Thermal compound when assembling V6

Discussion in 'E3D-v6 and Lite6' started by doughadfield, Oct 22, 2016.

  1. doughadfield

    doughadfield Member

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    Hi, I'm about to build a Prusa i3 Mk2 kit and, being an electronics engineer, it occurs to me that a light smear of heat transfer compound (the kind I'd use on power transistors) around the heater and thermistor of the V6 hotend may assist with thermal coupling. Is this a good idea, or are there reasons not to do this?

    thanks

    Doug
     
  2. mike01hu

    mike01hu Well-Known Member

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    Not good, as those heatsink compounds break down at the temperatures the nozzle can reach. The mechanical contact is good enough for the heater block but do use the compound in the heatsink to ensure good thermal coupling between it and the thermal break thread but NOT on the heater block threads.
     
  3. dc42

    dc42 Well-Known Member

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    Some people use copper grease on the threads into the heater block. This is intended for high temperature applications such as spark plug threads. I understand it is designed so that the grease burns off, leaving the copper behind. I haven't tried it myself yet.
     
  4. Henry feldman

    Henry feldman Well-Known Member

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    The thermal paste I've been using is rated to a higher temp, but not obviously as high as that spark plug paste above...
     
  5. Spoon Unit

    Spoon Unit Well-Known Member

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    I made the mistake of adding thermal paste into my heatblock when I first fitted my hot ends. The thermal paste ended up going completely black and made it a sod to remove the nozzle and heatbreak. I was able to clean it all up in the end. Completely my fault, the instructions don't tell you to add it, and at the time, I'm not sure they explicitly recommended against it, so I just applied thinking of adding thermal paste to a CPU. You live and learn :)
     
  6. mike01hu

    mike01hu Well-Known Member

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    The trouble with copper-slip is that the grease does burn and leaves a deposit. Spark plug thread temperatures are actually relatively low due to being coupled closely to the cylinder head.
     
  7. mike01hu

    mike01hu Well-Known Member

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    The trouble with copper-slip is that the grease does burn and leaves a deposit. Spark plug thread temperatures are actually relatively low due to be coupled closely to the cylinder head
     
  8. Henry feldman

    Henry feldman Well-Known Member

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    So far the Arctic MX-4 Thermal Paste for me has not broken down with high temp plastics (although I haven't tried Bluprint again, but with 235C is going strong)
     
  9. Spoon Unit

    Spoon Unit Well-Known Member

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    Sounds good. I have a feeling I used the supplied paste. In any case, since removing it, I never noticed a problem with the hot end heating, so I'm resigned to leave it out from this point forward unless there's a good argument for putting it back in.
     
  10. doughadfield

    doughadfield Member

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    Wow guys, thanks a lot for all your wise replies. I'm SOOO glad I asked the question here, before just going ahead and doing it. I'll follow an "if it ain't broke, don't fix it" approach to the printer build, now I've read this thread.
    Thanks again to all who replied.
    Doug
     
    mike01hu likes this.

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