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BBSHD too hot? - before it's powered up???

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    #16
    A little more about the CPU coolers.
    They're called heatpipe coolers, and while gravity does help, they can be run in a horizontal position and still work. There are also vapor chamber coolers that work in a similar fashion but are shaped like flat plates with fins on the hot side.
    They're mechanicaly simple but the operation is fairly complex.
    They operate on the principle of Phase Change. This is what Freon does in an AC unit. It chnges from liquid to gas and back again. In Freon systems the pump allows cooling below ambient temperature. Heatpipes can't do that.
    The hot end absorbs the heat and boils the liquid inside the tubes. This absorbs a lot of heat and tranfers it at the speed of sound down the pipe to the condenser fins. When it condenses to a liquid it's carried back to the hot end by capillary action in a wick, or knurled grooves inside the pipe. The capillary action still works without gravity assist.
    You may be wondering what magic fluid they use inside of these things. Some times alcohol, or acetone. But usually it's just distilled water. By placing a vacuum inside the tube the water can be made to boil at any desired temperature. The vapor chambers are flat with fins on the cold side, but work the same way. They can be found on high powered video cards, and server CPU coolers where space is limited.
    IDK if it would be possible to bend a vapor chamber around a motor and have it still work. A mesh wick, or knurled one might work, but some of them use a sintered coating that would probably break off inside.
    if anyone wants to get serious about motor cooling a vapor chamber that's made to fit around the motor would be the way to go. As far as color goes you should actually be looking at Aluminum vs. Copper fins.
    Most CPU coolers use aluminum fins that are nickel plated to avoid corrosion and allow soldering to copper tubing. The vapor chambers tend to be bare copper. Aluminum is light and cheap, Copper is heavy and expensive plus harder to machine.
    As a computer overclocker the interface between the cooler and heat souce is very important, and less is more. Less air pockets, less thermal compound. A flat polished metal to metal surface with the thinnest wet interface is best. Some Thermal Interface Materials (TIM) are phase change also. Some overclockers remove the metal cover and solder the cooler directly to the bare CPU chip itself. There are some metal solders that melt at around the boiling temperature of water.
    A high end solution would look like a motor with the outiside machined smooth and a cylindrical copper vapor chamber shrink fit and/or soldered onto it with a Silver infused TIM material or low heat solder. As a custom solution it would be expensive. In a manufacturing scenario it might be worth doing for a high end product. Perhaps a miltary application. The TSDZ2 could sure use some help in this area.
    For a DIY project a piece of skived copper finned heatsink could probably be bent around a motor to add cooling fins. Soldering would be an option I think. You would need a solder than melts at a temperature where te magnets are safe, and use an oven to limit the temperature when soldering.
    https://www.ebay.com/i/223533541881?chn=ps
    These can have a black oxide coating applied but it's mostly for looks.
    Looking around I found that OZ e bikes sells a heatsink for the Cyclone motors.
    http://www.oz-ebikes.com/Spares_upgrades.htm
    Heat pipes are good for moving heat to an area with better airflow, vapor chambers spread heat from small component to larger coolers. For an electric motor an extruded aliminum keatsink, or skived copper heat sink that wraps around the motor would probably both be good solutions.
    Last edited by Retrorockit; 05-30-2019, 09:46 AM.

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      #17
      45C yesterday and did ~15mi into nasty headwind running 500W continuous after parked for 2.5hrs in direct sunlight... definitely too hot to touch even before the ride!

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        #18
        Just completed my first build today it's a Soul Beach Cruiser with a BBSHD (1000W) with a Luna Ludicrous Controller and a 52V 14.5 Amp Battery. Did a plug and play with no special programming cable or knowledge. She jumped and ran fairly strong from the start but during my 2 mile test run the power cut out 4 times. It restarted immediately after hitting the start switch but that was the first clue somethings wrong. I brought it back to the house bumming out due to ignorance (lack of knowledge) and parked it in my kitchen. I reached down and touched the motor and it was hot as hell almost burnt me. It's not toasted yet but definitely on it's way. Can anybody help me with advice? Other than consult a professional? Is anyone out there hip to what to check out or what the malfunction could be? It's too sweet a ride to tear up the first day!

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          #19
          Were you lugging it

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            #20
            I was running it hard, heck yea! Paxtana I sent you a new question today please respond! Ken

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