Opinions please: New LED housing with maxflex heatsinking (photo heavy)

[iggs]

Trout and myself have been collaborating on a housing to take the imminent quad Cree kit from cutter. I've been talking shite and procrastinating over various drawings and firing relentless emails to Trout then he just goes and machines MK1 up one evening that is an amalgamation of our ideas just like that.

Key things we were thinking about are

1- transferring all that heat that the 4 Cree's will generate away from the back of the LED's and dissipating away into the air

2- heat sinking the maxflex board that will be needed to run the Crees. With 4 LED's running at 1000mA there is going to be up to 2.22 Watts to remove from the board

3- because the maxflex is going to need to me attached to the housing for heat sinking we wanted to ensure the light was not too like key hole brain surgery to build up. With power supply, onboard switch, remote switch, warning led and power leads to the Crees all needing plumbing in we wanted to be able to do it with as much access as possible

Here's what Chris (trout) knocked up

total time in the garage 6 hours but I did have a few problems with the drive belt slipping so should be able to improve on that time for future housings
raw materials cost 1.5 meters of 50 mm ali bar £ 60 . ali used for this housing 100 mm so that is about £4.00
8 m2 bolts @ .10 each = £0.80

I have trimmed it down somewhat and overall dimentions are

length 55 mm
diameter 43 mm

the front is 14.75 mm deep and 34 mm internal dia widening to 35 mm for the lens
the lens and mcpcb are bedded on thermal putty and held in place by the ring which is
33.5mm internal dia fixed with 4 m2 allen bolts , the final assembly would need some silicon under the ring for waterproofing.

The rear is 34 mm internal dia and 22.5 mm deep with a 6 mm hole for the wires from the leds

You can see on the picture above the groove that goes down behind the led mounting plate to improve cooling there

the tailcap is also fixed with 4 m2 bolts with the integral heat sink for the maxflex

the heat sink is 17.5 mm long , 12 mm wide and 9 mm high this will need tayloring in size to fit the maxflex on it will need shortening a tad , it is machined to be a close fit to the outer housing and a liberal coat of thermal putty should give good heat transfer. there is also the option of drilling and tapping into this block for a mounting bolt through the outer . this will also pull the heatsink tighter to the housing.

The idea is that the tail cap will carry Chris's 'mouse' momentary switch + a warning LED + cables for power input and remote momentary switch. All this will be able to be built up outside the housing and then slid in

It will actually be mounted 'upside down' with the heatsink at the top of the housing so that the heat is transfered to what should be one of the coolest areas being most exposed to the moving air and furthest away from the heat generated by the LED's

the total housing weighs approx 80 to 125 grammes on my kitchen scales. The rear could lose 3 rings if weight was a big issue but the front I think needs the extra mass

for the leds

So while this is a MK1 what does the CPF massive think?

Any comments and thoughts gratefully recieved

Ian

ps. trout is now registered on CPF (long story) so will be along in person shortly

 

[trout]

Ian thanks for putting that up looks good

I see the Maxflex 2 is bigger ,
from the maxflex thread
george
Be smart to wait - maxFlex2 will be 0.9" in diameter...

I haven't seen one yet - they are all at the assembly house on the other side of the country. When I receive them there'll be pictures etc.

good job I left material so it can be modded.

Trout

 

[dom]

Hey Guys -top job:thumbsup:

And :welcome: Trout

Great design with the sink to rear cover -will it get in the way of any of your wiring?
Looks like you have all your bases covered there -should be a cool as a cucumber

Cheers
Dom

 

[iggs]

Thanks Dom

I don't think it will 'get in the way' but the build up process is going to have to be done carefully. Because its all so close and not going to move once its done we should be able to fit it all together without actually soldering the maxflex joins until the last thing as the wiring will hold itself all together because its a fixed stucture if that makes sense

 

[trout]

Thanks for the welcome Dom. :thumbsup:
and hello everyone.

I dont think the maxflex heat sink will get in the way , more make it easier to do the wiring and then slide it in .

This is my switch design using the switch that comes with the blex
will this switch work with the Maxflex 2

the rubber cover sits in a 10mm hole with the edges undercut to hold it in place , it is old innertube .
it works a treat. and stands up to the UK wet weather

and all machined on my brothers 65 year old lathe.

 

[Geir68]

Hi
This is my design of a Cutter MR11 kit housing. Diameter is 39mm and length is about 45. I choose a threaded front ring to allow for quick lens changes. The MCPCB is pressed by the lens against a 7mm wall inside the housing with arctic-silver paste. This makes upgrading relatively easy, just soldering of two wires ;-)The helmet mounted bike light is running a Bflex controller of 4 18650's.

I can tell you straight away that you are not going to run 4 Cree diodes at 1000mAh in a light of these dimensions without airflow!! Mine 3 LEDs overheats (Bflex controlled) in about 5 min when I'm inside my house.

 

[trout]

Cool looking light you made there .

That will be the beauty of using the Maxflex2 for its controlability low power for climbing and standing around and eyeball melting high for warp factor downhills .

keep the opinions coming please.we need all the help we can get

Trout

 

[Geir68]

will this switch work with the Maxflex 2

All of the Taskled controllers are using "momentary On" switches. When you press the switch, the two wires to the switch gets contact with each other.
So Yes! you will be able to use this switch with Maxflex2!

I really like your design for the controller which is connected to the back cover. To make it even better, you could try and isolate the cover thermally by adding a gasket between it and the housing. This would reduce the heat flux from the housing to the cover.

:goodjob:

 

[trout]

Yes that is an idea though we worked to get a good fit
for a good heat transfer path to the housing .
but after testing this one if a gasket is needed then it is do,able .

The mflex mounting was Iggs idea mainly to do the wiring outside the housing and slide it in .

 

[Martin]

..I can tell you straight away that you are not going to run 4 Cree diodes at 1000mAh in a light of these dimensions without airflow!! Mine 3 LEDs overheats (Bflex controlled) in about 5 min when I'm inside my house.

If the light were powered from a dynamo, it could do with a lot less heat sinking as there would be quite a bit of draft whenever the power is high. A quad LED arrangement would be pretty much perfect for a dynamo, I like that.

 

[bfromcolo]

That's a great looking light! I am curious about how you manufactured the head. I have a 14" Delta lathe in the garage that my kid uses for wood working, but have never tried to lathe aluminum or any other metal for that matter. Do you use the same tools for this as wood working or do you have special turning tools? What do you start with for the stock, can you buy aluminum blocks to turn into the shape you are looking for?

Thanks

 

[HEY HEY ITS HENDO]

Hey now that is gonna be one seriously nice lookin light :thumbsup:
.......... and the bar mount?
QR bar bracket
.

 

[Mash]

Great looking housing! Also goes for Geir68s one!
I can immediately think of two variations on the theme:
1- Open back, with a small fan, and outlet slots near the head for indoor fixed lighting
2- Sealed unit as above, but with more fin area either as an additional piece, or machined into the casing, for outdoor fixed lighting.
If you were intending to sell these, I believe these would be good sellers!