How to buy or make a shock proof enclosure?

Discussion in 'General Electronics Chat' started by ionymous, Dec 8, 2009.

  1. ionymous

    Thread Starter New Member

    Dec 8, 2009
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    I want put a small microcontroller, digital compass pcb, and batteries in a project enclosure, and then attach it to my mountain bike.
    I will likely mount it within the bike frame's main triangle on the tube that the seat post slides into.

    I ride pretty aggressively on the trails. Some hopping, drops, and I take some falls occasionally.

    How can I protect the electronics?
    Are there cases that are made for this kind of abuse? Probably too expensive. Can I make my own?
    Are there some kind of rubberized standoffs? Can I make my own?

    What other ideas do you have?

    Thanks for any help
    Ion
     
  2. KMoffett

    AAC Fanatic!

    Dec 19, 2007
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    Strap it to your body. You're less likely to abuse it than the bike...even in rough terrain. In a foam lined "Pelican" case: http://www.pelican.com/

    Seriously!

    Ken
     
  3. ionymous

    Thread Starter New Member

    Dec 8, 2009
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    Thanks. Strapping it to myself IS a good idea for removing shock.
    I'd still like a bike-attached solution though.

    Are there any circuit board mounting tricks for this?
     
  4. KMoffett

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    Free floating, inside foam padding, inside a hard case. Is it just a datalogger, so you don't have to see anything?

    Ken
     
  5. BMorse

    Senior Member

    Sep 26, 2009
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    Radio Shack use to sell small project enclosures that were made of some durable plastic, you could get one of those and still do what Ken suggested and pad the PCB with foam on all sides..... How big is the circuit board that you need an enclosure for?

    I would not mount the enclosure right onto the frame, try to use some small bungee cords or something to support it from the 4 corners of the enclosure (if you have to, use some big rubber bands) these will act as shock absorbers and keep your enclosure from experiencing direct shock.....
     
  6. ionymous

    Thread Starter New Member

    Dec 8, 2009
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    Yes... no external interface aside from a power switch and a button or two possibly. No display.

    You mean don't even use standoffs? Just wrap or sandwich it in foam, inside the enclosure? I'm not questioning the idea... just reiterating it for clarity.
     
  7. KMoffett

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    I've never seen a Radio Shack enclosure that would stand up to the kind of abuse we're talking about...on the bike...or even on the body, if they take a tumble. We use the Pelican cases because they're tough and waterproof in field use..

    Ken
     
  8. ionymous

    Thread Starter New Member

    Dec 8, 2009
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    Well.. let's just say the general size and shape of the enclosure would by similar to a Wiimote. Maybe a touch wider and deeper... but probably about as long.
    I actually don't have my parts yet. But that's what I'm expecting.
     
  9. BMorse

    Senior Member

    Sep 26, 2009
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    Well, that is why I suggested suspending it with rubber bands or bungee cords so it would not take any direct shock, by they are tough enough to handle some abuse.... I have used them in many applications where they have taken quite an abuse and still saves the electronics (I mean, what can you expect for something that costs $2.99? :D)
     
  10. KMoffett

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    Add 1" of soft foam to all sides of the datalogger dimensions for the internal dimensions of the case.

    Ken
     
  11. KMoffett

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    I was thinking of not only the vibration and bouncing while they ride, but also when they get dumped. :eek:

    Ken ;)
     
  12. davebee

    Well-Known Member

    Oct 22, 2008
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    Don't use a battery holder that holds the batteries in place with springs, or big bumps will restart your controller!

    You can buy NiMH cells with solder tabs; four cells will run 5 volt logic directly.
     
  13. ionymous

    Thread Starter New Member

    Dec 8, 2009
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    Implying that a spring may momentarily come away from a battery?
    If that's true, then this advice is priceless!
    I could imagine debugging that for a long time! Thanks.
     
  14. davebee

    Well-Known Member

    Oct 22, 2008
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    Yes, exactly, and it doesn't take much of a bump, either, because batteries are pretty dense.

    I learned this through the experience of making four versions of battery-powered bicycle GPS trip loggers.
     
  15. ionymous

    Thread Starter New Member

    Dec 8, 2009
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    I might still try my luck with spring style battery holder, but take care to keep the batteries from moving. Double stick tape and/or rubberbands.

    But I will know to be suspicious if I see power cut out / reset problems. Thanks!
     
  16. ionymous

    Thread Starter New Member

    Dec 8, 2009
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    I've looked through the pelican cases but didn't find one that stood out as perfect. The i1030 looks like it might be my best bet so far. It is designed for carrying an iPod.

    If there was a rugged case designed for carrying a Wiimote, that would probably be perfect. But of course, no company would make such a case.

    I'm trying to brainstorm... what is the size and shape of a wiimote, but IS something a company would make a rugged case for?

    Maybe some kind of sensitive measuring tool? Calipers or micrometers are too flat. Hmm...

    Any ideas?
     
  17. KMoffett

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    Generally, ones like that are designed primarily to be waterproof. So, when your canoe tips over it will float and be OK. I would get you logger design down...then select a case.

    Ken
     
  18. KMoffett

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    Generally, ones like that are designed primarily to be waterproof. So, when your canoe tips over it will float and be OK. I would get you logger design down...plus padding...then select a case.

    Ken
     
  19. shortbus

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    Sep 30, 2009
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    Why not make your own?

    Go to Home Depot or Lowe's to the plumbing dept. Check to see what size PVC pie the remote will fit into with a 1/2 inch or so per side clearance. Get a piece of that pipe and a glue on cap for bottom. For the top get a glue on threaded adapter and a threaded cap that matches.

    Glue the parts together, except for the threaded cap. Wrap your remote with enough "Bubble Wrap" to fit snuggly into the PVC tube and screw on the cap.

    Go to the bike shop and find a water bottle rack to fit the PVC tube and attach rack to your bike frame.

    If you look at phone company vans(at least in my area) the have a large version of this mounted on the roof. To hold tools.

    Fishermen also do this to make rod holder tubes for traveling.

    Cary
     
  20. KMoffett

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    I like that. I was thinking from a professional, big budget point of view. :rolleyes: PVC pipe and fittings are an excellent choice.

    Ken
     
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