A6063 Heat Sink Modification?

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Hi Everyone, I have to modify this heat sink. It's made out of A6063 and fins are .037" thick and 1.338" tall. I need to cut 3 columns of fins off then in 4 other places along the edges there needs to be some small spot faces for bolts that will require machining 2 fins away at each location. How do you cut fins away without damaging ones around it? my co worker thought slit sawing but sadly with the size constraints of only cutting two fins out without touching those around it doesn't allow for that. My only guess for now would be to maybe slowly ramp down on top of each fin individually with an 1/8" end mill. Or go full depth (which is .004" into the surface the fins come from) and just slowly cut the whole fin away at once. Anyway I am totally at a loss since I have never done this before. Sadly I have no extras so I thought I might seek some expertise here before mangling one and being short for the order right out of the box.

[Aaron Eberhard]

I've done stuff like this (not exactly this, of course) by dipping it in wax to make it a pseudo-solid, first.  Then, when you're done, heat it up to melt the wax away.  Grab some machinists wax and get the best pot out of the company kitchen!

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My coworkers are hopeful they will just be able to rip them off with needle nose pliers. Seeing as we have no extras I just hope they are careful. Since 3 whole columns have to come off they should be able to get some practice on that side. I just worry how easily .037 of 6063 is going to break off and whether they can keep it isolated enough not to damage the other fins. I appreciate the wax idea I don't know about dipping 15 of these in wax...If it was only 5 or less I could definetely see doing that. I sure hope there is another way without wax though. I'll post back when I see how the pliers work out

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So great news if you just bend the tiny fin back and forth 100 times it snaps off

[AHarrison1]

13 hours ago, [email protected] said:

So great news if you just bend the tiny fin back and forth 100 times it snaps off

Only 100... seems reasonable

[Seedy steve]

u could modify an end mill into a woodruff shape to eliminate chatter.  if u leave .1" or less of tooth at the end it should cut well.

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The woodruff cutter is a good idea...but I was exagerating on the 100 really more like 20 to 30 times.