Heatsink Skiving (2021) [video] | Hacker News Reader

Heatsink Skiving (2021) [video]

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Copper is very ductile (soft) compared to many other metals because it is molecularly arranged in a cubic arrangement, while other less ductile common metals tend to be arranged hexagonally or are alloys of multiple elements. The mono-elemental cubic arrangement has more horizontal planes. Horizontal planes of molecules can 'slip' past each other more easily, and in the electron soup that characterizes metal the bonds between those molecules can more easily "stretch" without breaking. This is why you'll find ceramics with a cubic structure that are brittle and prone to breaking in layers, rather than being ductile. It's also why metals are great conductors!

If you like this kind of stuff, check out introductory undergraduate level 'materials science' course materials! There's tons of lectures and educational content on YouTube and textbook PDFs are bountiful on the net :)

Yep but copper does lose ductility when deformed. When put under enough stress to deform it, it "work hardens." This is why thick copper wires break if bent back and forth too much (and hence why we have multi-stranded wires for applications with movement and vibration), and why crush-sealing washers can't be reused. This work hardening can be undone by heating the copper until it gets red hot, but this isn't practical in many applications.

I was under the impression crush seals are used once not because of work hardening but from deformation. You can only crush them into place once. e.g. on conflat vacuum flanges the harder stainless steel knife edge on the flanges sandwich the copper gasket biting into it creating a tight metal-to-metal seal. That biting plastically deforms the copper forcing it into the tiny surface imperfections in the stainless to form an extremely tight seal. Once you break that formed copper seal it is permanently damaged. It cannot be reused as the mating area has has been deformed and the majority of its material squeezed away from the mating area. You have to start over with a fresh flat seal that will deform into the cracks and crevices.

You're totally right, it depends on the application. I was thinking of oil drain plug washers, which can be reheated and reused many times, basically until they are too thin to do the job.

I usually just sand the washer surfaces flat on some high (600-800) grit wet-dry paper, never had a problem. Works on banjo bolt washers too.

My father was a metallurgical engineer though unfortunately passed away when I started high school. Recently after reading a story on melting iridium in an e-beam furnace I am now finding myself fascinated by metallurgy. One thing that interested me is the seemingly simple yet complex process of vacuum metallurgy where alloying and/or purifying is done in a vacuum using all sorts of exotic heating and handling methods.

Not a metallurgist, but it really seems like zero-g alloys will give us some amazing materials.

https://www.google.com/search?q=zero+gravity+alloy+site%253A...

Users who liked this might also like: https://old.reddit.com/r/ManufacturingPorn/

Industrial or manufacturing processes are so interesting to watch and there are so many details to discover. Separating eggs is pretty interesting imo: they let them run down a v-shaped channel that has a narrow opening between the sides. The egg whites seep through that opening while the yolks run along the channel and are guided elsewhere eventually [0].

Carrots [1] are peeled by moving them through peelers whose blades don't look that different from a usual kitchen tool.

Bottle production [2].

[0] https://youtu.be/bG34uNbe5f4?t=365

[1] https://youtu.be/C1q2sqfQPqU?t=24

[2] https://www.youtube.com/watch?v=A_M8WBJMcM0

Thanks, I just wasted about 29 minutes on this sub watching everything.

No matter how many times I look at the title, even after watching the video, I keep reading "Heatsink Skydiving".

Was disappointed at the lack of skydiving, but skiving was cool too I guess.

Me too I was at the edge of my seat waiting for the heatsink to be thrown out of a plane.

> No matter how many times ... I keep reading "Heatsink Skydiving".

I always do the same thing with "Homomorphic encryption", I keep reading Homophobic encryption and start wondering what cryptographers have against certain groups of people !

I learned about skiving when I started researching building a watercooled PC. Optimus is building some nice heatsinks/water blocks in Chicago. They’re using a micro CNC process for very fine fins in their cold plates, and mention some of the differences on their site. https://optimuspc.com/products/optimus-gpu-replacement-cold-...

Thanks for this link, I was not aware of this company before and they look like an awesome waterblock company. Good USA based alternative to EK (with less selection obv.)

The other good brand is Heatkiller. Their pump/res combos are really nice, as are their water blocks.

That’s my CPU block currently :) https://flic.kr/p/2mXfr6t

"Choose corrosion-proof electroless nickel finish when using liquid metal" !?

What are people using?

They’re referring to liquid metal thermal compounds, essentially a next-gen replacement for thermal paste that has higher thermal conductivity.

That's fascinating to watch. I am curious why this would be a faster & more robust production process compared to extrusion. I would have guessed it's easier to build it some conventional way.

Thinking about how an extrusion die is made, I imagine it's tricky to make very thin fins and to put them very close together. Copper work-hardens significantly too, which may be a factor.

Copper doesn’t extrude well for small parts for reasons note, as well as it’s overall strength is quite high - yield strength of 20k psi, tensile strength of 32k psi. and it has a pretty high melting and annealing point.

Extruding non-trivially sized parts starts to require some rather extreme equipment quickly, but is done for larger bulk electrical components, pipes, and tubes.

Aluminum heat sinks are extruded regularly. Aluminum tends to be used where heat sinking requirements are less severe, as it has less ideal thermal properties. A lot cheaper though.

If someone is paying the premium for copper, they probably want maximum thermal performance - which also means maximum surface area hence more and thinner fins (as long as the material is thermally conductive enough to keep them ‘fed’ with heat anyway).

Edit: update details.

One advantage is that the blade does not need to be linear. This allows for the creation of patterned fins which my have more ideal properties.

https://www.youtube.com/watch?v=ghrjJ1OL6jM

To skive: avoid work or a duty by staying away or leaving early I wonder how it came to be called skiving?

EDIT: apparently it's origin is french word esquiver which means to slink away

Interesting. I wondered if it was related to the Norwegian/Danish "skive" [1], which means to cut or a cut of something.

[1] which could even be inflected like "skiving", though realistically it might not ever have

edit: of course, it might be that "skive" and "esquiver" are related...

I had not seen a video before, but you can work out this production technique by close inspection of a heatsink. The fins are clearly bent up and have a root that is thicker on one side.

Given the audience, the numbers may be skewed, but how many people really look at a heatsink like that? Aren't most people just too damn excited to get the new system up and running, and just install as quickly as possible after unboxing?

But now that you've mentioned it, I've stared at heatsinks a lot without once considering how it was actually made.

Unrelated, but I used to get a fries with salad on top at Uni on the way home from my part time job and I was so happy to have like 10 series of "How it's Made" as I munched.

I am not talking about Skiving heatsinks specifically, but clearly this is a needed tool, so how did it come to be? What is the job title?

Someone in this case, needed heatsinks quick, so how did it go from someone needing lots of heatsinks to an industrial tool?

Was there a guy shaving copper manually, and some (job title) came to the factory and suggested creating a moving table with a blade to optimise the creation?

Not in metal manufacturing, but semi-knowledgeable with some professional interest.

Metal is machined by cutting tools. The two machine tools that I'd guess are most closely related to this are the shaper (which is totally unrelated to a wood shaper or the confusingly named Shaper Origin) and planer (which is almost completely unrelated to the wood planer, except in rough concept).

Both work by dragging a cutting tool against a workpiece and removing a chip. Both are reciprocal and step over between strokes to cover a wider workpiece surface than the width of the cutting tool. You'd be very unlikely to see either taking a chip this wide in, say, steel because you'd need an immense amount of power and rigidity in the machine to control the cut.

I don't think either typically does any movement in the z axis through their working stroke, and I don't think the stroke typically changes it's starting point along the axis of the stroke.

Nonetheless, the very basic motion and chip formation is close enough that one might reasonably come up with the skiving motion from either of them if it didn't already exist.

Skiving, incidentally is also a term in leatherworking where, as I understand it, it's an operation that reduces the thickness of a piece of leather by slicing action.

I don't know if tapering the end of a leather piece is also known as skiving, or if there's a more specific term for making a slicing cut through the thickness at an angle.

Stop. Moving. THE CAMERA!

I like the part where the camera zooms in but isn't pointed at the spot where things are happening and then slowly pans until it's in frame.

Honestly, looking at the video again, I'm sort of curious as to what exactly is going on with the camera; it seems handheld, but it's also moving in sync with the piece of equipment with the wedge/blade on it. Are they standing on a platform that's fixed to the other equipment?

I think the heatsink and platform it is on are moving horizontally and the blade only moves vertically.

For those who do not immediately see what is going on:

All those heatsink fins you see were just cut and stood up. Each stroke cuts and stands up another one.

Is this the origin of the term to skive off school? I don’t really see the connection.

I thought skiving was only a Scottish term - is it commonly used where you are too?

Growing up in Australia, yes, though unknown in the USA where I am at the moment,

The term appears in at least one of the Harry Potter books (the "Skiving Snackbox" of the Weasley twins contains a range of sweets that make you mildly ill as an excuse to skip class).

Apparently not -- https://www.etymonline.com/word/skive

Interesting etymology though, I love when you see a random PIE root show up in so many languages.

Fabulous! That is a perfect production process. Thanks for sharing.

How you know it is 2022: there is a YouTube channel dedicated to heatsink skiving.

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