Improving heat sinking on P60 style drop ins.

[superjett]

My account (and posts) was a casualty of the forum problems earlier this year, so I'll try to add some of my stuff back to this thread.

I have 3 MC-E Dealextreme torches with P60 dropins. I wrapped them in heavy foil from a baking pan and did some thermal imaging during/after to see if it really made a difference.

Yes is my answer.

This is with all 3 wrapped.

I'll try to post more later.

 

[Norm]

Superjett great to have you back, your images really gave this thread some substance :thumbsup:
Norm

 

[superjett]

Thanks Norm. I hate to see any forum have problems since I run a pretty large one myself and have been hacked before and know how much it sucks for everyone.

Here's a shot with just the one on the right wrapped. To me it appears it's transmitting the heat to the outer housing much more efficiently and evenly than the non-wrapped ones.

This is 20-25 minutes in with all 3 wrapped and they are heating pretty evenly.

This is when I decided to shut them off after over 35 minutes of them sitting on the floor of my office with no airflow to speak of. The left one ended up much hotter even though they pull the same current within .1amps of each other and to my eye are very close on light output.

I use them for mountain biking so there is almost always airflow and I haven't had a problem since wrapping them 11 months ago, though I haven't done much night riding this year.

 

[flashlight chronic]

I've tried the soda can strip method but found that the aluminum tape works better. My Surefire and Solarforce hosts warm up quicker w/ the tape. It also seems to conform better to the module and I tend to make mine pretty snug (less air gap).

 

[superjett]

Tighter is better that's for sure. Mine are at the point where I have to twist/push/twist/etc to get them in pretty hard. I never did add any thermal paste though, just a very thin film would probably help even more but since I haven't had any problems, it's probably not needed for mine.

 

[hank]

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[RI Chevy]

Excellent posts. Thank you for Re-updating this with the missing posts! And images.

 

[jonnyfgroove]

The copper tape offered over on the marketplace is very effective on my P60 drop ins. Better than aluminum strips or aluminum tape, in my experience.

Thanks superjett for the FLIR images, awesome stuff.

 

[brianbucar]

if you are using aluminum can bits in your lights, there is a plastic liner on the inside of the can.

i took my can, cut off either end and a slice down the middle lengthwise to make a sheet of aluminum. then i get out the acetone and a paper towel/rag and start wiping the plastic liner away on the inside of the can. youll know when you got it all off cause the can will look different and youll get black stuff on your rag/towel.

i wiped the outside of the can off too but it doesnt seem to touch the ink so its probably fine to leave. i may take one and stainless steel brush the outside of the can but i dont think it will matter much.

a little thermal heatsink goop lightly smeared into the aluminum should help but dont go crazy. very thin layer.

i dont have the goop installed in mine but i have around 4 layers of the aluminum can in my wf-501a with a xpg r5 drop in at 1.3-1.4a and it heats up the outside of the light in seconds.

i also cleaned up the burrs on the edge of the aluminum from cutting it but i used a utility knife.

i also laid the can material on some wood and laid a metal ruler on top of the metal and used the utility knife to cut it. makes a perfect straight cut.

im going to do this to all my p60 lights as some of them still have aluminum foil for the heat transfer stuff.

brian

 

[Norm]

:welcome: Brian

You'll notice in the first post I cleaned both sides of the aluminum with steel wool, leaving just bare aluminum as seen in the photos.

Norm

 

[texas cop]

I tried the soda can solution then the wrapped aluminum foil. Can method nice but takes a bit of final trimming. Foil can get that tight perfect fit but slides a bit as I seat the pill. Yesterday I tried the adhesive aluminum tape. Got to say I much perfer the tape method it stays exactly where I put it.

 

[brianbucar]

:welcome: Brian

You'll notice in the first post I cleaned both sides of the aluminum with steel wool, leaving just bare aluminum as seen in the photos.

Norm

thanks. ive been lurking for about a month or so. made an intro post the other day and got sucked in already lol.

yeah i saw your pics. years ago in college i experimented with that aluminum brazing rod stuff and they recommended using stainless steel brushes to get the aluminum oxide off of the metal and acetone to get off other impurities. im just applying that stuff here to flashlights. .

I tried the soda can solution then the wrapped aluminum foil. Can method nice but takes a bit of final trimming. Foil can get that tight perfect fit but slides a bit as I seat the pill. Yesterday I tried the adhesive aluminum tape. Got to say I much perfer the tape method it stays exactly where I put it.

i like the aluminum can method because there are less layers. every layer adds a little bit of inefficiency.

i took my digital caliper and measured around a .0365" difference between the inside diameter of my flashlights and the p60 drop in. i got a piece of .040 aluminum and sanded it to ~.036" and then wrapped the drop-in and tried to insert it. wouldnt fit. i assume it was because there were bumps and such in the aluminum from bending it around the module, sanding and working with the piece and to get a good fit, id have to press the parts together with a bit of heatsink paste on the spacer, the module and the light itself.

since i like to swap parts between all my lights, i wasnt willing to press fit my stuff together for the ultimate in heat conduction.

i find that the aluminum can method is the next best thing. i have to give it a pretty good twist/push to get the module into the light.

i do have to trim the aluminum so that the beginning of the can metal and the end of the can metal dont overlap so that that the in-between-layers have room to flex as each layer transitions to the next layer so that the maximum amount of aluminum sheeting is contacting the next layer.

either way, anything is better than not adding metal to try to pull the heat from the module to the body.

Brian

 

[Hondo]

i took my digital caliper and measured around a .0365" difference between the inside diameter of my flashlights and the p60 drop in. i got a piece of .040 aluminum and sanded it to ~.036" and then wrapped the drop-in and tried to insert it. wouldnt fit.

Actually, that was because you did not account for the aluminum on both sides of the module. You measured the difference in diameter, so your sheet needs to be half that in thickness, or about 0.018".

Seems to me the aluminum food serving trays might be the best compromise, as they would not have a coating to remove, but require much less layers than aluminum foil.

 

[Kestrel]

FWIW, I have done some limited trial-and-error with my dropins and the various metallic tapes available here on CPF.

With regards to fitment in SureFire hosts, my experiences are as follows:

• Moddoo dropins - too small a gap for any tape I've tried
• Malkoff dropins - too small a gap for the commonly-available copper tape, just right for a single layer of the thinner aluminum tape from Vinhguyen54
• Vinhguyen54 dropins - two layers of the aluminum tape that he supplies makes for a perfect fit

I have not yet pursued this with shim stock etc, as the adhesive metallic tapes seem to work well enough for me. :shrug:

 

[TadpolePilot]

The beer can thing!
I did everything just so perfect.
I installed 2 - 4 1/4" X 5/8" stripes into two led flashlights.
Number one is a SolarForce L-2-P Special Edition HA-III.
This was a pressure fit I lubed used my work gloves to push it in and tighten.
Number two is a Insight Tech Gear model H X- 150-r rechargeable 1 x 18650 cell.
They both had four layers of heavy-duty kitchen alumumin
foil I installed four weeks ago.
Results in number one I could feel the bezel get warm with the tin-foil and no feeling of unit getting warm?
Number two same as number one.
I now will go to bed and cry! LOL He he ha ha
What to do?

 

[yifu]

Al foil and copper tape is fine and all but what about actual heat sinking heads like the Cryos bezel or the FiveMega Beefy heat sink? They are much heavier than the standard Z44 bezel and have a lot more surface area for heat transfer.

 

[tam17]

Just did what Norm recommended in the beginning of this thread. The only difference is that I've used carefully flattened and cleaned copper strips. There was a really huge gap between my Solarforce L2 and its stock XR-E drop-in, so three layers were needed for a snug fit.

Improvement is obvious: the whole head heats up fairly quickly, instead of the top portion (where tapered surfaces make firm contact even without the wrap), and the whole flashlight soon starts to act like a massive heatsink... Thanks to OP and others!

Cheers,

Tam

 

[Redhans]

Experiment: Aluminum Can Heat Sink vs Copper Tape Heat Sink

Thank you Norm and everyone who has contributed here.

I have a surface temperature laser, brushed aluminum can strips, and a little bit of copper tape. I measured heat over time using both materials as a heat sink. In theory, the one with the higher surface temperature is the heat sink that is most effective at transferring heat away from the LED and to the surface of the flashlight.
The setup was controlled: room temp, battery voltage to nearest hundredth, position of laser, I measured temperature at a distance of 4 inches, and aimed the laser at the base of the flashlight head. I used a Solarforce L2M, a Nichia 219 dropin on maximum output, and new power cells with voltages verified by multimeter. Time was accurately kept by use of an interval timer set to go off every minute.

I seem to be unable to upload pictures. I only see an option to link to a picture URL and I'm not going to bother with that at this time. I will just insert a table of my results instead.

Time	Temp (F) Al sink	Temp (F) Cu sink
0	82	81
1	86.5	84.5
2	90	88.5
3	93	91.5
4	96	94
5	98	96.5
6	99.5	98.5
7	101.5	100.5
8	103	102
9	104.5	103
10	105.5	104.5
11	106.5	106
12	108	107.5
13	109	108
14	110	108.5
15	110.5	109.5
16	111	110.5
17	112	111.5
18	113	112
19	113.5	112.5
20	114	112.5
21	114.5	113.5
22	114.5	114
23	115	114.5
24	115.5	114.5
25	115.5	115
26	116	115.5
27	116.5	116
28	116.5	116
29	117	116.5
30	117	116.5
31	117	116.6
32	117.5	117
33	117.5	117
34	117.5	117
35	117.5	117
36	117.5	117.5
37	117.5	117.5
38	117.5	117.5
39	118	117.5
40	118	117.5
41	118	117.5
42	118	117.5
43	118	117.5
44	118	117.5
45	118	117.5

These temperatures are remarkably similar. The rates of temperature change remained in lock-step, with surface temperature from copper tape being about 0.5 degrees cooler for the duration of the test.

Conclusion: There is no significant difference between the aluminum can strips and the copper tape as measured by heat transferred to the surface of the flashlight. I would choose the brushed aluminum can heat sink option because it is virtually free of cost, readily available, easier fit into the air space than copper tape, and slightly better during short light bursts.

Errors: I could have done a better job covering the dead air space with both the Al and Cu sinks. The aluminum strips were slightly wider than the copper tape by about 3mm. A control test run could be performed.

-Redhans

 

[Kestrel]

Re: Experiment: Aluminum Can Heat Sink vs Copper Tape Heat Sink

Hello Redhans, :welcome:
Looking forward to seeing your test data.

 

[texas cop]

Re: Experiment: Aluminum Can Heat Sink vs Copper Tape Heat Sink

I've changed to the soda can method and the best soda can for me is the 24 ounce Monsters. The metal is much thicker than normal soda cans at 0.004". One 8" strip usually gives a very snug fit. 8" is also conviently the circumference of the big can.