Simplest most useless machine

[Brett] posted about his most useless machine build. His project gives us a chance to massacre the language in the title because it uses the lowest parts count we’ve see with these machines. The logic is controlled by our friend, the 555 timer. Add to that just one servo motor, two switches, three resistors, two caps, a diode, and a battery pack and you’re in business. The hardest part to find locally is the servo but check at a hobby/RC store. If you don’t have to put in a parts order this can be your next impulse project.


  1. jbot says:

    I’m inspired! I think I’ll make one with a pair of Arduinos!

  2. macegr says:

    I think I could make one that’s a lot simpler. Ingredients: (1) switch, (1) rubber band.

  3. pxd says:

    why have i a feeling that ive seen this before somewhere… several times too ;|

  4. malikaii says:

    the best useless machine ever.

  5. idbar says:

    The music gives a sense of usefulness for some reason, it makes… uhm.. happier? Hehehe

  6. Dev says:

    Love it! I will have to build one for my 18-month old niece!

  7. poot says:

    @pwd…because it was posted here a few months ago ..LOL…I guess the poster couldn’t search first to check.

  8. damntech says:

    Yeah, hackaday posts one of these at least once a year.

  9. Jes1510 says:

    Hehe, I love it! Very clever and good presentation. Great work!

  10. Mic says:

    The wooden box is the nicest part.

  11. Gene says:

    So what if something similar was posted here before. This one’s better. I’m making one.

  12. Penske says:

    Now we just need to build the biggest most useless machine ever.

  13. taylor says:

    haha, I’ve seen the others posted on here, but this one is by far the nicest looking!
    I really should build one of these… I’ve got all this stuff lying around!

  14. DarwinSurvivor says:

    I’m with macegr, a simple dc motor, a switch and a rubber band (or gravity) should make this even cheeper :D

  15. Brett says:

    Thanks for featuring my ‘ible!

    And thanx fer all the great comments, folks!

  16. DimensionX says:


    “The only design I could find uses a 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!” –

    So there is a difference….just…not much of one.

    This is neat though, I’ve been thinking of building one to sit on my desk but it would distract me from work quite a lot.


  17. sarsface says:

    Jesus, this is the 3rd or 4th one of these I’ve seen on here.

  18. AnthonyDi says:

    I like it! I’m not sure if I like the acrylic one better because it holds the door open.

    It would be funny if it gave you the finger after it switched it back.

  19. sol says:

    I love it. Never seen these before and it’s blowing my mind.

  20. bencoder says:

    I’m pretty sure I can come up with a simpler one, no servos, no 555. Using this, very simple circuit:

    The arm holds the push-to-break switch on the left at the bottom of its journey. When the switch at the top is changed, the arm rotates, releasing the push to break, hits the switch which changes the direction of the motor, until the arm rests on the ptb switch again, turning it off.

    I can’t be bothered to build this though so if anyone else does, let me know.

  21. Paul says:

    clicking on that link gave me malware, I had to restore my system. Chromium has the page flagged as containing elements from the website “”

    Please remove the link, its dangerous.

  22. bencoder says:

    which link? mine? it’s just a jpg.

  23. Paul says:

    No not yours (sorry about my clarity), the instructibles page link brought up a chrome warning, I passed it and got a nasty spot of malware. Seems that instructibles has a malware advertiser or something that randomly appears…

    …offending website is “”

  24. latrokles says:

    reminds me of Claude Shannon’s own useless machine:

  25. Chris says:


    Good idea, I hadnt thought of that method to make it even simpler. However this one still deserves much credit for being such a fantastic implementation in a nice box.

  26. ~ says:

    idk guys, lowest parts count? i could make one with just wire(7 pieces, we’ll count it as 1), 1 DPDT toggle switch, 1 DC motor (plus gearbox) , 1 battery, and 1 normally closed pushbutton switch. LOOK MA, NO SEMICONDUCTORS!!

  27. smilr says:

    I was going to say – what exactly is the point of adding a 555 timer? All the up/down logic could be hardwired into the switches.

    And @Penske:

    I envision something with pneumatics or hydraulics, and one of those giant electrical breaker switches:
    such as

  28. tim says:

    i do not understand how this work,
    where is the arduino ????

  29. Andy k says:

    haha, this made me laugh

  30. Zymastorik says:

    Waste of space. I mean seriously ou guys, how many of these retarded boxes do we need to see? We get it, it’s useless and easy to build.

    Just leave the space blank next time instead of posting the same crap over and over and over and over and over… suprised it isn’t built of Legos and using an Arduino somehow. sigh

    Has the hacking community really gone this half-baked, or do I just need to find another board to frequent? Jeez guys let’s pull it together, you’re not doing much to continue your predecessors legacy.

  31. markii says:

    haha, this is pretty cool even though it is useless. most useless things are actually pretty cool.
    i love it in it’s total stupidity! :)

  32. HandyBob says:

    I said it on instructables and I’ll say it again.
    This needs audio. Some funny sentences every time it opens.

  33. Chris says:

    I think “Oi!” would be the perfect sound every time it turns on!

  34. HandyBob says:

    I was thinking about a different sentence every time.
    “Hands off”
    “Don’t do that”
    And if you push the switch a couple of times in a row:
    “what do you think you’re doing”
    And then the lid would lock itself for a while

    So useless, so much fun :-)

  35. Stu says:

    @bencoder – looks right, there’s absolutely no need for any semiconductors here.
    Although the idea of the 555 timer chip is good for learning electronics in general, I think its important to keep some perspective on when to employ mechanics to reduce circuit complexity, and your schematic is a great example.
    One point of note, am I right in saying that one of your batteries should be wired in reverse to make the dc motor move backwards? I’m not sure your schematic makes that clear.
    Gearboxes though are a pain to source if you want a new one, its best to rip up an old RC toy but then you usually end up with a gearbox of arbitrary ratio.
    Its so difficult to source the perfect gearbox without making your own gears and shafts on both a CNC mill and lathe, or something. And if you do find one, its for industry, and costs a small fortune.
    And therein lies some advantages of a servo and microcontroller because you can control the speeds yourself!
    Great little project, the wooden box helps a lot because if you hadn’t seen one before, like I hadn’t, its all that more amusing! :-)
    I’m seriously thinking of adding that one to my list of stuff to make, but it would get very boring very quickly unfortunately.

  36. BigD145 says:

    I prefer the older acrylic build because it has the two step process.

  37. asdf says:

    I’m thinking of an evil version that instead of flipping the switch itself keeps pointing a toy gun outside the box to force the operator to do it.

  38. jh says:

    heh… the most useless machine made TheRegister

  39. Frogz says:

    heh… the most useless machine made

  40. LMFAO!!! This is the best machine ever invented! I want to buy one

  41. louis says:

    I want to buy one

  42. Flaschenzug says:

    So cool :-D. Great work.
    I actually try to build a single useless machine (just one switch), but this is very cool.

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