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New surfacing tools are nice

billy2billy2 Member, OS Professional, Mentor, Developers, User Group Leader Posts: 2,005 PRO
edited May 2023 in General

Here's the newest version of a BMW tail light assembly using Onshape new surfacing techniques. Is it worth it?


I think so.


I'd like to thank @S1mon for hounding Onshape so they'd clean up curvature combs making them useful. 


Curvature combs used to create the main surfaces:


«1

Comments

  • lanalana Onshape Employees Posts: 688
    Looks really nice!

    +1 on Thank you @S1mon

  • billy2billy2 Member, OS Professional, Mentor, Developers, User Group Leader Posts: 2,005 PRO
    Thanks lana

    Can a tail light on a motorcycle be too bright?


    60% of accidents between motorcycles & cars, the car driver say they didn't see the bike.

    So the answer is no, light'm up and make'm visible. My new light is 21 watts.

     
  • adrian_vlzkzadrian_vlzkz Member Posts: 248 PRO
    Nice work Bill!
    Adrian V. | Onshape Ambassador
    CAD Engineering Manager
  • billy2billy2 Member, OS Professional, Mentor, Developers, User Group Leader Posts: 2,005 PRO
    Thanks Adrian
  • nick_papageorge073nick_papageorge073 Member, csevp Posts: 619 PRO
    Nice surfacing!

    Off topic, if you’re looking for a diffuser material to hide the individual LED’s, I have a great source I’m using for two light subs on my production project. 

     
  • billy2billy2 Member, OS Professional, Mentor, Developers, User Group Leader Posts: 2,005 PRO
    @nick_papageorge073 I'd like to see your diffuser material. I've PM'd you my login, can you share with me?
  • nick_papageorge073nick_papageorge073 Member, csevp Posts: 619 PRO
    billy2 said:
    @nick_papageorge073 I'd like to see your diffuser material. I've PM'd you my login, can you share with me?


    yes, I have a video too where you can really see how well it works, without the auto white balance of the camera lying to you. I must have tried 20 different materials and nothing was even close. I’m in Peru on vacation. Will dig up video and send later. The material is from luminit.com. My company hired a lighting engineer consultant a couple years ago and he turned me on to it. This is the exact one:





  • billy2billy2 Member, OS Professional, Mentor, Developers, User Group Leader Posts: 2,005 PRO
    I've ordered a sheet, they look great and will take a look.

    These are my current lenses:


    I'm currently using the clear lense. Typically the use case is a viewing distance of 10 meters and individual LEDs are hard to distinguish. The other issue with my use case, they get dirty fast. The rear tire is throwing dirt on to the light all of the time and I'm constantly cleaning them.

    Have fun on trip and please send video on return, sounds interesting.


  • steve_shubinsteve_shubin Member Posts: 1,061 ✭✭✭✭

    @billy2

    Billy, I’ve been interested in your tail light development. Really like how you’re able to get such a good fit using your scanner

    But I got to wondering about something

    A little after it got dark, I noticed my neighbor had his new Tacoma out in the street with the hazard lights on.

    So I went out there to get on axis with those rear blinking lights.

    At 70 feet directly behind the truck, the red tail lights were easy to look at. Not much of an output on that vehicle’s hazard lights

    Now the thing that I started to wonder about, was that I was curious to know how auto lights compare with one of the newer flashlights. So I figured I’d get one of my flashlights to see.

    The light I chose for my test, an Olight Marauder Mini, has one white LED for spot. Six white LEDs for flood. One red LED. One green LED. And one blue LED. And this light has TIR optics

    Using the single red LED only for this test, I turned it on to the high position and walked out to a distance of 313 feet

    That flashlights single red LED was monstrously brighter at 313 feet, than the Tacoma was at 70 feet. I figure that single red LED with its TIR optics might be effective out to 500 or 600 feet or maybe even more. But because of the bend in the road, that was as far as I could get for the moment

    I also got off axis with this single red LED by about 11° and it still was effective. Not as effective as when viewing it more on axis, but still very effective. I would’ve tried to get off axis more, but the vegetation didn’t allow.

    Now Olight — the maker of that flashlight, has not published the make of the LEDs

    But there is some speculation that the colored LEDs might be Osram

    So I was curious to know if you had tried any Osram LEDs

    Here’s an article that speculates on the make of the LEDs

    Flashlight Review: Olight Marauder Mini


  • steve_shubinsteve_shubin Member Posts: 1,061 ✭✭✭✭

    Here’s the weird thing, in that article in the link up above, it says that the red light is in the orange red area (620nm)

    And on the highest setting, the flashlights red LED only puts out 200 lm.

    If you go to the Osram site, most of the red LEDs near the 200 lm range are between 2.6 to 4.2 watts

    Which makes me think that if you had your 23 watt inside of a similar TIR that this flashlight has, I’d probably be able to see it VERY WELL at a half mile

    Or there’s something that I clearly don’t understand about how flashlights work. Because if that little LED in this light is only around three watts or so, why is it so doggone bright to the point of my not wanting to look at it for very long when on axis even at 300 feet.

    Mind you, that the TIR may have a bit of throw to it. But it does have some spread also. If you look at that article above, you can see the guy shining that light out in the woods.

    So what’s going on here ???

    Hardly any watts and bright as all get out.

    Stumped


  • steve_shubinsteve_shubin Member Posts: 1,061 ✭✭✭✭
    I think things are starting to come back to my old mind. LOL

    https://budgetlightforum.com/t/my-understanding-of-emitter-die-size-in-relation-to-throw/48831

    But even if the combination of smaller chip to TIR in this flashlight does have some throw. It still does have some bit of flood and you could tell from the pictures in the first article.

  • billy2billy2 Member, OS Professional, Mentor, Developers, User Group Leader Posts: 2,005 PRO
    edited May 2023
    @steve_shubin

    I'm lucky to have lived through the time when LED's were replacing HID lighting and have designed many light conversions. I got tired of an inconsistency light output lux vs. lumens so I started using watts to compare LEDs. That's the common denominator for me, it's probably not a good way to pick bright LEDs but one thing for sure the brighter the light the hotter it gets. I also have to make sure things don't catch fire so tracking thermal is a good thing.

    Your light is a different problem, it's a focused light, running on limited power and not running through a diffuser. I have unlimited power but have to worry about thermal loads. You can't hold my lights when they're running. I'm trying to emit a ball of light and when you're beaming. I'm trying to run in daylight and be seen. 

    Focusing the beam and trying to get a flashlight to shine for 2 miles is tricky because the source from an LED isn't a point. Parabolas work off a point source. Smaller LEDs have 1mm x 1mm source, the one I use has 4 of these so the size is 4mm x 4mm. The optics is a mess and I pick one from the supplier. I'm not sure I want to focus the beam but would rather want the flood effect covering 120°. My tail light doesn't create a pretty prenumbra which is how we judged our focused light. We were looking for a tight transition between light & dark when shining a beam on a wall, it wasn't scientific at all.

    I'm using a Luxdrive which is the brightest led source I can find at this time:




    This is a single Luxdrive with 19mm aperture.


    I've followed this bike on an interstate and you do see it amongst all the other car lights on the road. It's not too much and I have it tuned to about a 1w running down the road. When I hit the brakes, its 9w. You do see a difference.

    Look at the end of the handle bar, this is where the British have started to put their turn signals, it's legal over there. These are Kuryakyn lights from a well known bike parts manufacturer. You can't see them on the road. They work great when you're in a garage.



    There's a lot of crazy guys out there building motorcycles. 



    There's starting to be a buzz that LEDs on motorcycles aren't bright enough, it's not just me.
     
  • dirk_van_der_vaartdirk_van_der_vaart Member Posts: 525 ✭✭✭
    Not only on motorcycles, in bright sunlight you see a lot of new car's with very poor light's.
    And it's not only how much Lumen the light is it's also about spreading the light trough a diffusor, mostly an acrylic molded piece.
    Here an example of very bright led's
    https://nl.aliexpress.com/item/32827569920.html
  • billy2billy2 Member, OS Professional, Mentor, Developers, User Group Leader Posts: 2,005 PRO
    edited May 2023
    @dirk_van_der_vaart

    I use that style of led on forward signals. They are bright and it's hard to see the individual LEDs. China is producing amazing LED products. 



    The LEDs I buy are flat strips and I heat them up and bend them around the upper fork tube. They are bright and it's hard to see the individual led through the diffuser. I buy a lot of LEDs these days looking for the next technology. I focus on the spreader, the aluminum backer that the LEDs are mounted to. I have to have this to dissipate the heat. Optics are one thing, but LEDs are a mechanical problem, how do you manage the heat. Newer motorcycles are shipping with larger stators because everyone is wearing heated gear and bikes have to create more electrical power. Heated grips, handlebar heating takes up more power than all the LEDs on any of my bikes. A bike has plenty of power to run LEDs.

    I called the diffuser company that @nick_papageorge073 told me about and spoke to them for over an hour about lighting up bikes. What a great company and I bought a bunch of stuff which hasn't arrived yet. Their diffusers, you lose very little brightness because their crystals are magical. I have no idea the physics behind the diffusers they make.

    I'm excited about these new diffusers which will probably prompt a new version of lighting for my motorcycles.

    I'll post how these new diffusers perform after they arrive. 


  • nick_papageorge073nick_papageorge073 Member, csevp Posts: 619 PRO
    @billy2, I just sent you an email. Hope it's helpful! Nick.
  • steve_shubinsteve_shubin Member Posts: 1,061 ✭✭✭✭
    edited May 2023

    Heat

    Yup. Definitely an issue.

    It was an issue when I was using my Nightsun xenon mountain bike set of head lights back around the latter part of the 80s. Could not use the high beam without moving. Had to have air passing over that light.

    And for us folk that like our HANDHELD lights (flashlights), it can be an issue with us.

    Some of the reviews on various high-powered flashlights will tell you that you’re going to have to use a glove if you use such and such a light for an extended period of time

    Some of the brightest lights have fans built-in. In fact, the one that is at the top of the heap right now, has an intake fan blowing across a radiator, and an exhaust fan on top of that.

    Go to the two minute mark of this video to see what handheld is capable of —

    https://www.youtube.com/watch?v=ZUOs_JNd0_E

    So yeah, heat is that problem

    But after viewing my single small Red LED at over 300 feet at night, and having tested it out to over 140 feet during the day, I’m pretty sure an array using TIR optics, splayed similar to your setup would be able to get the job done.

    I would’ve tested it to further than 140 feet, but I was doing this in the yard and it was kinda inconvenient to get further

    BUT BUT BUT — I could CERTAINLY understand that designing an optimized paraboloid to work with the tiny emitters may not be the easiest thing to do.

    The reason why I’m kind of elated with this idea is because if we’re talking about using five emitters at about 3-1/2 watts per, we’re talking somewhere around 18 watts total. But I don’t know if you’d even be running it anywhere close to that for braking. For other than braking, the watts are going to be way less. Which makes me think that heat might not be such an issue if someone were able to get this type of design to work in a tail light. Just a thought.

    Seeing you’re interested in the next of technology, keep an eye out for the LEP lights. The laser excited phosphor lights.

    Now these laser excited phosphors are not the same as looking at a laser light because It is actually the light of the excited phosphor that is being projected

    At the first link below, you may have to scroll down until you get to — 

    Questions about LEP flashlights

    https://1lumen.com/lep-flashlight/

    Guide to LEP Flashlights

    Right now they’re being used only for extended range spotlights or throwers. And they do throw a tremendous distance. But I was reading how one of the makers of these lights, is trying to develop a wider spread. More of a flood.

    Granted it’s going to be way too bright as is. But if a flood version is ever developed on top of possibly pairing it with that crystaline like diffuser used on those COB LIKE lights that Nick brought up, you’d probably be able to crank this thing way way down and still get amazing light

    And cranked down far enough would make me think — not much watts

    Here’s a video of a LEP in action 

    https://www.youtube.com/watch?v=1Pwogzi_nCc


  • dirk_van_der_vaartdirk_van_der_vaart Member Posts: 525 ✭✭✭
    Here is some information about different sort's of diffusors
    https://shop.pyrasied.nl/product-categorie/lichtdiffusers/
  • billy2billy2 Member, OS Professional, Mentor, Developers, User Group Leader Posts: 2,005 PRO
    edited May 2023
    @steve_shubin I've spent the morning researching LED's based on your suggestions. 

    -I'm using a cree xpE2-red which is 201 lumens. It's good for me because it comes mounted to an aluminum substrate. 
    -I've looked up cree xhp series which are white and very bright. I only found individual LEDs meaning I'd have to design the spreader which I've done in the past, but currently not really interested in doing that. 
    -LEPs are scary (lasers), these would be illegal to have on a motorcycle. But I want one.

    It'd be fun to take a ms18 (uses a cree xhp) apart:
    -I found a video and this might be the spreader

    This looks like a copper substrate which is better than aluminum. More expensive too.

    -I also found a heat pipe article

    You can get 10x-100x heat flux improvement over solid copper. They said in a video they're pulling heat from the spreader with a heat pipe.

    Then they use a fan & forced air which is the worst part of the thermal path. The packaging is really interesting but I can't find one disassembled, infact, I found references to them being destroyed to take them a part. At $700 bucks, I'm not that curious.

    @dirk_van_der_vaart
    I went through their website and will order some cylinders. These would be easy to incorporate into a design. I like that they have a thermal forming material which could easily turn into a limited production run. 

    I'm still not understanding why acrylic is better than polycarbonate? Most plastic lens are PC on bikes for durability. Can you read their website? I'm not opposed to acrylic if it's a better diffuser.

    @nick_papageorge073
    I didn't get an email. It's my fault, my rndengineering server uses a "let's encrypt" certificate which expired and I need to reboot the server. This is my problem and I sent you my current email in a PM update. I need to update my Onshape login so everything works.


  • steve_shubinsteve_shubin Member Posts: 1,061 ✭✭✭✭
    edited May 2023
    @billy2

    Like you Billy, I thought LEPs weren’t in the car world, because those pencil beams would create havoc. I thought they were primarily the realm of flashlight junkies

    Then I read how autos were one of the first with LEPs

    Some crazy company named BMW pioneered their use on cars, and that they worked with Osram to make it happen

    The article below says that they’re four times more powerful than LEDs.

    Laser light for headlights: latest trend in car lighting | OSRAM Automotive

    Evidently they figured out how to make them more than just a pencil type of beam, that is, if they’re using them for headlights.

    I wonder how they’re dealing with heat on these things. How about these lights when they’re sitting in traffic and not going anywhere at night. And there’s no wind movement over them.

    Maybe it’s because the LEP is not confined to an enclosure with these headlights. Maybe part of the LEP is exposed on the backside — on the engine compartment side to where that heat is able to escape into the engine compartment.

    Be interesting to go find one of these cars, pop the hood, and see what can be discovered about these lights

    All the LEPs I see being manufactured right now are white light. But a paragraph from one of the articles in one of my above posts got me to thinking that there can be such a thing as red light LEPs

    Here’s that paragraph —

    A Note on Efficiency

    One thing that sets LEP lights apart is the incredibly high efficiency of their emission, requiring less power for more light than other sources. This is due to the utilization of blue light. The typical drive current required to produce desired light intensities in blue lights is 4.2 mA, as opposed to 8.8 and 10.5 mA in red and green lights respectively.

    Then I found an article where it talks about europium-containing red-emitting phosphor

    Laser excitation of red, green, blue and trichromatic white rare-earth phosphors for solid-state lighting applications - ScienceDirect

    I’ll take some time later to read the rest of this article

    I might take a little time to see if there’s red LEPs being marketed right now

    And going about it a different way. Here’s a guy using filters for color and he’s also getting a larger beam with a diffuser on his LEP

    https://www.youtube.com/watch?v=LUEuZ848jp8

    Addendum —

    So if there is such a thing as a red LEP, and if it is powerful, then the idea is to turn it down. And along with what has been discussed – start with something that’s bright, but turn it way down so you’re using less watts, and as you’re limiting the watts, you’re cutting the heat way down


  • billy2billy2 Member, OS Professional, Mentor, Developers, User Group Leader Posts: 2,005 PRO
    @steve_shubin

    Wow, laser lighting. It's the future. That OSRAM BMW headlight will shine 600m. How can that be legal?

    I found these guys, baja design, I've used their stuff for off roading in the past. California law states that these type of lights have to be covered when driving on a public road. There's a lot of crazy people riding around in the desert at night.

    $13 red laser on amazon:


    This is a class 3a laser, the same a laser pointer, even though it's low powered, I don't think you should be pointing it at someone. I'm still looking for a red laser with flooding optics. I think this could be the future.

    Heat wouldn't be a problem in car. Conduction is the best way to move heat and you can use the car's body as a radiator. Even if the car is parked, there's enough surface area to allow convection to dissipate the heat. Cars are huge, lot's of surface area. You do have to worry about the source point and getting that to spread quickly. We called this the spreader, a small piece of copper or silver, and then to aluminum and then steel. We would use small pieces of copper and then an aluminum heat sink to maximize thermal flux. It does help.

    The LED's I buy goes straight to aluminum without any copper, but it's also cheap. They're also on Bergquist boards, they'll only last seconds if you light them up without a heat sink. I'm sinking them to the motorcycle frame.

    Seems to be working:


    The yellow is the rear fender.

    The thermal compound is problematic in that it dries up over time. Do you know of any compounds that'll last the test of time outdoors?



     Thanks again for all the info, I have several new designs brewing in my head.




  • steve_shubinsteve_shubin Member Posts: 1,061 ✭✭✭✭
    edited May 2023
    @billy2
    The thermal compound is problematic in that it dries up over time. Do you know of any compounds that'll last the test of time outdoors?
    Maybe these guys would know of a company that makes thermal compounds for outdoor use. The link has English translation available

    https://www.thermal-grizzly.com/

    Take a look at this video. It was made in 2019 so it’s maybe not latest or up-to-date. Nonetheless, it does seem to have some good info. —

  • billy2billy2 Member, OS Professional, Mentor, Developers, User Group Leader Posts: 2,005 PRO
    edited June 2023
    @steve_shubin, @nick_papageorge073

    I received a diffuser from Luminit and ran some tests. I'm running at a lower 9.6 watts to prevent the unit from reaching melt-down temperatures during bench tests.

    Here's the rear light without a diffuser at 9.6 watts:

    These are hard to look at straight on. The camera doesn't capture the intensity when one meter away. Nobody should ever be that close when out in traffic, but, it's also not the brightest this light can get.

    The rear light with diffuser material add by leaning film against unit:

    It's still bright and it's easier to look at. You can see the reflection on the table, the red light is more consistent from left to right.


    Here's the thermal output at 9.6w:


    Thermal conductivity for materials:

    air 0.028 W/mK

    styrofoam 0.033 W/mK

    water 0.609 W/mK

    silicon 1.4 W/mK

    artic silver 4 W/mK (says everyone is lying about their conductivity)

    grizzly paste 12.5 W/mK

    grizzly pads 62.5 W/mK

    6061 154 W/mK

    copper 398 W/mK

    silver 419 W/mK


    I've order some grizzly paste & pads and will run a test comparing them to silicon grease. The silicon grease lasts forever but isn't a good conductor. I've tried other compounds and pads in the past but they don't last the outdoor environment and the pads are destroyed if you ever need to work on the light. We'll see how grizzly holds up.


  • steve_shubinsteve_shubin Member Posts: 1,061 ✭✭✭✭
    @billy2

    Observing your work is certainly interesting

    Thanks for that thermal conductivity list

    Now you’ve got me curious to see if the Grizzly products are any good

  • billy2billy2 Member, OS Professional, Mentor, Developers, User Group Leader Posts: 2,005 PRO
    edited June 2023
    @steve_shubin

    I spent most my evening last night reading up on thermal transient analysis trying to freshen up on analyzing a led. Most analysis are steady state but it gets more interesting after you turn the power on.

    IR for adding to analysis
    Thermal transient analysis

    @GregBrown please add, not only thermal to analysis, but include transience, thanks.

    I've finished upgrading my light to the grizzly conductors and it does seem to help. It's not night & day but it is better. The gap that the carbon thermal pad was eliminating was really narrow. I've always been compressing the light pipe to led spreader so the carbon helps a little. I also went to a larger heat pipe thinking the old one was too small.

    Completed LED tail light assembly:



    Thermal profiles, somewhat steady state:

    -there's a 10° rise from LED to heat pipe, not the best but it's a braided cable.
    -the LED power cables are pulling a lot of heat away and I should be using a larger wire to sink more heat


    Thermal at the motorcycle's frame connection point:

    -You can see that the heat pipe is heating up which is what I'm wanting.
    -The last design wasn't doing this


    Added diffusers:

    -you can still see the individual leds, I'm playing tricks with the camera's exposure to make it look fussy
    -I like the diffusers because they soften the light making it easier to look at

    @nick_papageorge073



    FYI- I went to a motorcycle safety class and this is what they think motorcycle lighting should look like:


    Lite'm up


  • steve_shubinsteve_shubin Member Posts: 1,061 ✭✭✭✭
    edited June 2023
    @billy2

    I think because of your design, in that there was not a big gap to fill,  seems pretty obvious that’s why that pad was effective. So yeah, the pad is probably better than other products, but without your design, it likely would’ve been useless.

    So I was thinking about things that I’ve used and I was also thinking about a conversation I had with a good friend

    If the air is not moving, if it’s just sitting there stationary, no doubt it’s pretty useless as far as cooling things.

    But if there is extensive heating that needs to be taken care of, it’s the movement of air that cools the item off

    When I had my NightSun xenon bike lights back in the late 80s, we’ll these were the brightest lights you could get at that time.

    One thing that the directions made very clear was that the high beam of this Xenon lighting system was only to be used when the bike was moving. There had to be air moving across that light to cool it.

    Then I’m thinking both of the AC systems here at the house, meaning the typical forced air unit and the split system, both have big fans to cool off the radiators or the condensers

    That huge hundred thousand lumen flashlight had not only an intake fan blowing across the radiator but an exhaust fan also to pull the air across it

    I called a good friend of mine who owns a refrigeration company. Now the type of refrigeration he does is big scale. The large supermarket chains that have the humongous warehouses that are nothing but one big refrigerator. Well that is the type and size of systems he installs and maintains.

    He told me long ago that the coolant that’s used in those systems is ammonia. But in the long run, it comes down to a condenser or a radiator with a big fan on the roof or the side of the building that cooled off that coolant. So again, a fan – moving air.

    At the bottom of this spiel, is a link to a very interesting video that goes into LEDs and the heat problem and different ways of dealing with it.

    In the video, the guy says that all of the brightest LEDs use fans for cooling.

    Another thing very interesting, was the fact that, even if the compartment was a sealed compartment, apparently a fan would still help

    But I think it’s pretty obvious that if you can have an inlet and an exhaust to pull in air from the outside and expel to the outside, that’s going to be better

    There’s a new camera released a week and a half ago. And one of the main features of this camera is the fact that it has a fan. And that fan is one thing that sets this camera apart from every other camera in its price range.

    All other cameras in this price range have limitations on how long you could record in the video mode. Because the cameras heat up and so the system either shuts down, or you have to shut it down. Sounds like some of the cameras will only allow you to record a half hour video and then you have to wait till the thing cools off to use it again

    But this new Panasonic camera will allow for unlimited continuous recording of video. And it’s all because of that fan.

    The camera has an inlet and outlet for the cooling system that is IP rated, and which will protect that expensive CMOS sensor not only from weather, but from dust also.

    I’d be curious to see how it’s done. What type of baffles there are or whatever at the inlet and outlet.

    Maybe there’s a repair manual out there with a schematic of this camera that can be found online ??

    https://amateurphotographer.com/review/panasonic-lumix-s5iix-review/

    Anyway, below is that video I mentioned above


  • steve_shubinsteve_shubin Member Posts: 1,061 ✭✭✭✭
    edited June 2023

    @billy2

    First off — I don’t think this thing looks anywhere near as good as your design. It’s just a straight bar basically. And that straight bar would look flat out ugly on your fender.

    But it does seem to be bright.  I think I read 800 lumens for the brake light and 400 lumens for the tail light.

    There’s a video in one of the comments.

    I’d be curious to see what they’re using for LEDs


    https://www.amazon.com/Morimoto-LED-MC-5TOP-Black-Motorcycle-Universal/product-reviews/B07176JBMV

  • billy2billy2 Member, OS Professional, Mentor, Developers, User Group Leader Posts: 2,005 PRO
    edited June 2023
    @steve_shubin I really enjoyed the HR video, I think the guy is right & really like what he's doing.

    LED designs aren't easy and there's a lot to consider. I'm not a fan of fans (made myself laugh) mainly because it's another source for failure. Air is everywhere and that's why people use it. Inside an enclosure, does the air move? Half the cell phone manufactures say yes and the others say no. Just the assumptions people make is confusing. Cell phones have the heat on the back face because your hand doesn't mind it being warm, your ear does care and doesn't like the heat. Cell phone designers shed the heat off the back face.

    I've used fans, natural convection & conduction in past designs and all have specific requirements. The most fun is natural convection using CFD and the results are always not what you think. I can't tell you how times a design will have fins on the top of a box and you'd be better off just cutting them off and saving weight.

    I worked at night rider, a mountain bike lighting company and my job was to convince the owner to add a thermal cutoff to a light. Turns out 2 mph was enough to cool the light. The problem wasn't when the light was on the bike, it's when someone tries reading a map and sets the light on a table. That stops all air feeding the natural convection and starts a nuclear melt-down or the light just burns out. You can easily add a thermistor which adds resistance/temperature and prevents things from burning up. I must have won, because the lights had one add to the led mounting plate. Thermistors don't fail like a fan will. When you start riding, the light cools down and it gets brighter. No one complained. When you're riding there's plenty of air flow to keep things cool.

    I remember the design of the light housing had an induction vent to allow air to pass to back and cool the LED down. With a high pressure air nozzle, you couldn't force a enough through to make a difference. They left it in the design because it looked cool. Those little fans with those narrow passages through the heat sinks are probably choking the flow seen in the HR video. I remember for natural convection, we had air gaps of 7mm to prevent choking. Air doesn't like narrow passages.

    I have some friends cooling servers with water or coolant. It's a great story.

    https://chilldyne.com/

    The pump runs at less than atmosphere so there will never be any leaks. Server farms are a crazy amount of heat and cooling servers with blowing air is insane. To cool the building that houses the computer's takes more power than powering the computers. These server farms aren't designed very well and my friends are starting to do well. There's always a better way.


    I'm starting to wire up my light and hope to have it mounted in a few days. I'll post a picture when it's done.

  • billy2billy2 Member, OS Professional, Mentor, Developers, User Group Leader Posts: 2,005 PRO
    Finally got the wiring done, at least in cad. It should probably become a pcb:



  • billy2billy2 Member, OS Professional, Mentor, Developers, User Group Leader Posts: 2,005 PRO
    So I re-positioned all the wire terminals and clicked a button and all the cables updated:


    Now I have a good cut list for all the wires:


    Parametric feature based modeling still amazes me.


  • billy2billy2 Member, OS Professional, Mentor, Developers, User Group Leader Posts: 2,005 PRO
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