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Where to get a custom heatsink for my light controller projec?. — Parallax Forums

Where to get a custom heatsink for my light controller projec?.

ke4pjwke4pjw Posts: 1,181
edited 2010-11-16 20:02 in General Discussion
I need to have a heatsink fabricated for my light controller project. I just need a piece of folded aluminum with holes drilled in it. (One piece that goes under the board and uses it as a mount also)

Any recommendations? Any ideas on the cost of such a thing?
75886_1730868078480_1441831958_31851277_3987897_n.jpg
720 x 540 - 89K

Comments

  • Jay KickliterJay Kickliter Posts: 446
    edited 2010-11-15 05:49
    What's the approximate size, and how many do you need?
    ke4pjw wrote: »
    I need to have a heatsink fabricated for my light controller project. I just need a piece of folded aluminum with holes drilled in it. (One piece that goes under the board and uses it as a mount also)

    Any recommendations? Any ideas on the cost of such a thing?
  • kwinnkwinn Posts: 8,697
    edited 2010-11-15 07:03
    You could do it yourself relatively easily, and signing up for an evening adult ed class in sheet metal at a local school would give you access to the equipment.

    Any sheet metal shop should be able to do that. No idea of cost but should not be that much.

    PS - Do make sure the triac/scr/etc. tabs are isolated from the heat sink if they are not internally isolated.
  • LeonLeon Posts: 7,620
    edited 2010-11-15 08:07
    When I needed a heatsink for a PCB I designed I made one from a suitably sized piece of Al channel that a local shop cut for me. I just had to drill a few holes in it.
  • tonyp12tonyp12 Posts: 1,951
    edited 2010-11-15 08:34
    By 12" for $1.62
    http://www.onlinemetals.com/merchant.cfm?pid=1061&step=4&showunits=inches&id=297&top_cat=60
  • electrosyselectrosys Posts: 212
    edited 2010-11-15 08:49
    There are 16 X Triacs, maybe you have to consider to install a little fan as well.
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2010-11-15 09:02
    It's too late for this board, it looks like, but in the future be sure to solder the heat-sunk chips after they've been attached to the heatsink. The reason is that attaching them after soldering creates stress on the already-hardened solder joints, which may cause them to fail down the road.

    Also, for your board, I would not use a single U-shaped piece of aluminum but, rather, two separate pieces. The reason is that the U-shaped aluminum will expand as it warms up, widening the distance between the sides which, again, will put stress on the solder joints.

    Finally, for the reasons stated, you should not support the extrusion solely by the legs of the parts you're trying to cool. It needs to have it's own physical support.

    Why not just buy some channel extrusion with fins for each side?

    -Phil
  • tonyp12tonyp12 Posts: 1,951
    edited 2010-11-15 09:51
    Using the metal case or mount as a heatsink is OK idea
    http://www.onlinemetals.com/merchant.cfm?pid=1015&step=4&showunits=inches&id=63&top_cat=60


    But Next time, design the pcb with some like this in mind.
    http://www.goldmine-elec-products.com/prodinfo.asp?number=G2109
  • LoopyBytelooseLoopyByteloose Posts: 12,537
    edited 2010-11-16 08:37
    I have aluminum material that us used to support a bank of modular relays, fuses, and circuit breaker. This is sold at electronics supply houses everywhere. If it is adequate as a heat dump, it can be cut to length and the holes are really long slots that may line up quite well.

    The problem with custom fabrication is you really don't get a 'wonderful' per unit price until you order 10,000 units at one time.

    Another alternative is just aluminum bar stock cut as required and drilled at the appropriate interval, maybe tapped as well.

    If you must have the fold, visit an aluminum supplier and try to find an existing extruded shape (an angle or el) that fits your needs - then just cut to length with a 'chop saw' and drill holes on a drill press. I suspect that it is both easier to get done and will actually cost less than having someone bend flat stock.
  • ke4pjwke4pjw Posts: 1,181
    edited 2010-11-16 20:02
    Thank for all the replies! I ordered custom cut sheets of .05" 5052 aluminum from onlinemetals.com. I believe it will be malleable enough for me to bend it myself with a jig.

    Hope it works out. I will keep you guys posted.

    --Terry
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