Picture of The Most Useless Machine EVER!

And yet everyone wants one!!!?

AKA: The Ultimate Machine!

Get Your Parts Kits and Machines: FrivolousEngineering.com

Update Oct 31, 2012:

"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.

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!
elliotnash2 months ago

The "troll machine" sounds like a pretty good name for this device. I think it would make a great prank present for a close friend.

lukeyj154 years ago
I found something similar. Make sure you watch until the end.
eruger lukeyj154 months ago

Ok, that's an awesome mod!

This one is cooler XD

ZeshanM lukeyj155 months ago

what happened there, AI!!!!!!!+ wheels.

it's the useless-inator... i thought doofenshmirtz gave up.
ah well...
get the sledgehammer
haha saw this a couple months ago, still funny!
dude this thing is sico!!!
nice video
I saw this video two days ago, and made one yesterday using Lego Mindstorm, and saw this instructable today
The exorcist meets the most useless machine ever. lol

Thanks for the nightmare :)
jimdkc5 months ago

Here's an animated schematic of the switch-only version (without crossed wires!!!) that explains how it works:

Doc_Cottom5 months ago

I used to have one years ago. It was a coin bank. If you laid a coin on the box the door would open, the fingers extend, grab the coin and slide it into the bank and the door would shut.

UselessCan7 months ago

We have one on Kickstarter if anyone interested. It's kit with 45 pieces that you assemble without soldering to create the mechanism. Not everybody has a soldering iron. ;)


Snellingkorey7 months ago

very, very good, usless it might be, amusing definately!

jmengel7 months ago

Just saw this. You've officially "made it" when your ideas are being knocked off overseas....


davidbarcomb9 months ago

This is interesting. I will try this out

Equus1 year ago
Hi, my servo is going only "forward" until it's stopped by mechanic lock. I dont know what is wrong. And sorry for my english.
GokalpC Equus10 months ago

Hi, I just built one from the schematics as well and it does the exact same thing as yours: wherever the switch is it keeps on going on one direction and on one side of the switch if you press the button it stops. so did you find the solution ?

MicioGatta11 months ago


Not really useless.

It can be used as e Cat-Toy.

but add a small, but noticeable wooden plate to the small lever-switch, then the cat can better punch it to activate the box.

in this video at 2.07 a cat plays with something like this:

in that version the arm and the area around it are covered by plush.

That looks like a small kitten in the box

Halphinian1 year ago

What are the advantages of the dead bug?

Kelly022 years ago
I want to try to make this!!

Same here!

We simplify a circuit in the machine. Only a switch with two points is used. No chip, no servo, no spring and no additional switch are used. The movie below shows its structure and action.
bdimapasoc3 years ago
Newbie question: Why are there no resistors in the wiring (referring to the design which doesn't use the 555 timer)? Are the internal resistances of the servo, batteries, switch, and wires enough to prevent an overly large amount of current from running through the circuit?

If that's the case, then is there a way to get the numerical values for these internal resistances?
You are correct. If wired correctly it is limited mostly to the resistance in motor, and it's only a few ohms (it will vary from motor to motor, but lets say 5-6 ohms).

Ideally, the switches and wire should have no resistance, but in the real world they will add a tiny bit too.

The battery, you don't worry about it's internal resistance.

To measure the actual resistance, take the batteries out and measure the ohms across the + & - of the battery-holder.

So if the whole circuit is 6 ohms and you're using 3 volts, that's half an amp of current. Extra points if you can figure out how many watts that is!
surfcurve3 years ago
Just finished mine and it was a little more difficult than i thought it would be, but worth it. I used krazy glue to hold everything in place. If anyone has an issue with your servo not being strong enough to flick the switch like it did, U can take switch apart and change out the spring in the middle of the switch ( i used a pen spring instead of original spring inside of the switch and it works flawlessly now.) I went with the simple method with the 2 switches and a cigar box which already came with a center cut in the lid. Will now make a great conversation piece on coffee table. Good luck to everyone who tries to build one!!! Well worth the few hours of effort.
useless machine.jpguseless machine2.jpg
Thanks for this. I had to do the same thing. Works great.
Right on. Sometimes you can 'break in' a stiff toggle just be flipping it on/off a bunch of times but replacing the spring, that's a new one!

hohohe2 years ago
Built a couple of machines using solarbotics Gm2 motor, toggle and micro switch. They work fine, but they shatter one time when hitting micro. Any idea on what is really happening. Motor does have a little play
Chloe82 years ago
This is so cute! there must be some ways to use them.
CrayfishYAY2 years ago
What's the name of that song on the video?
Wow! This is great! Thank you so much!
Hi can you provide me the Circuit diagram and the PCB drawing as well as the ttemplates of the Ultimate machine please. I wish to make this for a school project but i need this infomation.
Email to:yan0055@gwsc.vic.edu.au
Aaron10882 years ago
Hi I made a useless machine (the version in step 5) and I have a problem of the arm jumping on the off microswitch. basicly when it goes back in it hits the off microswitch and jumps up and down and up and down. It is not ment to do this and I dunno how to solve it. I know the micro switch is working to turn it off becuase if I press it by hand it works. any ideas?
The bounce-back problem can be eliminated by moving the micro-switch to a spot were the arm doesn't slam into it.

The Ultimate Useless Machine that I sell uses a 'cam' to activate the micro: http://frivolousengineering.com/wp-content/uploads/2011/11/06CUcam.jpg

Check the above photo to see how it's arranged. Instead of the arm crashing into the micro, the bump on the cam activates the micro and allows the motor to continue moving a few degrees before coming to rest.
for some reason.....i find this robot cute.....wierd......maybe because i find myself annoying too...

great instructable by the way!
deneen20002 years ago
Very nice! Reminds me of the mechanical novelty toy that was a small opaque black plastic box with a slit for a coin where your switch is....when you placed a coin in the slot a little hand would come up out of the box and snatch the coin. Fun!
exotictoad2 years ago

i found somthing i think u copied
Click on the link "PIC Microcontroller" above, it's the web page of the guy who made the video you are referring to.

And btw, you are linking to a PIRATED version of the original video.

So yes, I did see the video, it's what gave me the idea. But as for me copying anything....I don't agree. The video you point out, it's definitely a 'copy'.

If you really want to give credit to the originator, you might try mentioning Marvin Minsky and Claude Shannon, who are the real inventors of this device.
OMG thinkgeek found you!!!
Actually, it's not!

The 'Box' was a good first attempt at a kit.

Solarbotics sold 3200 with no hinges (you had to use scotch tape) before I stopped endorsing them.

Ten days later they magically upgraded the scotch-tape hinges to metal ones. And bumped the price up by $5.00...now that's innovation!
fessional2 years ago
Awesomely Useless xD
TheIdrees3 years ago
I am really looking forward to making this invention. However i am at a lack of anything electrical at the moment and hope to make the whole thing without the use of electricity. It would involve some counterweights and stuff but i think it is possible! I will post pictures up as I go! Thanks for the great instructable! I also added a link to my site (here) but if you don't want this to be linked on my site just tell me. Thanks again for the amazingly pointless invention!!
Meuryn4 years ago
Just a question about the wiring diagram, where the lead from the microswitch crosses over the lead from the the servo there's that 'bump' symbol. Is that just there to tell you the wires cross over or do I need to make a junction between the two wires or something different? Sorry, relatively new to all this.
mrmerino Meuryn3 years ago
Protip: the actual symbols for different things will vary according to who created the diagram, but basically, whenever you see that bump over the wire like up there, you can always assume that those wires don't connect.
Frivolous Engineering (author)  Meuryn4 years ago
It means the the wires are NOT connected, one just passes over-top of the other wire!
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?
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 http://www.instructables.com/id/Remove-a-Servo-Controller/#

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?
lukeD4 years ago
what if you are faster than the robot, and turn it off by yourself?
Frivolous Engineering (author)  lukeD4 years ago
Same as if the machine switched it: the arm retracts back inside the box.
Derpancakes4 years ago
LOL i love this!!!
ginger200374 years ago
Okay, I admit it, I loled at this xD it's so funny, but very cool
eatramen4 years ago
very cool and entertaining for a "useless" machine haha!
flydogfly4 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
sirfag5 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.
jmartin184 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.
00bunge004 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?
klio9114 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)  klio9114 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 connector...so 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)  klio9114 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...

jmartin184 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 dalen4 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: (http://www.instructables.com/id/How-to-modify-a-servo-motor-for-continuous-rotatio/)

I have the motor, and it has 4 arms on it. do i sand the 3 down that i am not using?
That's up to you. If they get in the way, or if they aren't needed then sure. The way I arranged things in the photo on this page, I'm using one of the arms to activate the micro-switch, and I've cut off another that would be in the way.
ben_k4 years ago
Here's my third machine. I added an LED array to the circuit, so it leaks red light when it opens:

Also, I made the wiring extremely neat and tidy:

Frivolous Engineering (author)  ben_k4 years ago
Excellent work!
my microswitch is not shutting off the circuit! ive tried three of them...any suggestions?
Are you using the N and NC pins? Double check your wiring.
venom15394 years ago
I don't know why but I'm starting to get the feeling that this machine is useless
This is the most amazing thing i have ever seen. Thank you so much!
jonnyman8884 years ago
Hey, i was wondering how i modified the wiring for the servo? I'm using this servo: http://www.oomlout.co.uk/index.php?main_page=product_info&products_id=235 Do i just need to cut the white wire or what? Thanks a lot :)
Here's how: http://www.instructables.com/id/How-to-modify-a-servo-motor-for-continuous-rotatio/

That servo should work, and you'll only need to mod the wiring.
Thanks :P
bio884 years ago
I wonder how hard it would be to make the servo rotate 90, hit switch, wait say, 10 seconds, then rotate/return to home. All initiated by a momentary switch! That would be cool.
Frivolous Engineering (author)  bio884 years ago
A delay would be cool, but I don't know of any way of doing that without using a micro-controller. If anyone does know, please show how.
SaskView... I'm not a pro, but, maybe an another 555 set for 10 seconds which resets or disables first one, maybe another toggle switch will be necessary.
maybe with a transistor and a big capacitor connected in series
bpfh BrunoG4 years ago
an NE555 timer circuit would do a a great time delay - just wire the current wire that runs the finger output and plug that into the NE555 trigger... you could then turn it on, leave it on a table, wait until guests arrive and have a zombie finger appear from the box after 10 minutes!!

You could also implement the circuit with a PICAXE chip and you could make random reponses to the box, and program it to do other things (like the Useless Machine that after a preset number of times getting turned on starts spinning around on the desk before turning itself off! )
capacitors. do your research. I'm not the best at this so please be safe. In one of my classes we were able to make LEDs pulse very slowly or quickly depending on what size resistor we threw in the line. I popped a couple caps by putting them in the circuit backward.
koduor4 years ago
wonderful,beatiful, useless,stupendous,...lol.inventing is fun .even if its done for the sake of inventing
You should add a video Instructable of the dueling useless machines!  I didn't even notice it until I checked back on this Instructable for no particular reason.
How could you (me), modify the design so that the time between one switching it on and the machine "reaching up" to switch itself off would vary randomly between 1 and, say, four seconds?

Use an RC circuit to create the delay between switch on and the arm starting to move, and mechanically link the arm to a rotary, multiposition switch so that it advances one position each time the arm moves. Then load the switch with different capacitor values for the RC circuit. It won't actually be random, but an eight or nine position switch with random values in it would probably be enough to seem rather random to the observer.
It would be cool to get it to do that but I don't know of any easy way that doesn't use a microcontroller.
Okay, I'll show some potential dumbness buy here goes; it may kill the batteries a bit faster, but what about adding a large capacitor on the wiper of a large value pot? With the pot turned all the way down both leads of the pot are grounded, start turning the pot up and it will have to charge up before the circuit fires...
Beatle44 years ago
Those look great. Reminds me of a bank my younger brother had back in the 60's. It was a black box with a slot on top. You put a coin in the slot and a small green hand came out of the box and took the coin. It was called "The Thing Bank". It was a gimmick built around The Addams Family tv show.
Logan D4 years ago
Update: Japan has found a way to make a useful machine of similar function

No! Bad kitty! Stop taking my money!
Kitty need to support it's catnip habit
BrunoG Logan D4 years ago
cool, you can make a touch contact with a 555 timer that detects the coin!!
The Y Logan D4 years ago
Whahahaa nice one
pye20114 years ago
Can I buy one without having to put it together (not a kit) ?
I wonder if someone will build the Most useful machine ever?
Suziob14 years ago
This may be too difficult, but is there a way that you could incorporate a small speaker attached to some device that held a soundbit, that when you flipped the switch, it would play?

(I'm thinking of something like a gruff voice yelling hey!)
i'm not really in technical stuff like this, but wouldn't the 'mousetrap' thing be possible by adding a secondary device that would only work if the first was pushed x times in an x amount of time?
Frivolous Engineering (author)  Suziob14 years ago
One of those recordable greeting cards should do the trick.
So simple! Thanks!
andybuda4 years ago
would it be possable to have an object spinning/sliding on a threaded bar....
leds would look cool if they did... also could think about electro magnets if it could throw a bolt on threaded bar then flicking a switch to reverse... food for thought
nsternova4 years ago
Hi, is there a way to make a box similar to this one:
But, instead of having it run away after "annoying" it for too many times, have it whack the person on the finger?
I'm thinking of some "mouse trap" like device.
I want some surprise pain for people who won't leave the box alone :D
First, I have to say that I really liked this one.   Useless Machines are so cute when they're babies, but look at what they can grow into!

As for adding pain inflicting upgrades to the machine, I'll have to take the 5th on that one.  One of my last comments was harping about being careful and safe makers...

nromano24 years ago
I wired everything just like in the diagram however when the toggle switch in one direction spins the motor and the lever switch stops it (as it should) however the toggle switch in the other direction does nothing any idea on what I am doing wrong?
Frivolous Engineering (author)  nromano24 years ago
Double-check your wiring. Sounds like you have the micro-switch wired wrong: are the wires going to the NC and C pins?
Got it I just rewired a new microswitch and it works great thanks
Meuryn4 years ago
It isn't the parallax servo, can't find them anywhere in the UK (apart from DigiKeyUK which charges £12 delivery!), but this looks like a continuous rotation servo, will this work?

Frivolous Engineering (author)  Meuryn4 years ago
That one should work fine. And you won't need to mod the gears, just the wiring.

I've found that the JR Sport ST47 is a good servo to mod to.
Ok, thanks!
JimsShip4 years ago
I went to solarbotics.com, and the kits are just 22 dollars, but then they charge you another 14.00 for shipping (really the post office would be much less if offered) and then 5.00 for "handling".
There's no way I can justify 40+ bucks (don't forget tax!) for this.
I could probably buy a finished one for that, but that's no fun.
Any other suggestions for the servo needed?
Frivolous Engineering (author)  JimsShip4 years ago
I hear you, but there's not much I can do. I'm hoping to get Solarbotics to drop the handling fee, but the shipping is on par with what other companies charge.

If you just bought just the electronic parts (with no acrylic case) from Digikey the cost would be around the same as the whole kit.

As for servo's, a JR Sport ST47 is a good servo to mod. Most standard size servo's can be converted to a gear motor.
I just buy the parts of digikey and after all the shipping it comes to 30 bucks.
Frivolous Engineering (author)  Awhsome4 years ago
I just stumbled onto Newark.com and their prices are pretty good. But if you're in Canada, talk to a salesperson first and ask for a discount (The Canadian prices are 10% higher than US...)
bobdoy4 years ago
hello-I built the thing and had the problem of one of the batteries exploding and spitting acid everywhere. Very Scary-I took the battery out and noticed I put the damn thing in the wrong way cause I was so excited to finish it. Well I cleaned up everything and then put the battery in the right way and everything was moving very slowly. Then started to smoke and the batteries got super hot again. do you think when I messed up and put the battery in the wrong way that I messed everything up or just the battery pack. I know I have to get a new battery pack because it is melted. but I want to make sure I dont screw this up again any thoughts?
Frivolous Engineering (author)  bobdoy4 years ago
Bobdoy let me know he found that there was a short between pins on one of the switches.

Everyone, double check your construction before putting the batteries in. When you first put in the batteries, make sure that nothing gets hot or starts to smoke.

Safety first!

chewy7474 years ago
im trying to salvage the servo from a cd drive I have laying around but I cant figure out what the servo is. does anyone have any pictures of one or could point me in the right direction?
Frivolous Engineering (author)  chewy7474 years ago
I don't think you'll find any servo's in CD drives. What I have seen is the tray mechanism used for it's gears and motor instead of using a servo.
Awhsome4 years ago
Here is mine!I remember when I made mine this site had a part number list from digi-key. Anyone know where I can score that same parts list?
Frivolous Engineering (author)  Awhsome4 years ago
Well done!

Step 4 has the digikey part numbers. (or step 7 for the original design).
Thanks! I've got another great idea coffin based. Can't wait to post it.
vanceatot4 years ago
What would be really cool is if someone made a Huge one !!!
Fashim4 years ago
I'm gonna make it have a sign that says NO. when it comes out.
freakinhuge4 years ago
Check it out! Just finished mine!
2011-02-25 15-07-02.479.jpg2011-02-25 15-07-31.000.jpg2011-02-25 15-23-21.437.jpg
Well done!
Thanks! Now to design and build v2.0! 2x smaller and 2x the fun!
Here's the one that I made, from a broken jewelery box. Thanks for the inspiration!!

Not sure why, but I'm having trouble embedding video. Anyway... here's the URL:

Looks sweet!
Would an illuminated toggle switch work? Like this one...?

That should work.
maxpower494 years ago
so is this just two switches and a servo or is there still some other parts needed
Just two switches and the (modified) servo. And the battery pack, of course. And a little extra wire and your soldering iron. That's all I used to make it work.

Just a little clarification on the modification of the servo. If you use the suggested parallax servo, it comes with three wires attached to it, red, black, and white. These are attached to a small circuit board inside the servo housing. You'll have to take the servo apart and basically remove the circuit board and connect the red and black wires directly to the servo motor.

The instructions on how to do this are listed in the URL in step 5 on this page. It's pretty simple. Just un-solder the terminals that connect the motor to the circuit board, take out the circuit board, and connect the red and black wires directly to the motor. Done. Now you have a continuous rotation servo.

Also a little clarification on the wiring diagram. I'm somewhat of a newbie so it took me a while to get it. In the diagram, the black line running from the upper right terminal to the lower left terminal on the toggle switch is a jumper wire. Don't forget to add that one in there.
Frivolous Engineering (author)  kcdecker4 years ago
Good points!
While I have absolutely no talent for making such things, I am an idea man. Paint the box black with a sign that says push for candy. Change shut off switch to a finger, add sound FX , Go AWAY! or NO CANDY TODAY! and put it on porch for Halloween.
jdege4 years ago
In the diagram in step 5, what is meant by "don't forget to wire opposite pins together"?
Frivolous Engineering (author)  jdege4 years ago
the opposite 'corner' pins are wired together in pairs. One wire has the micro-switch on it, and the other is just a short wire going from pin to pin.
So the comment refers to the diagonal wire in the diagram, not to something that needs to be done other than what is shown in the diagram?

Great. I was wondering if I was missing something.
glassgiant4 years ago
I took somebody or other's advice and made it the most useless Christmas gift ever.

kcdecker4 years ago
And just for fun, I added a styrofoam ball into the box in which I embedded a couple of small green LEDs (for eyes) and one of those recordable birthday card things. When the switch is thrown, the arm opens up the box as usual, but also the eyes light up, and the voice says "LEAVE ME ALONE!"
kcdecker4 years ago
Well it took me a while to figure out what the directions and the wiring diagram were trying to tell me but I finally got it. Brilliant! I haven't even put the box together yet and I'm already laughing. Thanks!
mara01924 years ago
would this work for the toggle switch?

Frivolous Engineering (author)  mara01924 years ago
Also called a panel mount
Frivolous Engineering (author)  mara01924 years ago
Electrically this will work, but this switch is meant to be mounted on a circuit board. The kind of toggle you want is a chassis mount, that comes with a little washer and nut for mounting through the lid of the box.
bigz4 years ago
Another useless, based CD ROM

If we are modifying the servo- connecting the wires directly from the DPDT Toggle to the motor of the servo- then why cant we simply use like a 1.5V motor instead?
I chose to use servo's because they are available almost everywhere, and are standardized, but you don't have to use one. Just about any motor should work, as long as it's geared down, and has enough torque to flip the switch.

The more salvaged parts you use, the better.

Keep in mind that another reason for using a geared motor is to prevent bounce-back from happening when the machine shuts off.  Without the gearing, motor wouldn't keep the arm pressing down on the micro-switch while it's off.  The machines arm would just keep hitting the switch, turn off then on, then off, then on....
how do i fix that bounce back, when the arm comes back and hits the SPDT switch it bounces twice. So it goes up flicks the switch comes back down and bounces twice. Do you know how to fix it?
You need to put a 'bumper' on the lever of the switch. Take a plastic drinking straw and cut a a very short piece. Glue the piece of straw to the switch, where it makes contact with the arm.

The straw should prevent bounce-back.
DeanGPotts4 years ago
Brilliant! i havent laughed this much in a long time, Making one of my own as soon as i get back from Maplin
moGuyver4 years ago
Attach one of these to the arm.

ylpihs4 years ago
Totally agreed. This is really an useless machine. But not most useless as it does make lots of people laugh....
davidpryor4 years ago
could you have two of these on both sides of the box so they just keep going as they turn each other off?
mg0930mg4 years ago
I was never sure what this machine did, but I saw it at Maker Faire today, and I really want to make one. Thanks for the instructable,
Frivolous Engineering (author)  mg0930mg4 years ago
You're welcome! Wish I could be there.
legendx4 years ago
thanx i was looking for it
D_zeno4 years ago
Amazing, the best thing I've ever seen. Just WOW XD
But where can i get cheap servo motors btw?
Frivolous Engineering (author)  D_zeno4 years ago

I've been buying servo's from the local hobby store, mostly because I don't like to wait for delivery.

But www.sparkfun.com, and www.adafruit.com have decent prices. If anyone else can recommend a good vendor, please chime in.
slithien5 years ago
you should put a plastic spider on the end of the wood and put "candy" in big bold writing on the front
Biotele5 years ago
Why don't you patent that? Then you will have the world most useless patent. You can sue useless people and make tons of money. Think of the potential and the advancements to humanity! But, by dec 2010, it will be too late. I am sure Chinese manufacturers are waiting to mass produce this machine once you lose your right to patent. BTW, i build your gerkin batteries and it didn't work :(
Lol so true. Everyone now is Chinese and everything is made in China.
elufo5 years ago
Does anyone dares to make an infinite version of the machine? ;)
Frivolous Engineering (author)  elufo5 years ago
I called it Useless Squared...
polytecno5 years ago
Another useless, based Lego, fun machine: http://www.youtube.com/watch?v=GiTjOqYUXuQ
Thanks for posting! Here is my iteration: http://vimeo.com/13967229
knex_mepalm5 years ago
I have a prank hand with the middle finger up and all the other ones down, when it opens it turns itself off while sticking the finger up.
hunter11255 years ago
Is this a party trick? Maybe paint the piece of wood like a snake or something then you could scare someone.
That would work, like those mousetrap gum cases! But then it would have a use.......:(
tompic8235 years ago
This is the first device I'm ever going to build, so I really want to make sure I get it right. That being said, I want to get cheap parts for the first build so I won't be out too much $$$ is anything goes wrong. Would the following servo be acceptable? I know it's super cheap, but I'm alright with that if it'll function in my prototype. Thanks a ton!

Don’t use that servo, chances are it won’t have enough torque. Stay away from any of the micro-sized servo’s. A standard size servo with at least 4-5Kg/Cm torque will work in most cases. Keep in mind that the toggle switch and arm length are some of the things that will determine how strong a servo you’ll need. Most of the standard servos should do the job. This one will work almost for sure: http://cgi.ebay.com/SG5010-Servo-RC-Helicopter-Airplane-Digital-Futaba-F309-/300440092283?cmd=ViewItem&pt=Radio_Control_Parts_Accessories&hash=item45f39ffe7b
Ah, that makes sense. In that case, 1.5kg/cm probably wouldn't work :P. $7.35 is still cheap enough, so I guess I really can't go wrong with that servo. Now to just find a Micro Switch, DPDT switch, and battery holder. I of course have more questions, so I hope you don't mind me asking them. Should the DPDT switch be On-On or On-Off-On (if it matters)? Also, if I could inconvenience you for another second, is there a Micro Controller on eBay that you could recommend? Your assistance is greatly appreciated, and will go far in helping this newbie put together his first "machine!"
Use an On-On toggle switch.

Concerning microcontrollers: I haven't bought any on Ebay and can't recommend anything. I know you won't go wrong if you purchase from any of the sites listed at: http://arduino.cc/en/Main/Buy
The only thing I don't like about most of those sites is they kill you on shipping charges. I'll just have to look around a bit more on eBay and see if I can find one.

As of now, I've found a battery holder and will be purchasing the servo you linked to. I also found this toggle switch (2x for $2.30): http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=280526670655&ssPageName=STRK:MEWAX:IT and so once I find a Micro Switch, I can head over to Michaels and pick up a box. I'm going to need two toggle switches (as a minimum) cause the diagram is a little hard for me to follow, so I can mess up without worry. Thanks for all your help, SaskView.
Alright, found a microcontroller that should suffice. http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=130401920586&ssPageName=STRK:MEWAX:IT
That's a micro-SWITCH not a controller. I was wondering why you were asking about controllers...remember a micro-CONTROLLER isn't a switch, it's a computer on a chip. But that one should do the trick. Just about any mini or micro-switch with 3 pins and a lever should work.
Oops, good catch. Yeah, I meant Micro switch. So for those 4 main components, it'll cost $13.36. Not bad! I'm going to order them and then see if I can't put this thing together. They're all coming from China, so it'll probably be a good 2-3 weeks before the parts arrive. In the meantime, do you think I should pick up some extra wire (for the crossover connection on the DPDT switch)?
Not much wire is needed. Chances are the extra wire from the servo will do. I try to use scrap wire, whenever I get the chance.
Out of all the components, the one I'm having the most trouble finding is the box. I couldn't find anything at Lowes, and the guy working there looked at me like I was crazy when I asked him about a wooden box. I'm going to check Home Depot this weekend and see if I have any more luck there. Where did you purchase your box?
I got mine at the Dollar Store. Craft stores may have them. Also, cigar boxes work, so check tobacco shops...
I didn't even think of the dollar store. I'm determined to find one this weekend, and will check there and then Michael's. Your help on the matter has been tremendous and I really do appreciate it. Thanks for everything, SaskView.
No problem!
So far I've received the everything but the micro switch, so I'm anxiously waiting for it to arrive. Unfortunately, the servo I received cannot be modified to continuously rotate so I will have to purchase another one.
shooby5 years ago
Seems like this could have been made without using servos. The switch turns on a motor, causing the arm to pop up and flip the switch off. A spring attached to the arm causes it to return to the box once the motor is switched off. Simplify.
Dlowe089 shooby5 years ago
I believe that the reasoning behind using a servo rather than directly attaching the arm to the motor is due to the RPMs that a non-geared motor would have even at EXTREMELY low voltage. You need the gear box that a servo unit has to ratio down the speed and add torque to the rotation.
Well, you could just hook up a servo and a spring anyway
could i just use a high trottle motor with a gear box because i saw the link on how to modify a servo and its bacicly a motor with a grear box. thanks :)
Sure can!
haha kk thannks
sirfag5 years ago
the link you give me for the servo is really good i recommend you use this link because it works (to modify the servo)
sirfag5 years ago
i finally finished it today. it works great thx for the instructions :) i must say that with the 4 battery pack its acctually goes faster that the one in the film so thx its great
weinerpoop5 years ago
Do you also connect (+) to both servo signal AND servo (+)? I'm using the parallax continuous rotation servo, btw. Also..just need a bit of clarification here..on the micro switch do we just put (+) power on NC and C (no ground connection) thanks in advance.
Just to be sure, you're not using the 555 timer, your going with a modded servo. You don't need to change anything on the gears, but you do still to solder the red and black wires directly to the motor. Remove the white wire completely. Correct on the micro-switch. The NO pin is unused.
Check mine out it also shows the insides
Hi ZombieHippie, I have a suggestion on how to fix the problem with the door not closing all the way. I was thinking that you could use a Solenoid to electromagnetically pull the door shut after the "arm" has pulled itself in. You could put a microswitch on the side of the box so that when the arm "activates" the switch it will turn on the solenoid therefore pulling the door shut :). I hope that this helps, Tesla Coil
Right On, ZombieHippie! I like how you used the bolt to activate the micro-switch. Question, were you a hippie before you were a zombie, or did you eat hippie-brains???? Peace out, brother!
whereami5 years ago
With the SPDT Micro-Switch EG4544-ND from digi-key am i meant to solder on 2 wires to the metal holes? the picture looks like there should be 6 metal poles. sorry about the terminology, don't know a thing about electronics.
Frivolous Engineering (author)  whereami5 years ago
3 pins are correct for the micro-switch (the toggle-switch is the one with 6 pins). The wires don't have to go in the holes but it makes it easier when you solder them.
NicOmbra5 years ago
Okay... Awesome! I totally want to make one, but have incredibly low electronics knowledge. Couldn't you make it so that the switch turns on a motor, but then when the motor moves the arm and turns it off, a led weight or something just uses gravity to pull the arm back down? Or am I just misinterpreting the whole idea completely?
I think the idea was to display a simple circuit that would truly turn itself off. I don't think it counts if you cut the power and it still moves. I'm new to this stuff too, but I'm sure your idea would work just the same, as long as it didn't put too much stress on the motor.
Originally I used a simple circuit and a standard servo. Shortly after this 'ible was published it was pointed out that there was a simpler way that didn't need any 'electronics': modify the servo into a simple gear-motor and wire that to two switches. Basically what you've suggested! So both designs are listed in this 'ible. Functionally, they work the same. Also, both designs fully power-down when not in use. If you're not the best at electronics, going with the modded servo is the a bit easier.

I have four differrent models on my site, all made without electronic components other than switches and a servo...

The "unplugger" reminded me of an old "bloom county" comic strip in which a computer started raving about taking over the world, then marched off until it got as far as the end of it's electrical cord, and went dead.
The furry armed one is just too awesome. You should add little tiny "claws" to it.
I wonder if there's a way to add a random delay to the arm turning it off. That would make it seem slightly more real.
LOOKS and SOUNDS Great. What did you use for the metal 'box'. :-)

Want to add sound effect?...add a Silver Christmas Jingle Bell to the Arm...whenever it activates the bell will jingle.
Javin007 920335 years ago
But then it would just seem like a cat's in there. Wonder if there's a way to add a wild animal growl to it?
The round metal shell is a sallad bowl from IKEA. The square boxes I used were some cheap tin planter boxes that nested inside esch other. I like the sound effect idea, thanks!
Thank you kindly for your prompt reply...appreciate it very much.
I came across this site by accident in searching for something else and now I'm 'hooked' on it. :) So far I've read over 400 archived posts (whew)...as well as looking at the videos.

The videos are somewhat of a problem because this new laptop only has 512 mg memory...LOOOOOng time to load.

For example...to watch a SLOW 5-minute You Tube video takes 5-1/2 HOURS to load...keeps showing a couple words at a time...need to get two new memory chips to upgrade to 2gb.

Thanks again...Take care.
eddems 920335 years ago
I think you're basic download speed is killing ya, not the laptop. check you're speed at Internetfrog.com, if you see the link near the bottom for the old test, run it, I like it's graph of upload and download speed much better.
i hear u man, my computer is hopped up, but i live out in the sticks and have dialup...i only get 24kbps at most :(
thepelton5 years ago
I got a good laugh from that!
GaryMeow5 years ago
I want one!
xxaznitexx5 years ago
Is it possible to use this motor, HSR-1425CR (Continuous Rotation), to construct the circuit? Or do I still have to modify it?

You won't have to mod the gears, but you will have to do the wiring part of the mod.
What do you think of this motor? http://www.hobbyengineering.com/H1209.html Could this be used as-is with no modifications?
Yep, it sure should! Let me know if it works good and I'll add this to the parts list.
I've got the parts on order, should have it in hand sometime next week. I'll let you know how it goes.
Well, I finally finished the box. The motor at http://www.hobbyengineering.com/H1209.html does work, but perhaps not ideally. It has a lot of inertia; once you cut the power, it continues to travel a few degrees before finally stopping. I have the motor mounted right next to the switch on the same half of the lid, in order to allow it to reach, and I have to weight down the lid to keep the motor from powering past the kill switch. Without the extra weight, the motor's inertia keeps it moving once it hits the switch, lifts the lid slightly, the arm continues past the switch, restores power, then jams. With the extra weight, the arm kinda "bounces" once after hitting the kill switch, but it works otherwise. It's also not as quiet as the metal version posted above.
Are you using 4 batteries? If so, try using 3 or 2 batteries.
That helped. I took out 1 battery, jumped the empty space with a wire. It slowed the motor down a little bit, not very noticeable, but kept the arm from flinging the loose lid completely open, and stopped the bouncing on the switch. The motor works with 3 batteries, though the lid the motor is mounted to still needs to be either weighted down, or glued down. I currently have the lid glued down at the two points where the cut was made in the wood. With 2 batteries, the motor runs too slow, and even gets a little louder when running.
This was one reason I mounted everything on the lid of the box. A couple of ideas for keeping the lid down. Attach it using hinges and a clasp, or you could use velcro, or even strong magnets. I wouldn't glue the top on permanently, because later on you may need to open it to either repair or re-align things.
I saw the video and was laughing so bad!
G.J. Dyason5 years ago
I have all the parts but I'm not sure witch wires are witch at the microswitch (in the picture) is the left the NC or C connection? My switch looks a little diffrent.
There should be tiny little letters inscribed on the plastic. Normally for a micro-switch, NC is the furthest out, NO is in the middle, and C is closest to where the lever arm goes into the plastic.
I cant find the value of C2? Is it needed and if so what is the value. if not then is there any connection needed between those terminals
C2 is not needed. Nothing should be connected between pins 5 and 6.
hello , im working on this item ive buy your listed toggle switch , and says on- off -on so i have a momentary toggle switch in this project is useless right ?
I was going to ask the same thing, the switch listed online is on-off-on, not on-on. I don't think there would be a difference with continuity, but I personally believe it would be annoying to click the switch twice to turn it on.
sorry i still dont understand what kind of toggle switch use , on-on , on-off - on-off-mom ? im very confused
I don't think an on-off-mom switch would do you much good in this project but I'd love one for when I don't feel like doing my laundry or making breakfast
so what kind of switch i must use on this ? i still dont understand
Try to find a 5 amp on-on switch. You only want the thing to click into two positions. Using the on-off-on would be annoying because of that extra click in the middle. Now I say "try" because I've had difficulty finding one, but it doesn't have to be 5 amps. Anything rated higher will work, and SaskView has said that 3 amps would work, although I personally wouldn't recommend it. Janzak- nice joke.
This would be perfect. I'm a little annoyed that it's so hard to find a DPDT switch without a middle setting. PLEASE correct me if I'm wrong but this thing should only click into two positions. http://www.galesburgelectric.com/McGill-1121-0003-DPDT-ON-ON-6-Amp-Toggle-Switch.html
Hey guys I know for sure now that anything 3 amps and up is good. Also, as long as the switch is DPDT and only has two settings, it's exactly what you want. I went out and bought a 3 amp dpdt switch at Radioshack for 3 bucks and it looks like it's going to work fine. It actually has a faceplate that says on|off, but don't let that deter you, it should work anyway if you wire it right. Plus, if you don't want to see the faceplate, you can remove it!
You sir are my hero. THANK YOU!!!!
Haha sorry. I had to.
hippyland25 years ago
I cant view the video can someone please explain to me what this does?
it turns itself off, lol... you turn the switch and an arm comes out and turns it back off
diesel087795 years ago
in what scheme is the 555 timer being used? i'm a beginner in electronics but i can't figure out how to get this thing to work... i think maybe i have the wrong switch?
If you want to use a standard, unmodified servo then you need to use the 555 timer circuit to control the servo. Or you can do away with using the 555 timer circuit by modifying the servo, changing it to a simple gear motor. Using this method, only the switches and battery are needed. No control circuit is needed. Which ever way you go, the toggle switch is the same: a Dual Pole, Dual Throw (DPDT) switch.
hmmm... i think my problem lies within the switch, i think i have the wrong one. The switch has three positions, no two... didn't notice that before, i'll try that now. I just realized my question was a little vague, the timer that is being used, is what scheme is it being used? : monostable, astable, pulse width, pulse position... thats what i meant :)
garrickg5 years ago
i'm trying to troubleshoot my circuit. A big problem I'm having is the battery overheating, and smoking, even when the microswitch is pressed down.
Frivolous Engineering (author)  garrickg5 years ago
Double-check how it's wired up. Most likely there's a short.
sonogo5 years ago
nice job! what was in your mind to end up with this?
Frivolous Engineering (author)  sonogo5 years ago
Like usual, very little! Though it was cool, but never expected ANYTHING like this.
14kennisb5 years ago
I just saw this on the Colbert Report, good job on getting on there! If i have time ill have to check out the book, even though i hate books, but yours seems very interesting! Good Job!
mara01925 years ago
does the main toggle switch have to be a 5A switch? digikey is out of stock on them and all i can find elsewhere is 3A
Frivolous Engineering (author)  mara01925 years ago
3A should be fine. There's not too much current to worry about.
unominame5 years ago
i seen this on last night around midnight on colbert, haha "can i call you larry"
ookikies5 years ago
It's like he's battling with it around 0:15
pinky1125 years ago
stuuf5 years ago
haha, this was just on colbert!
Frivolous Engineering (author)  stuuf5 years ago
My mind is officially blown!
Thegaber7775 years ago
 I'm sorry if I missed this, but what do you use for the arm? Have people just been making it themselves? Is there something I could just buy?
Most are making it out of plywood, but some folks have used doll action figure arms.  There's even a furry paw on one!

Don't forget to post a link to your creation.
kenchato5 years ago
Use a plastic finger  =P  more funny.
i think the wooden bar is funnier
mramir5 years ago
The easiest place to find wooden boxes (sometimes for free) is at cigar shops. They often have many different empty cigar boxes in all shapes, sizes and colors.
xxaznitexx5 years ago
I completed the circuit as shown in the diagram, and the motor turns a full 90 degrees. however, when it hits the switch, the motor doesn't do a full 90 degrees back. Instead it does about 45-60 degrees back. Can anyone figure out why? Is it the resistor value problem or some wiring problems...?
You're using the 555 timer?  If so, step 9 talks about aligning the arm.

Let me know if that helps!
darichar5 years ago
You can also find boxes like these at an AC Moore, or any other crafts store...
twocvbloke5 years ago
I'm sorry, but this device is not useless at all, it's a tool for instilling amusement... :P

I like the furry fingered one below... :D
Fishpail5 years ago
Maybe I'm too simple and I would enjoy a single button that just makes a sound, i say it's more useless than this sweet machine.
92033 Fishpail5 years ago
Then put a button on top of the box with a doorbell buzzer inside. :-)
Betsy695 years ago
92033 Betsy695 years ago
WOW! What an impressive set of photographs detailing fine German Craftsmanship. I WANT ONE, :-)
Frivolous Engineering (author)  Betsy695 years ago
It's coming along GREAT!
jimipop5 years ago
Hello saskview !

Thanks again for your advice ... now it perfectly works !

just another question, i'm a beginner in electronics, i want to "pimp" my box with a led so where could i connect it to make it light when it's on ???

a bientot!
92033 jimipop5 years ago
See my post I just made above...regardng use of a Electronic Flash Unit from a Disposable recycled 35 mm film camera...sounds like a fun project to build and use.
Frivolous Engineering (author)  jimipop5 years ago
Connect the led to the switched power:  the pin on the toggle switch that is connected to pin 8 and 4 of the 555 chip.
tww1fa5 years ago
 I just finished my ATTiny13 based version, which at the suggestion of my wife I'm calling The Ornery Machine. I'll draw up the schematic and post the code shortly. Here's a video of it in action:

92033 tww1fa5 years ago
WOWZERS!...Really Great. I like the slowere action moving hand so it can be seen, as opposed to the super-fast models that happen so-quickly you don't grasp what really happened immediately.

Here's an Idea...

When the arm comes out, a BRILLIANT FLASH occures at the same time.

Take apart one of those 35-mm film cameras (throwaway model that's recycled). After the roll of film is exposed completely, remove the roll of film from the camera and just take the film in for processing.

The AA Battery and Mini Powerful Flash unit are yours to remove...install in your Useless Machine Box...and...'WALLAAAA'.

Someone can figure out how to wire it into the circuitry, I'm sure.
If you do, please let me see it in action...Thanks.
misemono175 years ago
I am going to make a large of for Next Halloween. Kids can hit the swith and either a monster or skeleton hand will come out and turn it back off. Is it possible to include a loud roar sound?

There is a humorous Santa Claus novelty where Santa stands with his back to you...pulls down his pants and farts. I envision one of these Santa's in the box...push switch...Santa pops out and does his thing and hides again for the next switch-pusher. :-)

This requires someone with half a brain to build, of which I don't posses, so if anyone can figure out how to make it, I'd appreciate a 'look-see'. :-)

toben2225 years ago
Hi, I built a useless machine for myself, and i just wanted to add that i had huge difficulties with the circuit which is given here. You better use Potentiometers and a Oszillograph to adjust pulse length and distance (rather then just resistors). and you might add a condensator between x and -. 

When the servo turns, voltage shrinks, which will reduce the pulse length, which might make your servo turn back and forth like hell and might destroy it. so i just added another 6V power which just powers the servo, pulses are powered by their own 6V.

kaptaink_cg5 years ago
Just finished mine! Built out of a cigar box.  I used a cardboard template for testing the arm, but it was still difficult to get just right.  Check it out:

Hi Kaptain...

GREAT JOB...looks swell. If you read this drop me a line at my email address...Take care.

~ ED
Nicely done!
TSC5 years ago
Cool!!!!!!!!!!!! 5stars!!!!!!!
 DO WANT! 5*~!
MegaMetal85 years ago

thepelton5 years ago
I was thinking you could put a digital light up display on it that is stuck on 42.
tictaclad5 years ago
 whats the total cost?

hippyland25 years ago
but what does it even do?
nothing that's why its so useless XD
 Watch the video.

When you turn it on, all it does it turn itself off again--it serves no other purpose and therefore qualifies as "useless".

It's comparable to the invitingly large red button that Arthur Dent found onboard the "Heart of Gold"
"I wonder what happens if I press this button..."
"I wouldn't!"
"What happened?"
"A sign lit up saying, 'Please do not press this button again.' "
Heheheh!  Hitchhiker's Guide to the Galaxy is one cool novel.
I was forced against my will to read it as a class novel and it turned out to be a great book!  I ended up reading ahead and finished the book a few weeks before everyone else did.
 The first one of these was actually built at MIT and was called the "leave me alone" box. this is what inspired Douglas Adams to add that invitingly large red button to the starship heart of gold.
monboy105 years ago
this works great i built one this way and was super simple and i am only 13 years old. it took  lots of tweaking but it was awesome when i got it right. it works fine until someone get scared and drops it :( oh well it simple to fix.
ARJOON5 years ago
everyone want it now. i will definitely make one now
sungam3d5 years ago
I was looking at the design and circuit, seems a bit to complicated for new people to work with 555 timers, resistors and all that.

I have come up with the same circuit but simplified to just 2 switches, motor and battery.

Much easier I think.

txoof sungam3d5 years ago
I started out with your circuit because it looked so much simpler, but unfortunately I didn't understand that a servo isn't a plain old motor.  

 Your circuit works great with a plain old motor, but won't work with a servo that hasn't been lobotomized.  The servos expect a pulsed input to drive them that the 555 timer supplies.  If you rip the guts out of a servo or just solder leads directly to the motor this method would probably work.  I don't know what the voltage rating is on a "standard" servo however so you might want to be careful if you were to do that.

Thanks for the great schematic though!  It certainly is easier to build than the version with the 555.

What a waste of a servo! They cost like four times what a motor costs!
 The big advantage to using a servo is you get the gear box with it.  If you're more careful than I was, it is trivial to solder leads directly to the motor terminals and leave the rest of the circuit intact.  Then, should you want to use the servo for something else later, you just de-solder the leads and go on your way.
doryrhp txoof5 years ago
I'm not sure what a servo costs but I used the motor and gearbox available at the following site:


It is basically the mechanical bits of a servo without the electronics.
Plain servos are actually pretty pricey...you can find them anywhere from $10 to $100, depending on power and build quality. However, that is probably because of all the PWM circuits for driving it. Those circuits are left out, hence the extreme price drop.

And if you only need small 7.5g or 9g servos, you can pick them up on Ebay for $15-$20 for 6 including international shipping.
Thats how i built my useless device. Much easier to build than the other way in my opinion.

Heres some pictures  :

http://img694.imageshack.us/i/pc100029.jpg/ - finished device
http://img190.imageshack.us/i/pc100028a.jpg/ - push button used to break circuit
http://img709.imageshack.us/i/pc100027a.jpg/ - inside device
http://img94.imageshack.us/i/pc100026.jpg/ - electronic components
Won't that eventually hurt the motor though? It will constantly ram the side and grind gears!
haha, im not sure. This is the first device ive actually built :)

There doesnt seem to be too much force imparted onto the gears, so im hoping it will all hold up nice.

Does it still use a timer circuit? if it does then there's probably not too much to worry about. What I was worried about is like when you don't let your cd drive open and it burns out the motor.
Oh i see what you mean.

Well, when the lever comes down, it holds the push button down inside the box and breaks the circuit. So, the whole device is turned off without using a timer.

Gotta make sure the motor has a gearbox btw, otherwise it wont hold down the button while theres no power.
Nice idea!
...definitely agree!!!
SURE is worth to use a simple wire-switch method instead of a 555 and other electronics components!
Compliments for the NEAT schematics!!!!
MaXoR5 years ago
I laughed so hard, and only 2 minutes after I got up too!

This is amazingly funny, as a mechanical joke device. The other suggestions would work well, like the wait timers, and such. I believe that hand one with the three second timer would be the best option for this, however.,...

.... this is your instructable, and you are showing us what YOU made. I like the construction, and simplicity that yours has, mostly because this will apply to a larger group of people,. than just those that want a creepy finger to pop out.

Yours could be set out on a table, and used by adults during a coffee break, or tea time. It makes you think, and not just laugh. Kids like simple pleasures, adults should at least attempt to challenge themselves....IMHO
Frivolous Engineering (author)  MaXoR5 years ago
Your welcome, I'm building one for my 56 year old father. He was in a car crash a few years back, and since then has been unable to work because of an increase of pain from his scoliosis.

He taught me everything I know today, and I'm sure he will be thrilled to have one of these for his own amusement (And others he has over, I'm sure).

I'm now 23, and live in my own place, so he will truly get a surprise.... he won't know I'm building it!

Have a good day,
poorsob MaXoR5 years ago
That is a very nice thing to do for your Dad.  He will love it.  How could he not?
Whizzman5 years ago
Since I couldn't find an answer to this question: How is C1 poled? 
Frivolous Engineering (author)  Whizzman5 years ago
The positive lead connects to pin 2.
ab3125 years ago
the original wires from the servo when you put them on the motor can you cut the connecter piece off of the wires and use them as hook up wires.
Frivolous Engineering (author)  ab3125 years ago
THank you now my next question: I have everything here. all set up with tthe direction the pieces are facing in the diagram. what about the DPDT switch is it off in this or is it turned on?
Frivolous Engineering (author)  ab3125 years ago
One thing to keep in mind:   If you are building the continuous rotation version and you find that the servo is running backwards (IE: when turning the box on, the hand moves away from the switch) then just swap the wires going to the servo.
It's an on - on switch so it doesn't matter which way you set it up to begin with.
gabrielsan5 years ago
Five stars for the awesome robot! I LOL'd 
sdtacoma5 years ago
Awesome! Awesome! Awesome!

I do not recall when or where I first saw this machine but I have wanted to make one ever since. My knowledge on processors is non-existent too, so I am glad to see you made it without those parts.

I gotta make this now and will post pics when I do. Great job!
Frivolous Engineering (author)  sdtacoma5 years ago
WilderLust5 years ago
who says machines do not have a sense of humor? this is the physical manifestation of a joke through a machine... i love it :-)
CozmikDawn5 years ago
This is a funny machine. You could really turn this into a good joke, tell someone that they have to do something before the machine turns itself off or that they have to outsmart the machine. I'm not very good at practicle jokes. I don't know why, but it reminds of those stupid cards they had in the mid 90's. The ones that had you keep turning them over and over for a stupid answer. Of course now I can't remember what exactly they said, but it was reduntant. 
KenCan5 years ago
How about:
- a rubber finger or glove to cover  the wooden arm?
- a doll's arm lashed to a shortened wooden arm?
- a dime store rabbit's foot?

please try and then post, somebody! I'm creeped out already
Dale4095 years ago
 At about the same time as the Adams Family was a first run TV show they had a box like this for sale in Joke shops in Australia. It consisted if a plain black box, sometimes coffin shaped with a toggle switch on top. when switched on there was a groan from the box and after a short delay a green hand would come out of the box and push the toggle switch off.

It's a much more amusing effect with a second or 3 delay between the switching on and the switching off.
dsi1 Dale4095 years ago
 I remember this "monster box." The one I've seen was activated by placing a coin near the door which starts the motor sound. After a few seconds, the green hand would slowly come out,  grab the coin and rapidly snap back into the box and shut off. 

I agree that a lot of what's funny is due to timing and adding a few seconds delay would make the box funnier. Adding a countdown display and a beeper would make it funnier and add some suspense. :-)
hellstudios5 years ago
it must be hell trying to change the batteries on that thing.
sxdemon5 years ago
this thing is awesome!
aliah5 years ago
Bad news, I saw something similar used to scary people: you push a button and a wooden snake pops up to attack your finger :) Everyone jumps the first time and everyone wants more :)
jeremys985 years ago
what does the white wire do on the parralex servo motor
Yep, it's the control wire.  If you are going to modify the servo for continuous rotation it's not needed.

If you are building the 555 timer version, this wire is connected to pin 3 on the timer. 
I believe it is the control wire.  You use it to control the angular position of the servo arm.
Troyboyd5 years ago
 made me laugh so hard xD

Build-a-Bear sells these little devices that you can record something, and playback via pushing a button on the front.  It's meant to be put inside their teddy bears, but found it was a cheap and easy way for me to add sound.  I decided I didn't like the sound though.  Seems like the simpler the better for this fun little activity of building this.

useless.jpgBuild-a-Bear Sound.jpg
akula1695 years ago
For some reason, the one I built is eating batteries. 

More research shows that I get about .1 volts when I read across ground and common on Switch2 when it is in the closed position.  I'd imagine this value should be zero.  Am I wrong?

Does anyone else this bleeding voltage issue?

You should see the battery voltage across ground and S2 common. The circuit should not consume any power when in the closed position.  You must have something wired incorrectly.
chuckyd5 years ago
I didn't read through all 500+ posts to see if this has already been suggested, so here goes. What if, after throwing the switch, the box made an obnoxious sound until the hand came up and turned it off? How would you add this feature?
russm chuckyd5 years ago
I too wanted to add sound.  I bought a little motor for $3 at Radio Shack that has a cam-like eccentric on the shaft so when it runs it vibrates.  I wired this in parallel with its own switch so I could shut it off if it got too obnoxious.  I built a little1" X 1"  compartment in one corner of the box and had this motor just lying in there.  When the juice came on, the motor jumped around and make some noise.  Then I added three empty 9mm brass cases, so the noise was more like a clatter.  Too much.  I then mounted the motor by drilling a hole in a small piece of wood , sticking the motor in the hole (very snug fit) and gluing it inside that compartment.  Now it just buzzes. Actually, it's more of a howl.  Cool.  Doing it this way doesn't really require a compartment.  Just glue the mounted motor somewhere inside the box.

Frivolous Engineering (author)  chuckyd5 years ago
Hard to say, it depends on what you're going to use for the sound.

I would think you could take the guts from a talking greeting card (or something like that) and have the lid on the box switch it on.

Aquilla5 years ago
This is the greatest thing ever built since the pyramids.
JakeTobak5 years ago
I want one now.
I want One Machines will be in Wallmart any day now!
Are you serious about Walmart or Just Kidding?
Just kidding, but it would be sweet!
FrozenStar5 years ago
so awesome...
tniemuth955 years ago
 the micro switch from digi-key isnt there anymore, or atleast the part number changed.  Could u find another one from digi-key? I'd rather not have to make separate trips/ buy from other places and pay addition shipping and handling
 that or find a motor that will work from radioshack, I would prefer to buy from radioshack but if they dont have one I will buy from digi-keys.
Can't find any servos listed at Ratshack.

EG4544-ND comes up on DigiKey, but it may be just on the Canadian Site.  Can you confirm that this is the one you are searching for.
There's no difference between the US and Canadian Digikey sites, they have the same stock.  They just list prices in Canadian dollars instead of USD.
 hmm, i got it to work.  for some reason it wasnt working last night. Thanks!
 I love the Idea! One thing that would be cool is if you made one that had two sides and it would flip it and go back and forth. Then you could have a switch on the side that would turn it off.
goedevraag5 years ago
hallo, dit is mijn most usless machine

cr19915 years ago
I Follow the continuous rotation servo diagram but I cant get the DPDT switch directions to reverse the motor? It goes (off on) instead of (on on) even though its a (ON ON) switch.
DPDT switch


DCMotor Fisher Price

Any Ideas on the problem???

tydarby cr19915 years ago

I sent you a PM.  Check out how the microswitch and how it is wired.  Could be wired incorrectly.  

russm5 years ago
Okay, I've built it using the simplified method and it works great.  Everyone I show it to is delighted, and I myself can't stop playing with it.  Now I want to add sound.  There are toys out there that have some kind of chip that cycles through a bunch of phrases , one each time you push a button or whatever.  Some of them are of the adult variety with rude words and phrases.  So, two questions:  one, where would you go to find a chip like that, and two, if you did find one, could it be wired into this circuit?  Failing that, could you add a buzzer or something that would give it more of a sense of life?
Samamam5 years ago
hello, does this circuit completly eliminate the need for all of the other components like the resistors and capacitors?
Frivolous Engineering (author)  Samamam5 years ago
Yep!  Just wire it up like in the diagram.
 this seems very complicated 
Match Book5 years ago
 This absolutely needs a voice box that screams "STOP IT!"
tydarby5 years ago
Part 2 "How to make" is now complete.

Part 2 Below.

Part 1

Morriscow5 years ago

muskogee5 years ago
what store was it? dollar tree , dollar general? thnx!
Frivolous Engineering (author)  muskogee5 years ago
The Dollar Giant Store, but I've seen 'em at others.
dumes795 years ago
If I was going to use the modified version without the electronics could I just use a DC motor instead (like the one in an old VCR) with a gear glued to the shaft?
Frivolous Engineering (author)  dumes795 years ago
It's a 'gear train' meaning several gears that change a high-speed, low torque motor into a low-speed high torque.  Best to use something that has that built into it instead of trying to make it from scratch.
Cool Thanks.
kelseymh5 years ago


Frivolous Engineering (author)  kelseymh5 years ago



I think Kelseymh is referring to the Machine being voted “Robot of the Year” in the 2009 Engadget Awards Reader’s Choice:




It had some stiff competition even if you don’t count Roxxy the sex robot…

tydarby5 years ago

I just finished a "How To" video on how I built my box.  Part 1 mainly focuses on putting together the guts and modifying the servo for continuous rotation.  Working on Part 2 that will be about putting the box together. This version does not use the 555.  I bought two the other day and have to learn from scratch how to use it.  Going to be fun.

Hope you like it.

tydarby tydarby5 years ago
Direct link. http://www.youtube.com/watch?v=VVuqvb5hO18
Frivolous Engineering (author)  tydarby5 years ago
Very well done!  Thanks.
muskogee5 years ago
can i do this with a continuous rotation servo? i have one frome my boe bot
Frivolous Engineering (author)  muskogee5 years ago

I was calling it a modified servo and didn't make it very clear.  I've made some changes to the 'ible to correct this.
russm5 years ago
I'm completely lame on electronics, but I did try the circuit with the 555 timer.  Failed miserably. It's just dead as a doornail and  I don't even know where to begin tracing the problem.  Anyway, now I put a circuit together using TYDarby's diagram with just the servo, two switches and battery pack.  It works, but with this limitation (it if is a limitation):  the micro switch only cuts the power with the dpdt switch on one position.  This means I can make the box work but I have to be careful to install the dpdt just the right way. 

I also looked at Qwerty9586's diagram, but it looks like the dpdt switch is wired differently.  I can't tell though, because his numbering of the terminals isn't clear to me.

Anyway, what a cool project!
Frivolous Engineering (author)  russm5 years ago

I would say you've got it right.  The micro-switch only comes into play when the servo is returning to it's off position.

Both diagrams are essentially the same.
Azayles5 years ago
What a brilliant whimsical lil machine, love it!
You could have a more complex mechanical arrangement whereby a head pops up and a hand reaches out to press the switch off before descending into the box again :P
Maybe even have a small electromechanical counter labelled "Times disturbed:"
KnexFreek5 years ago
 dude.... its rated so high its hard to click 5 stars!
cr19915 years ago
I like using stuff i have laying around, so just to clarify
Can I use a DC motor out of an old RC car? (Torque to low?)
Use an old 6 Volt cell phone charger (Volts needed?)
Then just get a toggle switch and micro switch and wire it up.

I can see why this is has a 4.7 rating :)
You should be proud!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Frivolous Engineering (author)  cr19915 years ago
Should be do-able.  Only problem you might run into is if there isn't enough gearing in the motor.  When the motor actuates the microswitch turning the circuit off, there needs to enough gearing so that the motor stays pressed against the switch, keeping the power off.

If not enough gearing, the motor keeps bouncing off of the micro, power comes back on, motor hits switch again...
coldcash5 years ago
Click Here.  Pin configuration.  Look for the notch.
cr19915 years ago
WOULDN'T a continuous rotation servo eliminate the need for modifying the servo?

Frivolous Engineering (author)  cr19915 years ago
You are correct.  I didn't know they had them at Digikey.

Thanks, I'll add this to to the parts.
I thought this was soooooooo funny!
qwerty95865 years ago
This is such an awesome tutorial! I ended up building one myself, but the mechanical parts are too complex in my machine. The circuit is actually the simplest version of the ones posted. I didn't feel confident about ordering a servo and modifying it and end up breaking it so I used a power door lock actuator out of a Volvo instead (which is a DC motor with a gearbox that pushes/pulls an arm). I really should have used a modified servo since the lock actuator took a lot of aligning to make it work properly (and the arm jams if the switch is held on since the actuator maxes out the travel by that time and the taped battery is suppose to keep the momentum going). Chalk it up to experience I guess. Tried my best to make it look presentable just to hide this shortcoming with the actuator. Anyways, here's my video if you want to add it to your playlist.

I'm glad you built it the way you did.  I salvaged parts every chance I get.
Thanks! Oh, here's the diagram I have in the video. You can use this for the "Modified Servo Circuit" wiring diagram. I don't know why Instructables made the image half the original size (it wasn't very big to begin with).
I like the simplicity of this circuit but in the video I believe the arm moves too fast... if I added a resistor to one side of the motor hook up would that slow the motors movement either coming out or drawing back?
Frivolous Engineering (author)  SWV17875 years ago
From what I've read, that will also reduce torque and then the servo may not be strong enough to flip the toggle.  You'd most likely need a low ohms, high wattage resistor.  I'm guessing here (I don't have any resistors to test this) 5 or 10 ohms, 2-5 watts).

A simpler way would be to use fewer batteries, only  2 or 3 AA's.  This is going to have the same effect as above.  I've tried 3 AA's and it did slow it down a bit, while still having enough torque.

I've read that the only way of slowing down a servo without sacrificing torque involves complicated microcontroller circuits.

Mine has the 3 AAA's.  Work great, but it's fast.  Tried 2 AAA's, it moved great but no torque to move switch.  Went back to 3 AAA's.  Gotta learn 555!


I actually had to use two 9volts in the end for that actuator (because it originally ran on a 12 volt system). One 9 volt would not last very long because when it dropped below 8.5 volts there wasn't enough torque to get the arm moving fast enough to even lift the flap on the top of the box! One brand new 9 volt did have the right speed, it was just too bad it didn't last very long.
joeuxi5 years ago
 i have seen some that when the arm comes out it is so fast that it might take your hand off and some are slow how do u make it that it goes really fast 
Frivolous Engineering (author)  joeuxi5 years ago
See my reply to SVW1787.  I should add that the type of batteries used will make a small difference.  Alkalines have a higher voltage than rechargeables, making the servo faster.

Also, some servo's are just plain faster than others.
insane26425 years ago

I'm having problems with my servo, it only rotates in one direction.
I haven't modified it, and I can't see any difference between my circuit, and the ones shown here. BTW I am trying to use the 555 circuit, and don't really want to crack open my servo!

Thanks for any help.
It's possible that the timer is generating a usable signal for one direction but not the other.

Check and see which toggle position it's not working in and the corresponding resistor (R2 or R3).  Make sure things are wired up correctly for that part of the circuit.

If things are wired up right, then you can try changing the valure of the resistor.
If it's R2, try using a slightly higher value.  R3 slightly lower value.
Thanks for your help.

I think what happened was the connections to the toggle switch were a bit dodgy. I got a soldering iron today and put them in, and now it works like a treat!

Thanks anyway, and thanks for the instructable!
dashi5 years ago
The extra terrestrial every one loves? This is awesome.
codongolev5 years ago
I saw one of these once, but instead of a little thing slowly pushing the switch back, a giant furry paw flew out and switched it too fast for you to see what it was. great to just leave somewhere and let curiosity take it's course.  
tydarby5 years ago
With as much interest as this little box as here and all the questions about it, I thought a website with a forum would work out nice.  If you interested check it out. Free to signup .


Post pics, videos, ask questions in the forum, share ideas, projects, live chat & a personal page for each member to display stuff about their Useless box.

Frivolous Engineering (author)  tydarby5 years ago
Great Idea!
jmartis0045 years ago
I decided to try the modified circuit but when I toggle the switch nothing happens. Everything looks to be wired okay and the batteries get hot but thats it. Any suggestions?
Batteries shouldn't get hot.  Sounds like you have a short somewhere.  All I can suggest is check the wiring, including the modded servo.
darn. okay so the wiring looks good. Do you think somehow i could have messed up the modded servo and need a new one?
Possible.  The mod you did was wiring the servo leads right to the motor inside?  If so, hook the battery directly up to the servo to see if it runs.
okay, so I think I got it working. Ill let you know how it turns out.

Thanks, Jarrod
tydarby5 years ago
I have NO idea what to do with a 555.  I have zero experience with electronics let alone IC circuits.  But this little box has really perked up my interest in learning about it.  

Came across this the other day while searching for info.  Has a cool animation on the workings of the 555.  I still don't understand them but it's a start.  Click HERE.

dmheiland5 years ago

Doing the version without the 555.  Box sorted, wiring sorted, components sorted - one last question.

The way I understand things is as follows:

- Turn machine on with DPDT (main) switch
- Arm starts turning and moves away from from SPDT switch (inside), arm keeps rotating
- Arm switches DPDT switch off, and reverses direction
- Arm continues until touches SPDT switch, cutting power

Right?  But at the moment, the spring on the SPDT switch is pushing the arm back away from it, turning the current back on and moving the arm back to switch it off.  So it keeps switching itself back on and off.  Not good!

Am I doing things right?  Any tips?

I think you have it set up right.  Normally the gearing in the servo prevents this.

How big of a SPDT are you using?  I'm using a micro-switch and it only needs a couple of grams to actuate it.

If the switch is at the far end of the arm there might be too much leverage happening.  If so, try repositioning the microswitch so it's closer to the servo.  Less leverage that way.

Let me know if this helps.

Yep that worked correctly.  Everything is set up and working.  Except when I solder all my wires to the DPDT switch.  No matter what I do, the soldering becomes unstuck and I lose connections.  I know I'm doing something wrong (I'm a complete novice at soldering), but I can't for the life of me work out what.  I've tried 'tinning' my soldering iron but the solder isn't sticking to that either.  Pulling my hair out here!
The tips on soldering irons will wear out.  There is a coating on 'em that eventually "burns" off.  As a temporary fix, take some sandpaper or a file, and sand off the "crud" on the tip.

This should allow you to tin the tip.  Then you can get the solder to melt and coat the tip of the iron.  Otherwise, the iron just won't transfer heat to what you're soldering.

Also, most people when they are learning to solder are scared of overheating things.  Consequently, they end up making 'cold solder joints" that fail.  Keep in mind that electronic components are designed to take a lot of heat for a short time.

Once you have the tip of the iron tinned, leave a small blob of solder on it to help the heat transfer.  The part you are soldering has to be hot enough to melt solder.  Ideally, soldering small pins like those on the toggle and micro switches should only require a second or two.  But they should be able to withstand 10 seconds of heat without damage.  Don't apply heat any longer than that.

Also, the pins may have oxidized, making soldering almost impossible.  Use the sandpaper or file and sand off any crud, making them shiny.

Also, you can get a small container of flux, and put a small dab of it on the pins before soldering to help remove any oxidization.  You should be using solder meant for electronics that is called "Rosin Core", but sometimes there isn't enough rosin or flux in the solder to remove a heavy coating of oxide.

I really should make a soldering 101 instructable, because it can be daunting for beginners, and I haven't seen any instructable that mention some of the things I've pointed out...

Hope this helps.

The arm shouldn't be coming back up for the second time or repeating, since it was turned off by itself.
It was the spring on the SPDT switch that was pushing it back.  Never mind, I managed to relocate my SPDT switch closer to centre of rotation of the arm and fixed the problem.
Cammer5 years ago
This is hilarious!  Is anyone making these for sale?  I'd love to give a couple away as gifts.
 That's sweet! I Want one, but I suck at sodering i'll mess it up :(
TheReaper5 years ago
Can i use an Ne555n timer instead if the NE555P one?
Yep, shouldn't be a problem!
If it wouldnt be too much trouble, could u post what it would like on a breadboard
Sure, check back in a day or two!
Thanks alot man, you seriously rule :D
I've added step 7 showing it breadboard.
Thanks alot! i cant thank you enough :D
Now make one that makes noise and instead of turning itself off it can always turn itself on. lol
The most Annoying Machine...
Completely Pointless, But Completely Awesome!
Toggleme5 years ago
What would be the effect of using a 0.15 uF capacitor? My local shop only had these...
Frivolous Engineering (author)  Toggleme5 years ago
It might work, but you may not get as much rotation as you need.
It won't hurt anything to try it out.

But I would recommend going with a modified servo.  No need for the control circuitry, much easier.
zapedy5 years ago
 What gauge of wire is being used
Frivolous Engineering (author)  zapedy5 years ago
I used some wire from a piece of telephone extension cord.  It's quite thin, around 24 gauge, I would think.

There isn't a lot of current so just about any wire will do.  Stranded wire is best, but solid will do in a pinch.
Jgray5895 years ago
Is there anyway someone can post a video on how to do the circuit board and wirring?
Frivolous Engineering (author)  Jgray5895 years ago
I didn't use a board, just soldered the components directly to the chip, and toggle switch.  daw123 (below) used a strip board and posted a graphic on how he wired it up.
daw123 Jgray5895 years ago
I can't post a video because I've already completed the build, however I can post the diagram for the circuit if you plan on using a stripboard.

Stripboard: http://upload.wikimedia.org/wikipedia/commons/thumb/f/f9/Stripboard.jpg/588px-Stripboard.jpg

Circuit diagram: http://i429.photobucket.com/albums/qq16/dawilson123/CircuitLayout-1.png

The completed circuit: http://i429.photobucket.com/albums/qq16/dawilson123/DSC03383.jpg

Items of note:

1. The circuit diagram is for the non-tracked side of the stripboard. Therefore if you are looking at the stripboard from the tracked side, everything is mirrored.

2. If your servo is rotating the wrong way, swap around the connections to pins 4 and 6 on the toggle switch.

3. Make sure you connect pin 1 on the circuit for the micro switch to the NC (normally closed) pin on the micro switch and pin 2 on the circuit to the common pin on the micro switch. I noticed on my micro switch that pins 2 and 3 were the opposite way round to Saskview's circuit schematic. The micro switch should have C, NC and NO stamped beside each pin; this corresponds to the common, normally closed and normally open pins.

4. Adjust the two micro potentiometers to get the correct degree of rotation on the servo both ways. The potentiometers have a common pin in the middle and a pin either side (three pins altogether). Make sure that you connect the common pin and either of the other two pins to the circuit; i.e. only two out of the three pins will be connected.

5. You can create a break in the track by very slowly drilling (I used a 3mm diameter drill bit) the tracked side of the stripboard. Centralise the drill bit in the hole where you want to create the break in the track and start drilling very slowly until you create a complete break. Do not drill completely through the stripboard or damage the tracks adjacent to the track you want to create the break in. i.e. You are producing a counter-sunk hole in the board, where you want the break in the track.

6. Make sure that when you solder the various components and wires to the tracked side of the stripboard, none of the solder crosses (makes a connection)between adjacent tracks.

7. Only solder on the tracked side of the stripboard.

That is all I can think of and I hope this post helps.
Frivolous Engineering (author)  daw1235 years ago
Well Done!  Thanks daw123
You're welcome.

I've realised that the link in my second comment was broken. The below amended schematic includes the pictures and the connections of the main components on the stripboard.

I thought DPDT means "Double Pole Double Throw"?

It does.  A DPDT could also be called an ON/ON switch. There really is no "off" on this type of switch.  Your just selecting between two circuits.  One side is doing one thing and the other side another.  Switch polarity (a crossover) on the other side of the switch and the motor runs in reverse. 

Here's how I wired mine up.  I replaced the old image because it didn't show the rocker switch.  I use the rocker switch to cut power on retraction via the arm hitting it on the way down.   Hope yours works out.  Look forward to seeing it.
Diclonius5 years ago
 congrats on being featured on funnyjunk 
Thanks for point that out.  It turns out that it's a pirated version of the video, @$&%#!!!!!!

Not the first time it happened, or the last.  "The Sun" newspaper in England also put up a ripped off version of the video.  And hasn't taken it down even after I contacted them.  CollegeHumor posted a rip, but did remove it.
tydarby5 years ago

This has been SO much fun to build.  I wanted to share my design.  I built mine on a 1/4" inch thick poplar base with1/8" mahogany sides and top.   I didn't use any resistors or control boards or anything like that.  Just 6 easy wires.

Futaba standard servo*
3 AAA's batteries
1 rocker switch

This is a great project.  I can't wait to build another with my nephew. Enjoy. I hope you like it.  Please feel free to contact me with any questions or suggestions.

Some notes:
1.  I mod'd the servo in two easy steps.  Just remove the plastic piece off that gear so it can spin 360 degrees.  I removed the white wire and soldered the black and red directly to the base of the servo.
2. I put the servo on the base of the box.  I've seem most mounted on the lid under the servo.
3. The retraction of the "arm" engages the rocker switch and kills the power.
4. I only used 3 AAA's instead of 4 AA's.  Seems to work fine.  Saves space.
5. The box sits in the poplar base over 4 "Studs" at the each corner and brass screw hold the box to the base.  See the last pic.

Thanks .

Frivolous Engineering (author)  tydarby5 years ago
Thanks for the great comment and info!