Designing a waterproof/tight enclosure

Discussion in 'The Projects Forum' started by leonhart88, Jan 21, 2015.

  1. leonhart88

    Thread Starter Senior Member

    Feb 23, 2007
    118
    1
    Hi All,

    I'm working on a project that requires an IP66 rated enclosure. This device has to have several buttons and LED indicators. I don't have any experience with designing water tight enclosures so I thought I would pick everyone's brain here, while doing my own research in parallel.

    I would either be designing my own machined enclosure, or getting a off the shelf on. My main question is:

    If I make cutouts for LEDs, buttons or switches, what is the best way to add these while maintaining water tightness? I know there are some special IP-rated switches and LEDs, but they seem fairly expensive and are bulky. Is there a better way to do this (eg. heat staked or welded light guides, or mounting normal buttons/LEDs but with epoxy)? I am sure the examples I gave would work for IP66, but I'd like to find out the best practice for doing such a task.


    Thanks,
    Phil
     
  2. MrChips

    Moderator

    Oct 2, 2009
    12,423
    3,359
    Use a polycarbonate graphics overlay. You can use membrane switches or recessed buttons or snap dome buttons under the overlay.
     
  3. leonhart88

    Thread Starter Senior Member

    Feb 23, 2007
    118
    1
    Thanks for the reply MrChips. And I'm guessing the adhesive for mounting the membrane will prevent water ingress? I should be more clear in the number of buttons/indicators necessary. The design will only have 2 buttons...one push-button, one on/off power button (rocker switch), 2 indicating LEDs, and one infrared LED. The buttons and indicating LEDs can work with the membrane switch. The infrared LED will require a IR filter window of some sort that will be glued/epoxied in place.

    Is there a way to emulate a rocker switch with membrane buttons? Or should I just look for a IP66 rated switch and panel mount that.

    Do you also have any idea what costs are like for those membrane switch overlays? They seem to be mostly custom products (although purchasing IP66 rated switches and LED mounts are extremely expensive).

    I appreciate the help.

    Thanks,
    Phil
     
    Last edited: Jan 21, 2015
  4. ErnieM

    AAC Fanatic!

    Apr 24, 2011
    7,386
    1,605
    Anyway you do this it ain't gonna be cheap. My gut tells me to get all IP66 rated parts for the enclosure, switches, LEDs, and any connectors (something has to get into and out of the box, correct?) you may need.

    Then just follow the manufacturer's directions to mounting. Typically this will be a hole in the panel, and the device passing thru will come with a gasket.

    A while back when we had to put a product into a NEMA-4X box we found one with a transparent cover and left the indicators inside the box. In and out was provided via cable glands. (Glands are probably not a good choice for IP66.)
     
  5. sirch2

    Well-Known Member

    Jan 21, 2013
    1,008
    351
    Knowing what the actual application is might help? IP66 is dust and powerful water jet proof, will the item be dried out between wettings? How frequently will it be wetted? How dusty is the environment? Is it inside a car wash or bolted to a peir?
     
  6. leonhart88

    Thread Starter Senior Member

    Feb 23, 2007
    118
    1
    Hey guys,

    Thanks for all your replies. This will be a handheld device used in outdoor environments to test certain infrared receiver devices. It's a small handheld device with rechargable batteries inside, a microcontroller, and other relatively simple circuitry. The device pulses out data strings with the IR LED. No cabling required in or out of the unit, although we will have a USB port on the bottom (which we will need to find a rubber cover for).

    @ErnieM - as mentioned above, I won't need any cables running in or out of the device. The only concern I have about the IP-66 rated parts is that most of the ones I see on Digi-key are very bulky. IP-66 rated panel mount LEDs cost a whopping $15-20 on Digikey.

    @sirch2 - truthfully, the device could probably be IP65 and be suitable for outdoor use. The only water would be water from rain or puddles if it's dropped.

    I'll continue to do some research online. I really appreciate all the feedback.

    Thanks,
    Phil
     
  7. ErnieM

    AAC Fanatic!

    Apr 24, 2011
    7,386
    1,605
    Just so happens I recently got some USB bulkhead connectors, L-CON's ECF504-12BBS bought thru Newark at $13.44 each.

    Those particular connectors do not have a cover but it's something as a starting point for your search.
     
  8. leonhart88

    Thread Starter Senior Member

    Feb 23, 2007
    118
    1
    Thanks for the help @ErnieM. I've managed to find a nice looking IP67 rated part from Amphenol. Here it is:

    http://www.digikey.ca/product-searc...t=0&page=1&quantity=0&ptm=0&fid=0&pageSize=25

    I'm currently contacting various membrane switch/overlay manufacturers to see what the expected costs would be for that route. If those costs are way too expensive for the low volume we will initially be producing, then I'll look into using IP rated discrete buttons and perhaps IP rated light guides for the LED windows.
     
    ErnieM likes this.
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