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Frivolous Engineering (author)  Meuryn3 years ago
It means the the wires are NOT connected, one just passes over-top of the other wire!
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Good, thankfully I did wire it the right way anyhow.
Lol cool project
There are a lot of videos with useless machines on youtube similar with this. But elufo below has the gratest ideea with the "infinite version" lol :)))
ionutpop3 years ago
As you said, you have to appreciate the irony of such a device.

But this time I got to admit that I don’t understand the logic of this viral meme. I’ve been receiving the same link today from several directions. Nobody seems to care that it’s not a new gadget, and not a new joke. Usually the web is full of bitter commentators about “how that’s so last season”. If you bother to google with Shaude Clannon original title “The Ultimate Machine” you will find several of these.

Perhaps the best lesson is that anything (even old stuff) can become a great viral if it just hits the right people, right channels. (twitterists with influence etc.) As said by smarter people than me, meme’s (or gene’s) success is not dependent on whether it is a good meme but just in the replication efficiency.

Ionut from bwin
I really like this but made a useless squared without using two machines.
Thoth5053 years ago

I;m just wondering what the black and silver thing is at the top of the image, one of the yellow wires go to it. Thanks!
Frivolous Engineering (author)  Thoth5053 years ago
That's the diode.
Isn't that a bit to big for a diode, i can see the diode next to the resistor. Is there two?
kfoster103 years ago
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I don't think that one will work, it looks like it doesn't have any gearing.

You'll want to find something like this:

Or mod an RC servo into a gear motor...
ldiener3 years ago
In the notes to step 4, there's a reference to "wiring to the motor". There's a nice 'ible on doing this at

This reference helped me future out what that comment meant.
so i wired mine exactly like the diagram and the second i flipped the switch, the servo literally started spitting smoke and burned up! i have no clue what happened?
I had this exact same thing happen today. Did you ever figure out the cause?
Most likely something shorted out in the servo. What brand and model servo did you mod?
lukeD3 years ago
what if you are faster than the robot, and turn it off by yourself?
Frivolous Engineering (author)  lukeD3 years ago
Same as if the machine switched it: the arm retracts back inside the box.
Derpancakes3 years ago
LOL i love this!!!
ginger200373 years ago
Okay, I admit it, I loled at this xD it's so funny, but very cool
eatramen3 years ago
very cool and entertaining for a "useless" machine haha!
flydogfly3 years ago
Wow!, you wont believe this, I saw a video two days ago of a Most Useless Machine, but after a while it strated running around crazy, anyways point being I made one yesterday using my Lego Mindstorm. Cool instructable
sirfag4 years ago
thanks mate it works great exept i need a box
I just bought a nice little box over at Lowes. It's a kids "build it yourself" Jewelry Box. It only cost $8. It's precut pieces that you just tack together. May be a little tight with all the wires.....
I just finished mine, and I have to say the box was the hardest part, well making it look good was hard anyway. (I made mine from scratch.) I think going SaskView's route might be better.
jmartin183 years ago
it looks like the yellow is connected with both resistors at the top left corner post. Is this correct, because it doesnt seem in line with the diagram for wiring.
That is correct. The yellow wire is Vcc. The way I've laid out the circuit on the breadboard may look different, but it's the same circuit as in the diagram.
00bunge003 years ago
I saw a related video on you Duelling Useless Machines video about a laser triggered camera setup? Is there a page about that on here? if not, could you send me a design for it?
klio9113 years ago
So, I'm trying to build one of these things. I bought all the parts last year, before the kit was available and am just getting around to building now. I am so new to this that I think my question is too basic to be found on the internet (or I'm asking it wrong).
It is: how the hell do you connect the servo to the circuit? Is there a part that I'm missing? I know there's a servo connector available for breadboarding, but what do you do when you want to solder everything together? I feel like there's a component that needs to be added here, and have no idea what it is.

I feel like a doofus for not being able to figure this out on my own...any help would be greatly appreciated.
Frivolous Engineering (author)  klio9113 years ago
I used the female half of a servo extension cord on the first one I built, but have also just soldered in the servo wires permanently on other builds.

The servo I bought ends in a female I should be plugging it into some kind of male piece? But what?

I don't trust my soldering skills enough to cut up my servo yet...
Frivolous Engineering (author)  klio9113 years ago
My mistake, it WAS the male end that I used. Very embarrassing getting the gender mixed up. So of course, use the male half of the extension cord...

jmartin183 years ago
hard to tell whats going on with the toggle switch, I'm at the point of connecting it, and I can't figure it out by comparing the picture and mine.
Had fun putting together the useless machine kit (my first time soldering) ... But after about 15 or so switches there's a faint burning smell and brand new AA batteries are totally drained in an hour - I'm pretty sure that's not part of the design ... Any notions on the problem? I'm very new to hobby circuitry like this ...

Sounds like you've got a short somewhere. Carefully check you wiring and soldering. Make sure none of the pins on the toggle are shorted together.

Also make sure you are using the C and NC pins on the micro-switch.

Let me know if you still can't find the problem.

mvan dalen3 years ago
this is what men call useless..i think without a battery it's usesless
On my motor, it has a red, white and black wire going to a plug. for this do i just cut off the plug, strip the ends of the wires and use the red and black ones? (ignore white?)
Follow these directions for modding it into a gear motor: (

I have the motor, and it has 4 arms on it. do i sand the 3 down that i am not using?
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