# UK1200 dive light converted to hex Cree xre Q5



## spearsniper (May 27, 2008)

After looking at the range of dive lights available, and the associated high prices, I decided it was time to make myself one.
After many hours of investigation on the CPF, I came up with a plan.
LED's were the way to go - for burntime, and robustness.
Cree XRE Q5's were now cheaper, as the R2's have just come out, and from what I could determine, 6 could be run off a single maxflex.
I had an old UK1200 torch, which I thought was pretty decent - 12watt halogen bulb, and about 2 hours burntime from a set of disposable batteries. This was to become the donor case for the new light head.
I carved up a heatsink from a PC, drilled and tapped it, so that I could screw the stars on. The maxflex was glued to the heatsink with advesive heatsink tape.
Battery wise, I opted for 8 x 10,000ma/h NiMh D cells.

What I ended up with exceeded all expectations - both cost and performance wise.
The regulator is set to push 1 amp through the LED's, so the output is around 1200-1300lm.

Attached are some images:




















The UK1200 with it's 12 watt halogen bulb.




The LED lighthead - quite a difference.


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## DM51 (May 27, 2008)

Welcome to CPF, spearsniper - that is nice work and a great first post!

That looks like a very useful and impressive dive-light. A good idea to use an old host like that - it means the water-proofing problem is solved before you start.

One thing you will need to be careful about is heat build-up. Those LEDs will belt out a lot of it, despite the heat-sink you have incorporated, and the polycarbonate casing will act to some extent as a heat insulator, with heat building up inside.

This will probably be OK when the light is submerged, but I would be very careful about using it out of the water for more than just short bursts at a time.


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## toby_pra (May 27, 2008)

> DM51*Re: UK1200 dive light converted to hex Cree xre Q5*
> Welcome to CPF, spearsniper - that is nice work and a great first post!
> 
> That looks like a very useful and impressive dive-light. A good idea to use an old host like that - it means the water-proofing problem is solved before you start.
> ...


 
+1 :thumbsup: nothing more to say...very nice

and much more brightness :twothumbs


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## uluapoundr (May 27, 2008)

That's a great build. I have a couple UK1200 and was thinking about modding one of them. I was a little concerned about heat in that plastic housing. I wonder if those old Darryl Allen aluminum housing flashlights would be a better host. Thanks for sharing your build!


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## Gunner12 (May 27, 2008)

Nice mod!

And talk about stating with a bang!

The thermal properties of the polymer might prevent heat from being transfered to the water.

My guess would be around 700-1000 lumen out the front.

:welcome:


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## spearsniper (May 28, 2008)

Thanks for the heads up regarding heat build up in the casing. I have set the thermal trip to 70 degrees C. After Submersing it in the sink for a couple of hours the water warmed up, and the light did not dim, so something must be working ok.
Can anyone advise whether running with an internal temp of 70 degrees C will damage the NiMh cell?


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## Icarus (May 29, 2008)

Nice mod! :twothumbs

I have also some UK dive lights waiting to get modded. :duh2:
How thick is the heatsink? :thinking:


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## LukeA (May 29, 2008)

spearsniper said:


> Thanks for the heads up regarding heat build up in the casing. I have set the thermal trip to 70 degrees C. After Submersing it in the sink for a couple of hours the water warmed up, and the light did not dim, so something must be working ok.
> Can anyone advise whether running with an internal temp of 70 degrees C will damage the NiMh cell?



The capacity of the water to dissipate the heat from the LEDs so totally outweighs the thermal resistance of the plastic that the battery will never get hot. Dissipating ~30W over that fairly large surface area with water, even with the insulating properties of the plastic case, is nothing.


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## Doh!Nut (May 30, 2008)

Hi Spearsniper

I am looking to do something similar, infact ebay delivered my new metal housing this week:thumbsup:

Are those reflectors from LED-tech ? - Cree branded?
How did you find they fitted? Good quality?
The only problem with my new housing is that I have to open it to expose the battery charge plug :thumbsdow. This means I will be repeatedly exposing the reflectors to little knocks. Do you think it is possible to epoxy the reflectors in place?

Cheers
Nick


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## Surface Tension (Jun 19, 2008)

Great idea and nice work!

I used to have a UK like that. It's on the bottom of the ocean now though.


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## jawisa (May 17, 2013)

I saw this thread about converting an old UK1200 dive light. The conversion looks great but I am looking for a detailed listing of the LEDs and driver that was chosen as the originator did not list. Has any else tried this as I have contacted him with no response. Any help would be greatly appreciated.

James


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