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Old 03-17-07, 11:32 AM   #1
infernobutterfl
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DIY bike light - problem: casing too hot?

I recently made a DIY light system that uses a 14.4 v nimh 5000 amh battery to power a mr16 20 (or 35 watts if i needed it) for my bike system.

As I was testing how long the batteries lasted, I accidently touched the light casing, which ended up with me burning my hand. Those of you who made your own light set, do you have this problem as well? those of you who has a HID, is this a problem?


My casing is a metal casing, from optronics.
link: http://jcwhitney.com/autoparts/Produ...010204/c-10101

I don't if there is a way to avoid the heat problem. As I am biking, I just don't want to accidently touch the llight and burn myself. (The light gets hot enough to boil water... O_o)

Any tips would be great guys.
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Old 03-17-07, 11:44 AM   #2
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Light bulbs do get hot as a result of 'burning' electricity.
Halogen are the hottest I know of so take care with them
if that's what you used.
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Old 03-17-07, 12:25 PM   #3
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My 50 watt mr16 home made metal casing light will boil water right off it. I had to paint it with heat paint.
It can melt plastic easy.

HID lights put out more light with less wattage. My 16 watt HID is as bright as a 65 watt halogen light. But it's only 16 watts so it is not as hot. It's about the same heat as a 16 watt halogen light. It won't be as hot as your 20w bulb. I don't think I can burn my hand on the housing, not sure. The front of the bulb is pretty hot. I don't know if I can burn my finger on the bulb, but it feels like it.
The HID housing does get hot but my HID is not supposed to be operated without air moving over it anyway.

Most powerful bike lights say not to operate them standing still, and get hot enough to hurt you.
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Old 03-17-07, 01:58 PM   #4
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2manybikes knows best (*bows down*)

I have a question, though - I'm building a light and I just got a lensed flood MR-11. It is noticably smaller than the MR-16s but it has the same wattage and voltage specifications. What's the difference?
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Old 03-17-07, 02:14 PM   #5
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Quote:
Originally Posted by kill.cactus
2manybikes knows best (*bows down*)

I have a question, though - I'm building a light and I just got a lensed flood MR-11. It is noticably smaller than the MR-16s but it has the same wattage and voltage specifications. What's the difference?
It's just smaller in size. You can purchase 10-watt MR-11 bulbs which draw less current than 20, 35, or 50 watt bulbs allowing your battery to last longer.
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Old 03-17-07, 02:15 PM   #6
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Quote:
Originally Posted by kill.cactus
2manybikes knows best (*bows down*)

I have a question, though - I'm building a light and I just got a lensed flood MR-11. It is noticably smaller than the MR-16s but it has the same wattage and voltage specifications. What's the difference?

Hmm.. I dont know best, but I have played with Mr-11 and MR-16 bulbs. Watts for Watts, the Mr-16 is brighter, I dont know how much, but the beam pattern, spread and over all lumination is higher in an equally watt Mr-16 versus an Mr-11. (like wise, the mr-11 does not heat up as much.)

I started out with an Mr-11, but the light was weaker compared to the mr-16 with the same power draw and wattage. So i decided to switch to the mr-16.

with an mr-11 you can go down to 5 watts and up to at least 20. the mr-16 goes down to 20 watts (i think that is the lowest, but may be wrong)

hope this helps.
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Old 03-17-07, 02:18 PM   #7
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Sounds like you need to get a heat pump (computer modding to get the heat from the cpu) to get the heat from the light to your coffee mug...
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Old 03-17-07, 04:31 PM   #8
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I mount mine by glueing into tennis balls. Found tennis ball holders in the sports shop.
MR11 20w but I can still touch the ball to rotate it in its socket. Very simple to make and can swap out the tennis balls for different wattages and beams. Fav is 12w 7degree.

Yep metal holders will get pretty damn hot.


light1.jpg
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Old 03-17-07, 06:15 PM   #9
ax0n
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That looks like a fire waiting to happen once you start getting to 20 watts and above.
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Old 03-17-07, 10:04 PM   #10
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Quote:
Originally Posted by kill.cactus
2manybikes knows best
ow ow ow HOT !! ow HOT !! @#$%^&* ouch !

Quote:
Originally Posted by ax0n
That looks like a fire waiting to happen once you start getting to 20 watts and above
see above

Quote:
Originally Posted by Caspar_s
Sounds like you need to get a heat pump (computer modding to get the heat from the cpu) to get the heat from the light to your coffee mug...
see above ......

I think my 50 watt light might boil a cup of water, a drop of water on the housing is instantly vaporized, the inside of the housing gets to 350 f

Quote:
Originally Posted by znomit
I mount mine by glueing into tennis balls. Found tennis ball holders in the sports shop.
MR11 20w but I can still touch the ball to rotate it in its socket. Very simple to make and can swap out the tennis balls for different wattages and beams. Fav is 12w 7degree.
Great Idea !! don't know about 35 watts but 50 watts will set it on fire. My old 32 watt halogen Nightrider had a hard plastic housing and rubber o-rings around the bulbs. I don't think it would burn rubber.
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