Resistor Bank Heatsink

!!!  Warning: if you are using this you are probably doing something dangerous and should proceed with caution !!!

Ever need to test a fuse to see if it will pop under the expected load? I designed this setup to do just that. It's more of a temporary test bench setup than something that would be permanently installed but it should provide adequate cooling for most use cases. This setup works with up to six 100 Watt (60mm long asymetrical mounting) wirewound resistors.

Hardware:

• One 150mm x 50mm heatsink
  • This was designed around a 150x60x18 style (amazon) that currently hard to find.
  • It should also work decently currently more common 150x60x15 style (amazon) but you'll be tapping into the sides of fins instead of between them.
• Two 60mm x 20mm PC fans
• Four M2.5 x 10mm socket head or button head cap screws
• Four M4 x 25mm or 30mm flat head cap screws (button head might also work)
• Four M4 hex nuts
• Twelve M3 x 6mm socket head cap screws (button head might also work)

Assembly: 

• Print two brackets.
  • No special notes for printing.
  • I printed mine in ABS but if you're running hot enough to weaken PLA or PETG something has likely gone wrong.
• Drill (2.5mm) and tap (M3) twelve holes into the face of the heatsink.
  • Features of symmetric. See uploaded sketch for details.
  • Two rows of six holes 8mm from long edges and 44mm spaced.
  • Space holes from short edges at 4mm, 28mm and 52mm respectively. 
    • or 4mm from edge and 24mm between if you prefer.
    • There will be a larger (46mm spacing in middle)
    • repeat on other side.
  • Approximately 6mm deep for each.
  • Yep… drilling and tapping into heatsinks is an unpleasant task. I know your pain.
• Drill (2mm) and tap (M2.5) in the outer gaps between fins on both short sides.
  • Holes should be approximately 13mm from the tips of fins and 55mm apart.
  • Approximately 6mm deep for each.
• Press M4 hex nuts into slots of brackets.
  • Just start them if it's difficult. The screws will snug them in later.
• Attach one bracket to each fan using M4 screws.
• Attach brackets to short sides of heatsink with M2.5 screws.
  • tips of fins should rest on ledge of bracket.
  • If holes don't line up feel free to embiggen the holes in the bracket.