IP64/65 Enclosure Design - Sheetmetal? Best Practices?
IP64/65 Enclosure Design - Sheetmetal? Best Practices?
(OP)
Hi folks, go easy - it's my 1st post :)
I'm in the process of designing several automotive-grade enclosures for power electronics (IP64-65 protection). My plan thus far is to do custom sheet metal, weld up as many edges as possible, and use gaskets on the lids and around all connectors.
Any thoughts? Recommendations for best practices, alternatives to sheet metal (considering prototype volumes only), etc? Any good resources out there?
Thanks in advance for your suggestions!
I'm in the process of designing several automotive-grade enclosures for power electronics (IP64-65 protection). My plan thus far is to do custom sheet metal, weld up as many edges as possible, and use gaskets on the lids and around all connectors.
Any thoughts? Recommendations for best practices, alternatives to sheet metal (considering prototype volumes only), etc? Any good resources out there?
Thanks in advance for your suggestions!






RE: IP64/65 Enclosure Design - Sheetmetal? Best Practices?
How big are your enclosures?
If they are small, machining from billet is a possibility. If production goes up, you can modify them into castings.
Plan on spending a lot of time figuring out your gaskets.
RE: IP64/65 Enclosure Design - Sheetmetal? Best Practices?
Keith Cress
kcress - http://www.flaminsystems.com
RE: IP64/65 Enclosure Design - Sheetmetal? Best Practices?
I'm doing various sizes, most are in the neighborhood of 5"x8"x20", one of them more like 8"x20"x40". I mentally ruled out billet already due to the size... pretty much anything that I can move to casting later sounds like it'll be horifically expensive in the prototype stage, and our production will ramp up very slowly (200-ish units in the first 2 years). Thanks for the heads up on the gaskets.
Thanks for the rec on BUD too, I'll take a look.
RE: IP64/65 Enclosure Design - Sheetmetal? Best Practices?
Keith Cress
kcress - http://www.flaminsystems.com
RE: IP64/65 Enclosure Design - Sheetmetal? Best Practices?
Standard, solid rubber o-rings will be hard to implement on a welded, sheet metal enclosure. O-rings require accurate mating surfaces. They would be possible if the housings were machined from billet, but the OP is correct about his dimensions being too big. O-rings also require a lot of contact force, probably not possible on a box with an acceptably small number of screws. Search Parker's website for information how much force it takes to compress an o-ring.
Whatever fills his gap will have to be resilient enough to account for sheet metal and welding tolerances. A thick enough piece of closed cell foam rubber will work, the first time. It will set upon assembly. Hollow rubber sections are an excellent possibility.
Rubber suppliers can fabricate o-rings out of hollow rubber cord.
RE: IP64/65 Enclosure Design - Sheetmetal? Best Practices?
Thanks for the refresh info drawoh.
Keith Cress
kcress - http://www.flaminsystems.com
RE: IP64/65 Enclosure Design - Sheetmetal? Best Practices?
I have used them to clamp optics. They allow me to design a controlled preload for an expensive piece of glass. They are flexible enough to function through significant temperature changes.
In other words, I have crunched the numbers.
RE: IP64/65 Enclosure Design - Sheetmetal? Best Practices?
Sure enough it's tightly constrained inside a groove and the cover has a matching lip that seats down inside the groove onto the o-ring - all pretty high precision.
Keith Cress
kcress - http://www.flaminsystems.com
RE: IP64/65 Enclosure Design - Sheetmetal? Best Practices?
Is it a big casting or a little casting?
Little castings are more accurate than big castings, and the lids probably are more rigid. You can add complex gussets to make them more rigid. You can also make the O-ring fatter, which makes it squishier.
Larger IP65 enclusures use hollow gaskets.
RE: IP64/65 Enclosure Design - Sheetmetal? Best Practices?
"Art without engineering is dreaming; Engineering without art is calculating."
Have you read FAQ731-376: Eng-Tips.com Forum Policies to make the best use of these Forums?
RE: IP64/65 Enclosure Design - Sheetmetal? Best Practices?
http://www.budind.com/pdf/hb1334.pdf
It's actually ABS and not very big. 7"x4".
Keith Cress
kcress - http://www.flaminsystems.com
RE: IP64/65 Enclosure Design - Sheetmetal? Best Practices?
RE: IP64/65 Enclosure Design - Sheetmetal? Best Practices?
http://www.mcmaster.com/#catalog/115/3506/=19qsjb
RE: IP64/65 Enclosure Design - Sheetmetal? Best Practices?
htt
RE: IP64/65 Enclosure Design - Sheetmetal? Best Practices?
You can also get rubber vendors to cut gaskets from closed cell foam rubber sheet. This is very cheap, and the sheet can be self-adhesive.
As I noted above, the foam rubber sets upon assembly. If the device is not taken apart, this does not matter. If it is opened and closed regularly, I would recommend not using this.