Weatherproof cable/housing junction for 1" square aluminum tubing

[MitchK]

Hello,

I'm planning some LED lights, using square aluminum tubing, borrowing ideas from nightrider and others.

The one thing I'm still working out is the cable/housing junction.

Weatherproofness is a key consideration (I commute rain or shine), so I'm reluctant to use an RCA or similar type of quick-disconnect approach.

The male/female weatherproof connectors I've found are too pricey, too big to work with inside 1" square tubing, or both.

Ideally, I'd like a simple rubber (or similar) strain relief plug thing like this:

http://www.connectworld.net/iscmc/b_relief.html

But I can't find where to buy it.

So my default solution will be to use a rubber grommet (reinforced with silicone sealant) and pass the electrical cable right into the housing.

Any thoughts on that solution? Any other ideas?

I'll be ordering most electronic bits from digikey.com, so the lazy person in me is really looking for suggestions of digikey part numbers for things (other than grommets) which would work.

Thanks,
Mitch

 

[znomit]

I use rubber grommits plugged with silicon. Work fine. Tie a knot in the cable or a really tight cable tie inside the housing so it cant be pulled through.
Position the hole out of direct spray/rain, and dont have anything pulling hard on the cable.

BTW...after building my MTB light I forgot to plug the grommit with silicon, went for a ride in the rain and the light got very wet inside. Rinsed it out with water, and ran it for several hours to dry before sealing up properly. Its still working fine. I think my lenses have a good seal over the LEDs.

 

[1 what]

Ditto the above post.

"I use rubber grommits plugged with silicon. Work fine. Tie a knot in the cable or a really tight cable tie inside the housing so it cant be pulled through.
Position the hole out of direct spray/rain, and dont have anything pulling hard on the cable."

The only thing I do differently is to epoxy the cable/grommit/case junctions and then rain/mud (no snow where I live) has no chance. I also use heat shrink tube over the cable where it goes through the grommet to give it some extra support. I've never had to replace a LED so have not had to undo my handiwork. If I did I'd simply re-drill the original hole.

Could we see a photo of the finished produst please....a square profile - I like the sound of that.

 

[MitchK]

Thanks to both of you. I like the idea of additional reinforcement/epoxy (nothing succeeds like excess, especially when the weight/cost/aesthetics penalty is insignificant).

I'll definitely upload some photos of the finished product. My goal is to have them done before the current dark commuting period (say by mid-January) so I can give them a good workout under real-world conditions.

Here's the design that originally caught my attention and transformed my view of generator lighting:

http://joegross.net/2007/08/14/schmidt-hub-dual-cree-xr-e-led-light/

After doing more research I discovered Martin's wonderful contributions that he has shared with CPF. For starters I'll be building his 2-LED-in series high-power circuit for a generator headlight.

Here's the other page that gave me ideas. I believe the writer contributes to CPF under the name "nightrider". He also contributes to mtbr.com under the name "achesalot":

http://myfwyc.org/bikeled/DIY_LED_Bike_Lighting_Guide.html

Overall I'll be building two 2-LED headlights. One battery-powered, one generator powered, both in square 1" aluminum tubing with Cree XR-E's and Ledil optics. I'm hoping to do a writeup when all is said and done, or at least photos of the finished product.