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Milling bevels and through-holes in a large heatsink

Posted: Tue Aug 16, 2016 10:23 pm
by Brian Stone
Thought I'd post this, since it's sort of the first big chunk of aluminum I've milled on my S2. I've done some smaller aluminum projects in 6061 bar stock, but those were just simple experiments that didn't really teach me how to mill aluminum.

A friend of mine had a large heatsink (about 8" square) that required modification and mounting holes drilled. I offered to do the job on my S2 for the extremely generous price of one beer. Here's the result.

RPM: 20,000
MILL: 1/4" 2-Flute Square

45 degree bevels --
Feed: 1200mm/min
DOC: 0.25mm

Ratchet clearance helical bores --
Feed: 800mm/min
DOC: 0.25mm per helix revolution

Through hole helical bores --
Feed: 300mm/min
DOC: 0.1mm per helix revolution

The through holes were milled in 2mm depth increments though 7.5mm total thickness. After each increment the end mill was raised to clear chips.
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Incidentally, the beer was excellent and more than adequate compensation.

Re: Milling bevels and through-holes in a large heatsink

Posted: Wed Aug 17, 2016 8:00 am
by zerblatt007
Nice!
Was it difficult to hold it down securly?

Re: Milling bevels and through-holes in a large heatsink

Posted: Wed Aug 17, 2016 4:30 pm
by Brian Stone
Not difficult at all. I used just a few strips of double-sided foam tape.