Luxeon Flood heatsink idea

I have been tossing around an idea lately about a different approach to heatsinking for multiple Luxeons in a Mag that would:

a) Be reversible
b) Required no permanent modification to the Mag (I guess this relates to a)
c) Still have good thermal pathways

Have you ever noticed that if you take the head off of you Mag and remove the bezel ring, lens, and reflector, that the head can then be screwed back onto the Mag body backwards? That's what gave me this idea.
Here it is:

(click pic for fullsize)

The bulb and the bulb retaining nut are removed from the light. Next, this heatsink actually screws right into the inside of the Mag head. Then, the Mag head can be screwed onto the body until it stops (the body bottoms out on the underside of the base of the heatsink), and the protrusion slides into place where the bulb would normally go, making electrical contact. The + contact at the end would obviously have to be isolated, and a screw in the top of the heatsink could serve as the - contact for the Luxeons. There should be plenty of thermal pathways, as the threads make contact with the Mag head, the bottom lip of the heatsink sits on the flat area on the inside diameter of the Mag head, and the Mag body makes contact at the bottom of the heatsink. Not to mention the mass of the heatsink itself.

Ideally, this would be best used for floodlight applications, however small optics like the NX series or Fraen LP could also be used and be held in place by the Mag's lens if the top part of the heatsink was sized properly (thickness wise).

Well, whudda think? /ubbthreads/images/graemlins/grin.gif


I was going to make (or have made) one of these for myself and make a nice floodlight with it before presenting the idea, but I don't know when that is going to happen given the current (and predicted) state of my bank account. You could put just about as many Luxeons on there as you'd like to fit, and based on that they could be hooked up accordingly and the unit could be put into the correct sized light. (several 1w on a 4 cell, or several 5w on a six cell perhaps). Anyway, hope someone here on the forum can take this idea to some kind of fruition. /ubbthreads/images/graemlins/grinser2.gif

Hopefully, a manufacturer doesn't steal it, /ubbthreads/images/graemlins/mad.gif but I guess that's the risk I take by posting it. /ubbthreads/images/graemlins/icon3.gif

Later! -LmM.

Hmmm... /ubbthreads/images/graemlins/thinking.gif

Imagestation must be having issues, the pic was there, now all I get is a red X. /ubbthreads/images/graemlins/jpshakehead.gif

If you click the picture, you should still get the fullsize version though.

/ubbthreads/images/graemlins/blush.gif

I can see the pic though. Nice one /ubbthreads/images/graemlins/grin.gif
then leddie, the whole light will be FLOOD, with the photons getting out in every direction, right?
actually i am designing something similar, though not in a mag head and wish to have the light to go in approximately one direction (meant to be used as desktop lamp)

any idea? /ubbthreads/images/graemlins/tongue.gif

very nice! /ubbthreads/images/graemlins/grin.gif

one suggestion though. the cylindar on bottom isn't going to produce a very good ground path...
for one, the mag bulb is a deal thinner than the id of the pedistal, and even if you make it a tight fit it can be finicky.

what i did when i made dropin modules (dropin to the body, not the head.), is make a small shoulder, that contacts the top of the bulb post. this will provide a more reliable ground path.

Ditto re Roth. The head has a much smaller area to dissipate heat compared with the body. I'd probably heatsink to the body.

Which software did you use to make the drawings?

shiftd,
Yes, unless you used some kind of optic as I described, this would make a flood light.

Roth,
Actually, the small cylinder will go completely inside of the bulb post, and then the top of the bulb post will ground out on the underside of the threaded part of the heatsink when it is screwed down (however this is only part of the ground path). The threaded part of the heatsink will sit right on top of the Mag body, making contact with it, both thermally and electrically if the Anodize on the top of the Mag body is removed.

Hotbeam,
Because of the way this is designed to work, when the heatsink is screwed into the Mag head, and then the Mag head is screwed back onto the body, all main Al parts will be making contact (head to body, heatsink to head, and also heatsink to body) and will be tightly locked together. The tighter you screw it on, the better the contact. Acrtic silver could be used in the threads and on mating surfaces for even better contact, however I doubt it would really be needed.

icarus/everyone,
Actually just about everyone probably has the "software" to draw something like this. I just used the drawing feature in MS Word and then did a screenshot and made a .jpg out of it. Pretty easy actually. Right now, the drawing is not to scale, but in word you can draw lines 1/8" accurate (they snap to an invisible grid), and then scale it to the right size if desired.

I am going to go draw a cross-section of the HS in the mag body to make it more clear how this all fits together when complete. Be back shortly...

Here it is:

(click pic for fullsize)

Hope this clears it up.

Any other comments?

Looks like a neat idea.

But what are you going to do about the reflector?
Your led is going to sit alot higher in the head now.

jt,
No reflector used, this is mainly for a flood light. If you wanted to add some throw to it, small optics could be added and sandwiched by the lens (kinda like Inretech does). Also, with a proper spacer/holder, the PM6 reflectors could also be used.

Nice idea and nice drawings too!

ahhhhhh I see, hehe.
Then all is good. /ubbthreads/images/graemlins/smile.gif Nice work.

I have something similar to that idea , it screws into the
C mag head, it was originally posted here http://www.candlepowerforums.com/ubbthreads/showflat.php?Cat=&Board=UBB14&Number=380643&Forum=380643
these didn't have the positive contact, they just screwed in to the head and stopped at the body tube...
I suppose the positive contact could just be added, do you
want me to send you one ?, you can give it a shot.

red robby,
Yes, I remember that post now. I forgot that those screwed into the head. The problem I see with them is the finned top, that wouldn't be ideal for mounting an LS to, it'd need to be a flat surface.

All you would really need to do for the positive contact would be to drill a hole through them and add some kind of plug (maybe a dowel?) with the contact at the tip.

Anyway, that is the basic idea I had, just with a flat top.

the fins can be removed with a pair of needle nose pliers, here is a shot of one with some of the fins removed, and then buffed

Really... /ubbthreads/images/graemlins/thinking.gif

How thick is the remaining base? My heatsink idea came from a mod idea I had. I was thinking of making a flood light that would use at least 12 (maybe up to 16) 1W Luxeons driven in series/parallel off of a 6 D cell mag... I suppose I could fewer initially and see if the sinking is enough.

If that surface is thick enough and can be polished pretty flat, this would work pretty well. I may be interested in one of those sinks. I'll send you a PM.