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Will a 20w MR16 bulb powered by a 12v battery melt a cheap plastic flashlight?

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Will a 20w MR16 bulb powered by a 12v battery melt a cheap plastic flashlight?

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Old 01-02-08, 11:26 PM
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Will a 20w MR16 bulb powered by a 12v battery melt a cheap plastic flashlight?

It fits. All I need is a battery.

Funny, on the roadie forum I've sometimes jokingly asked "will my bike burst into flames if I do this?"

It seems here, that question might be for real.
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Old 01-03-08, 03:38 AM
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I'm gonna say yes...

I've got one in a schedule 40 1.5" PVC coupler and it's taken a few months but even it's starting to shrink. I think what's getting it is when I leave it on to discharge the battery, but those are pretty tough so I figured it would have handled it.

If your idea of a cheap plastic flashlight is the same as mine, I'd give it a week.
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Old 01-03-08, 07:33 AM
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Yes, and probably VERY quickly. My 15W in a waterproof nylon shell gets too hot to touch the casing in under 5 minutes unless it's below freezing out.
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Old 01-09-08, 06:57 PM
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I would be surprised if it lasted a ride. Putting it in EMT conduit would be my first consideration, but I'm an electrician who can get this stuff easily. Schedule 40 PVC is better than a cheap flashlight and is probably less expensive. I elected to use a head from an egress light for my bike, and it works quite well.
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Old 01-09-08, 07:46 PM
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Originally Posted by lectraplayer
elected to use a head from an egress light for my bike, and it works quite well.
Are you talking about aircraft emergency exit lights? I knew I should have snagged one when I was in the Air Force
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Old 01-09-08, 07:55 PM
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Drill lots of holes in the plastic and only turn it on when you are moving. Should help. I've had a rubber truck headlight mounted on my bike start to melt when I was testing battery life one summer day but that was a 100 watt light.
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Old 01-09-08, 09:32 PM
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I'm actually planning a different course of action. First of all, I went out and bought two D-cell batteries in order to use the cheap plastic flashlight for it's original purpose - a flashlight.

Besides stock garden or kitchen lights or the cheap car lights, what other options do I have for a homebrew light housing?
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Old 01-16-08, 07:20 PM
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Originally posted by MrCjolsen
Are you talking about aircraft emergency exit lights? I knew I should have snagged one when I was in the Air Force
That will probably work just as well, but the egress light I used was designed for a building. Be sure your light has a swiveling head and casts a beam. Some don't cast beams and some don't have swiveling heads. Be sure to test-burn the lamp before mounting it on the bike to avoid any lighting surprises.

Getting these may sometimes be accomplished by "dumpster diving" a construction site, especially remodels. Be sure you ask the general contractor first, though. This can get hazardous without a little assistance. Some electricians would also be glad to snag one for you that they demo too!

For a housing to build your headlight around, water pipe would be a good starting point. You can almost always find something to fashion into whatever kind of enclosure you need with a little modification.

Also, consider using LED's for the guts of your light. That may help blow your options wide open, and give you something to make a decision off of. If you can do more than just plug and screw wires together, nothing can stop you. :evil:

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Old 01-22-08, 01:36 AM
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Originally Posted by MrCjolsen
Besides stock garden or kitchen lights or the cheap car lights, what other options do I have for a homebrew light housing?
For MR16? Here`s a thread about using a $12 submirsible pondlight from Harbor Freight to house them. I built one from the same thread for my commuter and I`m working on a dual housing model now for a hi-low setup on my mtb. It`s an easy way to go about it, works good, and looks clean.
https://forums.mtbr.com/showthread.php?t=245737
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Old 01-22-08, 02:00 AM
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Originally Posted by MrCjolsen
Besides stock garden or kitchen lights or the cheap car lights, what other options do I have for a homebrew light housing?
I really love my old 20w MR11 tennis ball light for its simplicity.

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Old 01-22-08, 03:55 AM
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Now that, is ingenuity...

How long did you run that in the ball?
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Old 01-22-08, 12:56 PM
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Maybe 20-30 rides in all weather...I got sick of the big SLA battery so last year I switched to LEDs for better run times and less weight, now running a dynamo system.

It lives on though, use it as a light in the shed here. The ball doesn't get that hot, nice and warm. Its been run stationary for two hours at the odd BBQ too so the rubber holds up to the heat well.

I have a 12w spot that I used to use on the rides too ... thats the beauty of it, so cheap you can build a few different heads, and instant head changes.
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