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New PSU for my rostock max killing my fans!

Discussion in '3D printers' started by Jestah, Apr 1, 2014.

  1. Jestah

    Jestah Veteran
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    So after adding a 6mm aluminum heat spreader to my rostock max I decided a BIG 18v psu would help me get it to temp faster....

    Totally forgot that this also feeds far to much juice to my fans and may explain why i have killed a small stack...

    Option 1) run two psu.... PITA.....

    Option 2) Run two 12v dc fans in series from the 18v supply.....

    I would rather go with option two as I feel more peek cooling with help with with my poor retractions and also saves having to install a second 12v supply...

    Any one see a downfall to running with option 2?
     
  2. Tweakie

    Tweakie OpenBuilds Team
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    Perhaps another option would be to use a 12Volt regulator, 7812 or similar (on a heatsink) to drive your fans from the 18Volt supply. :)

    Tweakie.
     
  3. Jestah

    Jestah Veteran
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    Thanks for the idea @Tweakie and I was just about to head to the shop to pick some parts up but using a regulator would negate any fan speed adjustment I have as it would hold the fans at 12 regardless of the power input.

    OR should a peek fan be on full blast all the time?
     
  4. Jestah

    Jestah Veteran
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    Or by feeding the 12v into the rambo from the reg it should then adjust the fan speed via PWM on the Rambo ?
     
  5. Robert Hummel

    Robert Hummel Custom Builder
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    I believe the 7812 IC is only rated for 1.5 amps with a heat sink, if you require more amps look at the LM350t
    It is rated at 3-5 amps I believe and is adjustable
     
  6. bobt

    bobt Veteran
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    JustinTime - You are right about the noise from cutting but the noise from squirting hot plastic is more of a "Sploosh" or a "Splat" as to a "RIP,WHINE or SCRAPE" noise from a mechanical cutter. So Fan noise can be a real annoyance when using a 3d-printer.

    Bob
     
  7. Robert Hummel

    Robert Hummel Custom Builder
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    If you are simply running the fans and want variable speed then just use the LM317 and adjust your pot for speed control ;)
    Simple, easy, cheep
    image.jpg
     
    #7 Robert Hummel, Apr 3, 2014
    Last edited: Apr 3, 2014

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