Cheap DIY tilt switches are great in a pinch

diy-cheap-tilt-switch

[fjordcarver] was looking for some mercury-free tilt switches that wouldn’t break the bank and that were easy to build. He also wanted something cheap, so instead of buying some tilt switches he devised his own that fit all of the criteria he set out. Now, these switches are not your typical fare, and they’re not small either. They are however, cheap, effective, and easy to manipulate/repair.

He picked up a package of metallic craft beads at the store and emptied out two bottles, saving one set of beads that happened to be conductive, i.e. not coated with paint or coloring. The beads were split between two jars, which were then sealed with corks that had a pair of straightened paperclips inserted through them. The bottles were oriented facing away from one another, then attached together with a piece of house wire. One of the leads from each jar was attached to this common wire, while the others were extended with hook up wire for use in the circuit he was building. Pictures definitely explain the mechanism far better than words can, so be sure to check out his tutorial to get a better look at them.

While they might look a bit rough, he says they work great, so give them a try if you have the need.

Comments

  1. Roy van Rijn says:

    Nice idea!

    An even smaller version could IMHO easily be made with a single small metal ball per tube. If you have a small barrel in which the ball tightly fits. Even using one tube with wires on both ends..?

    • Victor says:

      That’s more corrosion / dust sensitive than this solution, as contact surface is a lot larger with a lot of small balls.
      I’ve seen the solution you propose, but it used gold plated contacts and a gold plated ball.

      • p0e says:

        Kind of like saying a Honda Accord isn’t a good car to buy because your home made car has a nicer cup holder.

        No real reason you couldn’t assemble the single ball and tube in a relatively clean environment then seal it like every ball&tube tilt switch manufacture does.

        Even better… just buy a tilt switch for a buck. Link to one below.

      • Tony says:

        The other advantage of the little balls is there’s more change for them to knock any surface corrosion off themselves as the roll around (it’s a ball tumbler!).

        It is nice to see an actual ‘made from random crap’ hack here for once.

    • Steve says:

      One could use steel shot used for duck hunting as the balls too. alot cheaper though probably need to get a larger quantity. You may be able to get some from a local gun shop though for cheap since you would just need a hand full.

  2. max says:

    well, thats fault-prone, ugly and dangerous… i love it! :)

  3. cgimark says:

    BB ammo and an old ball point pen case works well. Seal ends with hot melt glue.

  4. F4radayDefcon414 says:

    I wonder how much current could run through these before the balls melt. I like vow V controls anyways, but where I use them they get beat up a lot & need to be fused with FA fuses. Neat idea!

    I have a solution: copper BBs (most are copper plated steel). 1000 for probably less than the craft store beads (those places are so expensive!), but the containers and contacts would have to be larger

  5. brad says:

    obviously the price would increase with the use of a ferro-fluid, but wouldn’t it be more fool-proof?

  6. Sven says:

    Could this really beat the price of mercury tilt switches on ebay? I just ordered 10 for 5 USD total.

  7. BB ammunition works great (if you have it), but you can also use copper filings. The sharp edges helped reduce oxide buildup. You can get scrap copper from copper wire or copper pipe. Aluminum filings might also work.

    No need to go shopping for appropriately sized metallic beads, and then to test them and sort them by electrical conductivity.

  8. fioa says:

    that could be used to detonate an IED :D

  9. anyone says:

    why is everyone such a mercury pansy now a days?

    mercury switches are sealed and if they do happen to break, unless you’re an idiot about it, nothing is going to happen to you.

    • F4radayDefcon414 says:

      I beg to differ a little bit. Sure, mercury pansies are the same people that force silly enviro and safety rules (I’m talking about evacuating an office floor if some Hg fluorescent tubes break, like in Germany(?))

      When mercury contactors go bad, they explode.

      Costs us $25k and three days of downtime every time one blew up at work, despite being in a sealed cabinet that nobody ever goes into …but you know, not enough money in the budget to replace them with non-Hg contactors (Under $150 each).

    • Justin says:

      Say it does break, we know that you won’t eat the tasty shiny blob, but how do you properly dispose of it so that it doesn’t contaminate where ever it ends up?

      Also because mercury is forever, you are not. What ever project is built with it will eventually get scrapped and not necessarily properly recycled.

      • Sven says:

        The recommended layman’s method for disposing of spilled but visible mercury blobs is to amalgamate it with tin, most easily any tin based solder. Just feed solder into the blob until all of it has hardened.

        If spilled into cracks in floors or similar, it is recommended to contact some kind of poison information service or similar, since it could potentially leak mercury vapor over several years.

    • hospadar says:

      Who cares what happens to you, we are making new babies all the time. Making new Great Lakes that aren’t polluted with mercury is a lot harder. It takes very little mercury to poison a huge amount of water.

      • anyone says:

        well, i care about me and don’t really give a fuck about your babies.

        i’ll make sure my babies will be smart enough to either avoid drinking mercury or be able to detect and purify the water.

        if you’re that concerned about your babies future, i also hope you aren’t reading this website on a monitor, or using the internet that has PVC insoluation for the wires, or is powered by fossil fuel.

    • Bob says:

      If you are concerned about the long term, you know that your switch with mercury comes from a batch of thousands, which account for alot of mercury. Maybe your switches won’t break, but you can’t tell what will happen to all of the switches that came out with them. So, some people just avoid all mercury because: 1) they can, 2) they care.

      If you don’t care, you’ll never agree. You probably won’t even understand why someone would care. Hence, it’s stupid to care.

      • anyone says:

        “caring” is not a binary process.

        i would love it if the gov. put out a statement for their recommended maximum level of carbon exposure.

        then see all of the followers who vow to cut all carbon out of their life completely.

  10. I think mercury pansies are a result of “Alice in Wonderland” and the “Mad Hatter”… ;-)

  11. oodain says:

    or the knowledge that its function in this case ca be achieved to same or similar effect without virtually any hazards at all.

  12. Ian says:

    Great! Al Qaeda everywhere can now build safer, lead-free bombs using more of their junk!

  13. Velifer says:

    Now extend this with Wood’s metal so you have a thermally sensitive tilt switch. It turns off or on only when above 70ºC, so it makes a thermally latching position-sensitive switch!

  14. Depending on the decorative bead package price, it can be even cheaper if you buy plain metal balls. You can get 500 1/16″ carbon steel bearing balls for less than $5 before shipping from McMaster-Carr. You could experiment with different sizes (or even combinations) for the best flow/lowest angle of repose.

    (I was looking at 96455k71 on the mcmaster.com website.)

  15. Alan says:

    Nip little bits of solder onto your solder block; a fire brick, carbon block, even a piece of wood will work.

    Hit them with a torch and when they ball up, tip the block up steeply, spilling them into a jar of water.

    The result is nice little conductive beads of metal. You can control the size fairly easily, though if you go too big the blobs surface tension cannot hold itself in a spherical shape.

  16. Agent24 says:

    Cool idea but I think I’ll stick with real mercury tilt switches.

    Not that I’ve ever actually needed more than the one I already have.

    But eBay has heaps of different types, all very interesting, and no doubt even harder to duplicate.

    Now, if only I can find a good source for mercury-arc rectifiers….

  17. jimbob says:

    when i have a simple problem easily taken care of by a reliable, cheap, off the shelf solution, i come to HACK A DAY, where i know i can find an ugly, more expensive, and unreliable solution.

    usually involving an arduino.

    • Garbz says:

      Oh I’m sorry. You must be looking for a advertisement, online store, or vendor website.

      This is HACK-a-day. A place where you learn to build stuff out of shit you have lying around.

      Now next time you get bored waiting for a delivery of high quality manufactured parts please go and provide a different site the displeasure of having you around.

      • jimbob says:

        congratulations, you have fully embraced the HAD mentality.

        your arduino brain implant will be arriving shortly in the mail. please make sure you have a rusty spoon and a roll of 24 gauge wire to install it.

  18. hatenull says:

    Having been hit by and still exposed to the dangers of IEDs I don’t appreciate the sarcasm about them. As for tilt switches being used for such an application, it is almost unheard of, at least in Afghanistan. Too much could go wrong with the emplacer and cause unintended detonation. The guys that build those things are rather smart, the guys using them are 99% likely to be illiterate, stone-aged, unwashed fanatics with enough training to dig a hole and hide the wires.

    Great little tilt sensor, it does its job, and meets the creator’s requirements, exactly what it needs to be.

    • Whatnot says:

      Since IED is not the general term it doesn’t necessarily mean iraq/afghanistan, people like the unibomber for instance also made ‘IED’, and in WWII soldiers often made IED for combat purposes.
      Didn’t saving private ryan also have the guys make IED? And I once read an army soldiers basic manual and in it they also advise how to make homebrew things to stop tanks and such.

  19. DudeGuy says:

    This is genius.

  20. Stefan says:

    A nintendo nunchuck clone is like 4 euro now and contains a 3 way accelerometer with i2c. this only makes sense for analog circuits in my opinion

  21. fjordcarver says:

    Hey cool my tilt sensor is on hack a day. Glad to see people like and hate it. It works. Good enough for me. How come the maker never knows this stuff. Cheers, I hope some of my other crap filters through here, really exciting to see it, although next time I should be told…wink wink, nudge nudge…..

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