Malkoff        
Page 1 of 4 1234 LastLast
Results 1 to 30 of 96

Thread: Thermal Properties of Titanium - by Prof. McGizmo

  1. #1
    Moderator
    Kiessling's Avatar
    Join Date
    Nov 2002
    Location
    Germany, Old World
    Posts
    16,137

    Default Thermal Properties of Titanium - by Prof. McGizmo

    This is the split-off part of the McLuxIII-T sales thread containing the discussion about the thermal properties of titanium.
    bernhard



    Anyone notice that the McLuxIII-T is getting warm much quicker than the PD? Mine does this ... and I double checked against my two PDs ... the T heats up quicker while the brightness is comparable ... what's that? The mass of the piston? Does not sound plausible.
    The steady state is about the same temperature ... meaning warm and very warm if left on aunattended for a very long time, but not uncomfortable at all.
    bk
    Last edited by Kiessling; 12-29-2005 at 05:51 PM.
    There is a type of perfection that transcends the quest for lumens. Buying a $250 1-cell light for "lum factor" is like buying a $250 single malt Scotch for the alcohol content.
    - paulr


    It's always darkest just before it goes pitch black.
    My shoes are too tight. But it doesn't matter, because I have forgotten how to dance.

  2. #2

    Default Re: McLuxIII-T (titanium) **SOLD**

    >>Anyone notice that the McLuxIII-T is getting warm much quicker than the PD? Mine does this ...

    Correct.

    Ti has horrible heat management. All Titanium, any grade. This is the number one drawback of Ti (two being cost..) for use in flashlights.

    (The Ti LC I had, while being a work of art and design, was overdriven and melted my hands off when I used it on high. And I always use the brightest setting on my lights, brighter is better, hence I had to let go of it..)

    You really have to make a choice when considering Ti:

    Do I want something that won't rust, is super strong and very pretty (OOh, Ahhh) or do I want something that's going to handle heat much, much better..

    For myself, I love Ti. When set at the correct levels, such as on the Ti PD, it can be usefull AND pretty, but until a quantum leap in heat management comes around Ti is going to remain in the back of the pack for flashlights.

    That's IMHO...

  3. #3
    Moderator
    Kiessling's Avatar
    Join Date
    Nov 2002
    Location
    Germany, Old World
    Posts
    16,137

    Default Re: McLuxIII-T (titanium) **SOLD**

    I don't think so. A warm ight is an indicator of a very good heat transfer from the LED away to the metal of the body as intended.
    That's why I am startled at the behaviour of the McLuxIII-T ... it should get warm *after* the regular PD ...
    bernie
    There is a type of perfection that transcends the quest for lumens. Buying a $250 1-cell light for "lum factor" is like buying a $250 single malt Scotch for the alcohol content.
    - paulr


    It's always darkest just before it goes pitch black.
    My shoes are too tight. But it doesn't matter, because I have forgotten how to dance.

  4. #4
    Flashaholic* Anglepoise's Avatar
    Join Date
    Nov 2004
    Location
    Pacific Northwest
    Posts
    1,554

    Default Re: McLuxIII-T (titanium) **SOLD**

    Thats right.
    The TI should take much longer to 'heat up'.
    David............................................." Some Homemade Creations"

  5. #5

    Default Re: McLuxIII-T (titanium) **SOLD**

    >>A warm ight is an indicator of a very good heat transfer from the LED away to the metal of the body as intended. That's why I am startled at the behaviour of the McLuxIII-T ... it should get warm *after* the regular PD ...

    Not as far as I understand it. Unless I'm completely off my rocker, and that is a good possibility, the heat is transfered from the LED, as intended by the excellent design of Don's, to the Titanium, that has heat conductivity issues and heats much faster than the Aluninum / Steel / Copper / Whatever you want to use..

  6. #6
    Moderator
    Kiessling's Avatar
    Join Date
    Nov 2002
    Location
    Germany, Old World
    Posts
    16,137

    Default Re: McLuxIII-T (titanium) **SOLD**

    Uh oh ... I guess we'll have to wait for the experts then ... ... because I am not absolutely sure either, even if I'd like to play teacher here
    bernie
    There is a type of perfection that transcends the quest for lumens. Buying a $250 1-cell light for "lum factor" is like buying a $250 single malt Scotch for the alcohol content.
    - paulr


    It's always darkest just before it goes pitch black.
    My shoes are too tight. But it doesn't matter, because I have forgotten how to dance.

  7. #7

    Default Re: McLuxIII-T (titanium) **SOLD**

    >>Uh oh ... I guess we'll have to wait for the experts then ... ... because I am not absolutely sure either, even if I'd like to play teacher here

    Yeah. I'm pretty sure I'm right about this but we'll wait for the "Big Guns" to clarify it..

    No harm done, hopefully we'll get a lesson out of this and learn something to boot.

  8. #8
    Flashaholic* MorpheusT1's Avatar
    Join Date
    Mar 2005
    Location
    Norway
    Posts
    2,831

    Default Re: McLuxIII-T (titanium) **SOLD**

    I would have to say i disagree on this one.

    My experience is that if the HeatSink/Flashlight body is getting warm there is some good conductivity going on.

    I have some experience with overclocking CPU`s and using diffrent Heatsinks.And there is always a good sign when the HS is getting warm,this means that the heat is taken away from the source.

    But i do know one thing and that is that Ti is not the best conductor,but would think it is very safe when running at low levels like Don is doing.
    And if the Ti is getting warm some conductivity is getting away from the led which is good


    Experts please correct me if im wrong,this is only my own experience talking and nothing more.

    But i do think Bernie is right about this.



    Benny
    Quote Originally Posted by bmstrong
    >>Uh oh ... I guess we'll have to wait for the experts then ... ... because I am not absolutely sure either, even if I'd like to play teacher here

    Yeah. I'm pretty sure I'm right about this but we'll wait for the "Big Guns" to clarify it..

    No harm done, hopefully we'll get a lesson out of this and learn something to boot.

  9. #9
    *Flashaholic* McGizmo's Avatar
    Join Date
    May 2002
    Location
    Maui
    Posts
    17,264

    Default Re: McLuxIII-T (titanium) **SOLD**

    Hi guys,
    I admit to being in a position where I wish I knew more about the thermodynamics of these lights but I have also gotten to the point that I realize that just numbers of thermal resistance or thermal conductivity don't give you the full picture of a complete system and the ultimate steady state unless you know how to work with those numbers!!! The time it takes for heat to migrate to the surface of the flashlight is a function of mass, volume and thermal boundaries as well as the resistance to such thermal migration. However once the heat is distributed within the system and at diferentials determined by the thermal boundaries and deltas in conductivity, the heat needs to leave or it will continue to build up and steady state would be higher. Although Ti is not nearly as conductive as most Al, it is more conductive than air and I suspect our hands. It is more conductive than water! There is a greater thermal differential between the Ti surface and the LED slug than if the light were Al but the ultimate health and steady state temp depends on the ambient surrounds and contact of the light with external thermal "relievers". The "real" bottle neck to thermal relief of the light is most likely at the surface of the light.

    On the T, I think you can notice that the head and specifically the area just outside of the heat sink will get warm noticibly and more so than the head at the bezel and the power pack. There is a lag time for the balance of the light to reach higher temperatures. On an Al light, the head will be more uniform in temp and the battery tube in Al will warm up quicker. The thermal resistance of Ti is greater than Al and you can feel the difference. However, the heat does propigate out and there is thermal conduction. The die temp of the LED will be greater in a Ti host. However, how much greater and does it spell trouble? I don't think so with the drive levels used in the T and in most operating conditions. If you set the light on the dash of your car in the desert with a dry ambient environment and temp of 140F, I think there will be some issues with the lumen maintenance of the LED and I doubt the converter electronics will be happy! OTOH, an Al light would also be in a taxed and less then optimal environment.

    In the thermal test I did which consisted of just the head and no relief available from the additional mass and surface area of a battery tube, there was a delta in temp between the core of the heat sink just below the slug and the surface of the head of 30 degrees F. This is not a show stopper as far as I can determine! BTW, I see I still have the legend in my thermal test screwed up and show the sink and surface temps reversed.

    Ultimately, you are relying on the air or your hand to remove the heat from the light and neither are even close to being as effective as the Ti is. The answer is to not generate too much heat in the first place or have a bunch of mass and surface area to deal with the heat!! I don't abide by the philosophy of the LED being a disposable component of the flashlight even if its replacement is reasonably simple.

    It is my perception that A) if heat is generated that B) the sooner one is aware of this at the surface the better the system is at passing this waste on! A lack of evidence at the surface is a sign of thermal constipation and undue pressure on the heat source itself! If you have a heavy consumer, you have a heavy "load" of heat to be passed! If there is no sign of this heat being passed then Uh Oh! In the interest of health and regularity, we shouldn't feed the LED's any more fuel than they are equiped, in situ, of processing and passing on! OK, so I am not qualified to discuss this thermal stuff either, I do feel qualified to speculate and observe in regards to potty training 101 of small flashlights! Match the input with the output capabilities!
    Build Prices .... some mods and builds (not 4 sale) "Nature can be cruel- but we don't have to be."~ Temple Grandin

  10. #10
    Flashaholic* MorpheusT1's Avatar
    Join Date
    Mar 2005
    Location
    Norway
    Posts
    2,831

    Default Re: McLuxIII-T (titanium) **SOLD**




    What he said!



    LOL

  11. #11
    Moderator
    arewethereyetdad's Avatar
    Join Date
    Nov 2003
    Location
    Kansas City, MO
    Posts
    8,360

    Default Re: McLuxIII-T (titanium) **SOLD**

    Quote Originally Posted by MorpheusT1



    What he said!



    LOL
    I had visions of the Scarecrow's speech once he got his brain. All that brilliant stuff he said, none of which anyone understood.

  12. #12
    Moderator
    Kiessling's Avatar
    Join Date
    Nov 2002
    Location
    Germany, Old World
    Posts
    16,137

    Default Re: McLuxIII-T (titanium) **SOLD**

    Ahem ... yeah ... ...
    And why is my T heating up faster than the PD then? Not that I didn't understand you post, Don, but ...
    bernie

    PS: did all of you T-owners experience this or am I the only weirdo?
    Last edited by Kiessling; 12-28-2005 at 05:04 PM.
    There is a type of perfection that transcends the quest for lumens. Buying a $250 1-cell light for "lum factor" is like buying a $250 single malt Scotch for the alcohol content.
    - paulr


    It's always darkest just before it goes pitch black.
    My shoes are too tight. But it doesn't matter, because I have forgotten how to dance.

  13. #13
    *Flashaholic* McGizmo's Avatar
    Join Date
    May 2002
    Location
    Maui
    Posts
    17,264

    Default Re: McLuxIII-T (titanium) **SOLD**

    Dang! I came to this post for a reason and got caught up in typing well beyond my ken and level of understanding!

    I have now built out all of the remaining sets which I had converters for. Those of you who are getting your T's now have been notified (actually last night and early this AM). If you did not get a postage notification then unfortunately you will be waiting with me for the next set of converters to arrive. In the meant time, if you have buyers remorse then feel free to let me know and take you off the list. Any of you who receive your lights and do not feel they meet with your expectations can also send them back for a full refund. As has been the case with most of my stuff, there is no warranty beyond my choice of doing what I felt was right and dependant on the circumstances. I don't want any of you to buy or keep one of these lights if you are not satisfied with the acquisition! Those planning on keeping their T's as shelf queens or collectables can use the fancy presentation case the light was shipped in! (Yes, that would be the recycled bubble wrap envelope with used masking tape on it!)
    Build Prices .... some mods and builds (not 4 sale) "Nature can be cruel- but we don't have to be."~ Temple Grandin

  14. #14
    *Flashaholic* McGizmo's Avatar
    Join Date
    May 2002
    Location
    Maui
    Posts
    17,264

    Default Re: McLuxIII-T (titanium) **SOLD**

    Bernie,
    Your comment makes me concerned that your light might have a short or something going on?!?! That or you are feeling the heat localized in the area adjacent to the sink because the heat does not spread throughout the light nearly as fast as it will on a PD?!?!

    Turn on a PD and the T and hold them by the bezel and see which one warms up first.
    Build Prices .... some mods and builds (not 4 sale) "Nature can be cruel- but we don't have to be."~ Temple Grandin

  15. #15
    Moderator
    Kiessling's Avatar
    Join Date
    Nov 2002
    Location
    Germany, Old World
    Posts
    16,137

    Default Re: McLuxIII-T (titanium) **SOLD**

    Hm ... the T warms up considerably faster than my two PDs (I did the test twice) ... you get the feeling "warm" when the PDs are still "cold ... or wait ... maybe a little warmer than cold?".
    The max heat develops in the upper end of the body where the threads are, right in the area where the head screws in. The visible part of the head above the threads (reflector et al) doesn't really get warmer than a PD.
    In the inside ... the contacts are clean, no part that I can touch gets excessively hot, the battery isn't hot and there is no sound of "arcing" to be heard.
    BUT ... on the long run I can see an ever so slight but repeating flicker when running on high that cannot be caused ba a depleted battery (tested twice).
    In continious burn it won't get hot either, it just stays warm during the time the PDs build up their heat maximum.

    Now Dr. McGizmo ... whats the diagnosis?

    Your Highness ... what's the verdict?



    bernie
    There is a type of perfection that transcends the quest for lumens. Buying a $250 1-cell light for "lum factor" is like buying a $250 single malt Scotch for the alcohol content.
    - paulr


    It's always darkest just before it goes pitch black.
    My shoes are too tight. But it doesn't matter, because I have forgotten how to dance.

  16. #16
    Moderator
    Kiessling's Avatar
    Join Date
    Nov 2002
    Location
    Germany, Old World
    Posts
    16,137

    Default Re: McLuxIII-T (titanium) **SOLD**

    Brightness seems about right ... a little less bright than the U-bin PD and a more diffused "Joker"-spot.
    There is a type of perfection that transcends the quest for lumens. Buying a $250 1-cell light for "lum factor" is like buying a $250 single malt Scotch for the alcohol content.
    - paulr


    It's always darkest just before it goes pitch black.
    My shoes are too tight. But it doesn't matter, because I have forgotten how to dance.

  17. #17
    *Flashaholic* McGizmo's Avatar
    Join Date
    May 2002
    Location
    Maui
    Posts
    17,264

    Default Re: McLuxIII-T (titanium) **SOLD**

    Bernie,
    I am an electronics dummy so there is a black box in this equation. I am not sure what is going on with your light or if it is pecularliar or abnormal. I also don't feel very savant at the moment so I won't tax either of my remaning brain cells on deciding if I understand your observations and further if I can explain them. If the light works and seems to be working, cool. If you think it is acting up, then we will need to see if we can get some beter minds on this or you can send it back and I can swap out components if it seems to be erratic after I give it a whirl on the bench.
    Build Prices .... some mods and builds (not 4 sale) "Nature can be cruel- but we don't have to be."~ Temple Grandin

  18. #18
    Flashaholic*
    Join Date
    Dec 2004
    Location
    PNW
    Posts
    657

    Default Re: McLuxIII-T (titanium) **SOLD**

    From this table: Titanium - Comparison of Properties with Other Metals it seems that Ti has a LOWER "Thermal conductivity coefficient", thus, a POOR conductor of heat, with cooper being the BEST conductor. So, if everything else is the same, LED, heatsinking, etc., and the only difference is the body material of the light, then the Ti body light should NOT conduct heat(will be less warm) as much as Al.
    Last edited by seattlite; 12-28-2005 at 06:44 PM.

  19. #19
    Moderator
    Kiessling's Avatar
    Join Date
    Nov 2002
    Location
    Germany, Old World
    Posts
    16,137

    Default Re: McLuxIII-T (titanium) **SOLD**

    I repeated the test with the ti-head on the PD body ... and all was normal ... meaning they both got warm relatively simultaneously and only the ti-bezel stayed significantly cooler ... which could mean that the reduced heat transfer in the ti together with the significantly smaller (in volume) ti body could generate a more rapid heat build-up in the threaded section due to the good transfer from the al heatsink, but the heat then stays there longer making this area of the light warmer than the standard PD. As the heat then spreads the bigger volume of the aluminium body takes longer to heat up than the smaller ti body (no piston, mind you!), which would make the ti-light warmer again ... thus simulating a better heat transfer (by a warmer light) in the end where there is only less metal volume and less heat trasnfer in the ti compared to the al.

    Theory sounds goofy

    Oh and btw ... no way in hell I am sending this one back!
    In the worst case I can always wait for the K2 upgrade kit ...

    bernie

    P.S.: interesting to see how unsecure we feel when venturing into new territory ... titanium.
    There is a type of perfection that transcends the quest for lumens. Buying a $250 1-cell light for "lum factor" is like buying a $250 single malt Scotch for the alcohol content.
    - paulr


    It's always darkest just before it goes pitch black.
    My shoes are too tight. But it doesn't matter, because I have forgotten how to dance.

  20. #20
    Flashaholic* Beamhead's Avatar
    Join Date
    Jul 2004
    Location
    gone "Squatchin" :p
    Posts
    4,126

    Default Re: McLuxIII-T (titanium) **SOLD**

    Can I come out of left field with my warped thinking.....

    On the McLux III T(i), it utilizes an Al slug for the LED, is it possible that the slug is pulling heat at a greater rate than the Ti it makes contact with.......thus creating a heat transfer bottleneck at the Al slug Ti junction if you will.......

    I will shudup now as I didn't even buy one of these gems.
    Wrong time of the year for me...
    Quando Omni Flunkis Moritati

  21. #21
    *Flashaholic*
    tvodrd's Avatar
    Join Date
    Dec 2002
    Location
    Hawthorne, NV
    Posts
    4,987

    Default Re: McLuxIII-T (titanium) **SOLD**

    To add additional confusion to the materials' thermodynamic properties, Ti has about half the specific heat of Al. Put the same amount of work/heat into a 1# Ti block and a 1# Al block, starting at the same ambient, and the Ti one will exhibit ~twice the temperature increase from ambient.

    Larry
    So much for not being able to find my happy a** with both hands and a flashlight! (Do not look into Tank Searchlight with remaining eye!)

  22. #22
    *Flashaholic* McGizmo's Avatar
    Join Date
    May 2002
    Location
    Maui
    Posts
    17,264

    Default Re: McLuxIII-T (titanium) **SOLD**

    Beam,

    I agree that there is a thermal barrier at the junction of the Al slug and Ti seat and this is the area where the Ti will start to show more heat and remain hottest.

    Bernie,
    Your explainations sounds good to me.

    seattlite,
    Thanks for that table! I wish it had water and a air and a human hand in there too! Ti does conduct heat and heat is energy that has to go some where or be transfered into another form of energy. Ultimately the heat will leave the flashlight if the flashlight's environment is at a lower temperature. The heat will leave in conduction with any object contacting the light including a hand and air molecules contacting the light. The heat will also leave via radiation.

    Since the al slug is more conductive than the Ti, it will remain at a higher temperature than the Ti as long as heat continues to be generated by the LED and while the light is in a steady state. Consequently, I would expect the surface temp of the Ti light to be lower than that of a similar light in Al. There will be more of a temperature gradiant spreading out on the Ti lights surface than on a similar light in Al as well. The tail of the Ti light would be measurably cooler than that of an Al light. From the table cited, Al is about 11 X more conductive than the Ti. However the Ti is conductive and the important question is whether it is conductive enough to to allow the the LED's die to operate at an acceptable temperature. From what I can gather, the answer here is yes. It is important to remember that steady state temperature depends on the ambient conditions and the conductivity of the ambient contact with the light. Air sucks at conductivity!!!! The real bottle neck is outside of the flashlight (in most cases)!
    Build Prices .... some mods and builds (not 4 sale) "Nature can be cruel- but we don't have to be."~ Temple Grandin

  23. #23
    Flashaholic* Beamhead's Avatar
    Join Date
    Jul 2004
    Location
    gone "Squatchin" :p
    Posts
    4,126

    Default Re: McLuxIII-T (titanium) **SOLD**

    McGizmo, I hope you did not interpret my post as stating any flaws in the design and operation of this beautiful piece of engineering artwork. That was not my intent at all.

    I will say for the record that I did own an Al light that "cooked" the LED and it would get almost too hot to handle.
    I highly doubt that the McLux III T is getting anywhere near that.
    Quando Omni Flunkis Moritati

  24. #24
    Flashaholic*
    Join Date
    Dec 2004
    Location
    PNW
    Posts
    657

    Default Re: McLuxIII-T (titanium) **SOLD**

    Quote Originally Posted by McGizmo
    ...
    seattlite,
    Thanks for that table! I wish it had water and a air and a human hand in there too! Ti does conduct heat and heat is energy that has to go some where or be transfered into another form of energy. Ultimately the heat will leave the flashlight if the flashlight's environment is at a lower temperature. The heat will leave in conduction with any object contacting the light including a hand and air molecules contacting the light. The heat will also leave via radiation.
    ...
    Ask and you shall receive: Thermal Conductivity . But, no human hand

  25. #25
    *Flashaholic*
    Join Date
    Dec 2003
    Location
    USA
    Posts
    8,182

    Default Re: McLuxIII-T (titanium) **SOLD**

    just got back in from a bike ride using mclux ti as main light.
    normally I would be using my niterider HID, but I loan it out.

    used Mclux ti for one hour+ run with no heat issues. outside temp was aprox. 50 degree cooling mclux ti with cool air flowing by.

    real world use is what counts

  26. #26
    *Flashaholic* McGizmo's Avatar
    Join Date
    May 2002
    Location
    Maui
    Posts
    17,264

    Default Re: McLuxIII-T (titanium) **SOLD**

    Thanks!! So Al is .5 and Ti is .04 . Al is 12 x more conductive than Ti.

    Now, water is .0014 and air is .000057. Ti is 29 x more conductive than water and 700 x more conductive than air (at 0 C)! I doubt the human hand is any more conductive than water; probably less. Also the human hand is presumeably dealing with a core temp of 98 degrees F so it will not be pulling heat out of the light until it is above 98F.

    Now slightly OT, what does this all have to do with the sale of some flashlights about which this thread was based?

    Yet one more interesting discussion to be lost in the archives...... No surprise here though really! If you consider the moderators of this particular forum, well, I really shouldn't say...
    Build Prices .... some mods and builds (not 4 sale) "Nature can be cruel- but we don't have to be."~ Temple Grandin

  27. #27
    Flashaholic* yaesumofo's Avatar
    Join Date
    Jul 2003
    Location
    Eastern Pacific, LAX DM03 sw actual
    Posts
    3,696

    Default Re: McLuxIII-T (titanium) **SOLD**

    I would have to say that thermal performance it totally ON topic Don. Heck it is a performance aspect of a particluar flashlight (all flashlights).

    If we can't talk about thermal perfomance what the heck can we talk about?
    It is like going to da car dealership and not being able to discuss the gas mileage. Silly.
    Anyway. My only other flashlight which is titanium (1/2 titanium) is the Ti Ag raw.
    The Ag head gets hot much quicker than the Ti body. The Body does get hot though.
    To look at thermal performance of these lights one has to look at the TIME factor. I think.
    Being that the body is somewhere around 70% water it dosen't suprise me that it is not that great a heat conductor. This I know for sure a flashlight held in the hand will take longer to get too hot to hold than a light sitting on a table. With enough energy and time both will acheive that too hot state.
    Even though the body is not that great a conductor of heat it is still pretty good at it in the real world.
    I think you summed it up perfectly when you said somthing about balancing the capicity of the flashlights Body ability to move heat away from the emitter with the emitters ability to produce heat. That makes it clear to me anyway. Thanks.
    yaesumofo



    Quote Originally Posted by McGizmo
    Thanks!! So Al is .5 and Ti is .04 . Al is 12 x more conductive than Ti.

    Now, water is .0014 and air is .000057. Ti is 29 x more conductive than water and 700 x more conductive than air (at 0 C)! I doubt the human hand is any more conductive than water; probably less. Also the human hand is presumeably dealing with a core temp of 98 degrees F so it will not be pulling heat out of the light until it is above 98F.

    Now slightly OT, what does this all have to do with the sale of some flashlights about which this thread was based?

    Yet one more interesting discussion to be lost in the archives...... No surprise here though really! If you consider the moderators of this particular forum, well, I really shouldn't say...
    Support your local flashlight builder.
    Buy American. Stop crying and start Buying.
    Flashlights are tools. Period.

  28. #28
    Flashaholic* mattheww50's Avatar
    Join Date
    Jun 2003
    Location
    SW Pennsylvania
    Posts
    1,049

    Default Re: McLuxIII-T (titanium) **SOLD**

    98 degrees is a core temperature. Extremities (feet,hands,toes,arms,legs) are generally much cooler, and much closer to ambient air temperatures. Thermal conductivity however is close to water (because as soon as the skins starts to get warm, it releases water from seat glands. Also keep in mind that you are holding onto a flashlight, the thermal resistance per unit area may be relatively high, but the contact area is often quite large, so substantial amounts of heat can be transferred. aluminium is not a fabulous conductor of electricity, but if you make the conductor cross section big enough, the resistance per meter can be lower than smaller cross section copper.

    In the worst case, you can put a copper (silver is a little better than copper, both are much better than Al) slug between the aluminium and Titanium to increase the effective contact area between Al slug the Luxeon sits on, and the Ti heat sink. The trick is to put a very low thermal resistance material in direct contact with the Al Slug, and let that material provide the large contact area with the poorer thermal conductivity Ti. Cookware has done this for decades. Put an Aluminium or Copper bottom on a Stainless Steel pot.
    -- Al slug
    ------------ Cu slug
    ------------- Ti material

  29. #29
    *Flashaholic* McGizmo's Avatar
    Join Date
    May 2002
    Location
    Maui
    Posts
    17,264

    Default Re: McLuxIII-T (titanium) **SOLD**

    Thanks Bill! I don't think I have been able to capture these lights properly in a picture but I have never been satisfied with any of my shots of Ti items. The silver metals all have their own tones and it is tough to capture this for some reason. The Ti has a "smoke" in its color that is subtle I think.

    Mattheww50,

    I believe I have sufficient face to face contact between the Ti internal shoulder and the Al heat sink for a reasonable path and this face is in some compression due to the screw clamping the PCB and heat sink on either side of the Ti ring bulkhead. I am using the arctic ceramic grease that is supposed to be a real good thermal grease. Perhaps I should get back to my diamond bog! On another Ti light I started to build with a Nichia Jupiter, I surface mounted the Nichia with solder to a sterling silver heat sink. I never completed that light but did do another using a Luxeon on a sterling silver heat sink. If I were going to move a Ti light into turbo or nitrous mode, I think it would be cool to surface mount a K2 on a sterling silver heat sink. However, I still think that a 1xCR123 light in the 1"OD is best matched with a LED driven at the 500 to 600 mA level. 1.5 to 2 watts seems to be the reasonable ceiling in terms of heat, flux and runtime, IMHO. As the efficacy improves, the power level can remain or even drop depending on the target balance of flux/run.
    Build Prices .... some mods and builds (not 4 sale) "Nature can be cruel- but we don't have to be."~ Temple Grandin

  30. #30
    Flashaholic* Frenchyled's Avatar
    Join Date
    May 2002
    Location
    Land of Cheese, Frogs and wine
    Posts
    2,299

    Default Re: McLuxIII-T (titanium) **SOLD**

    I don't yet know if mine warm more quickly than my PD, but I'll let you know as soon as I'll received it
    Another stupid question Don, please Bernie don't reply Is RC123 use possible in the McLUXX III TI ? I think it's yes....but maybe more current ====> more heat ??

Page 1 of 4 1234 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •