
How to Make Apple’s Mac Pro Holes - ProZsolt
http://saccade.com/blog/2019/06/how-to-make-apples-mac-pro-holes/
======
wongarsu
For a more practical take on the same problem here's a youtube video of
somebody machining the holes on a CNC (and testing its performance as a cheese
grater):
[https://www.youtube.com/watch?v=s29YZqe9Cso](https://www.youtube.com/watch?v=s29YZqe9Cso)

~~~
seniorsassycat
Do you think this is the process that Apple's manufacture uses?

Could they use an end mill the same size as the hole, instead of a smaller end
mill that follows a circular path?

Could they have built a machine with many end mills, correctly spaced, to
drill all holes in one shot?

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shawnz
But the holes are spherical, not cylindrical. How could you do that with an
end mill the size of the hole?

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neetdeth
With a ball end mill, theoretically.

Not that it's a good idea - you need to be able to actually evacuate material
from the surface you're cutting, and milling is different than drilling in
this respect. But I imagine you could come up with a very fast two step
program using a cylindrical end mill for plunging/roughing and a relatively
large ball end mill for finishing.

~~~
oflannabhra
My understanding is that using a ball end mill to "drill out" a hemisphere
while perpendicular to your surface will create very high forces that are bad
for the tool. I'd imagine you could offset the tool axis and then achieve the
same effect, but using a smaller tool might end up being easier.

Please note that I am far from even a beginner machinist.

~~~
neetdeth
Right, that's the idea I was trying to express. Don't expect anything good to
happen if you try to plunge a ball end mill straight down into the material.

The thought was only that a large-radius ball would be able to approximate the
sphere to within tolerance with larger stepover than a smaller tool. After
bulk material removal with a more suitable cylindrical tool of course.

With a little bit of googling I discovered a different class of end mill
called a circle segment tool, which could potentially make short work of the
problem in a 5-axis machine:

[https://www.moldmakingtechnology.com/videos/circle-
segment-t...](https://www.moldmakingtechnology.com/videos/circle-segment-
tools-and-toolpaths-in-action)

Would love to see how Apple does it, but it's never happening.

I'm not really a machinist either, but let's not allow that to stop us from
incorrecting each other on HN!

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mdorazio
Thought this would be about the machining setup to make them, not the math of
the CAD setup. To actually machine this, you would basically use a ball end
mill (which has a roughly half-sphere end) and drill a bunch of offset holes
according to the pattern outlined in this writeup.

~~~
defterGoose
A ball-end mill wouldn't be the best tool for this, they're meant more for 3d
contouring. They've probably just used a normal endmill and interpolated each
hole or used an appropriately sized drill. And at the volumes they're
manufacturing, waterjet or laser-cutting (not as good for aluminum) are likely
the method of choice.

~~~
jacobolus
A waterjet / laser cutter makes no sense as a way to cut a hemispherical hole.

It seems highly likely there is a ball end mill involved in getting the final
smooth shape (maybe after roughing out the holes with a cylindrical tool). The
main question is whether the ball is the same size as the hole, or a bit
smaller (which would require it to move around in little spiral paths instead
of just going in and out once).

~~~
londons_explore
Inspecting a finished product should answer this question?

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alanbernstein
On the subject of Apple's hole-machining process, I recently noticed how tiny
the light-grill holes are on the older wireless Apple keyboards:
[https://i.imgur.com/l9n9Cp2.jpg](https://i.imgur.com/l9n9Cp2.jpg). Look at
the ruler, marked in mm - the holes are less than .1mm in diameter. I was
wondering how they did this, I guess a laser or plasma cutter is the only way?

~~~
evv
Lasers. I think their technique is top-secret, because I don't see lights-
through-metal on many other products.

[https://venturebeat.com/2011/11/04/apple-laser-
manufacturing...](https://venturebeat.com/2011/11/04/apple-laser-
manufacturing/)

~~~
amelius
Aren't lasers a standard method for cutting 2d work?

Perhaps they are using the same technique, but in a 3d setup.

Edit: found an interesting link: [https://www.twi-global.com/technical-
knowledge/faqs/faq-what...](https://www.twi-global.com/technical-
knowledge/faqs/faq-what-are-the-problems-with-laser-cutting-of-aluminium-and-
how-do-i-overcome-them)

> The 'aluminium cutting system' which most modern equipment uses is actually
> a way of protecting the laser rather than an innovative technique for
> cutting.

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dbg31415
In 7th grade wood shop in the early 90s I built this design into a wood box we
had to make. I used a drill press with a plunge ball router bit, and set up
the design to start about an inch in after the joins. The design looked great,
box used 3/4 inch plywood, and was about 24” x 14” x 14”. My shop teacher
hated it, said it wasn’t art class that it wouldn’t be as sturdy. Anyway long
story short, when I was about 4 years older someone sat on it and that was
that. So yeah, was cool... wasn’t as sturdy.

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sago
And here's someone following though and making them:
[https://www.youtube.com/watch?v=s29YZqe9Cso](https://www.youtube.com/watch?v=s29YZqe9Cso)

~~~
yawniek
saw this recently, winston moy does very cool videos, make sure to check out
his other projects!

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pibefision
I have trypophobia. Cannot believe this is a new design style.

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cheeze
Circular patterns? Been a design style for the past 10+ years.

Tryophobia sounds like one of those "I have OCD" things because people are "so
peculiar." I'm not discounting that folks may have a legitimate mental illness
resulting from it, but that has to be an overwhelming minority of users.

~~~
userbinator
I wouldn't exactly call it a "mental illness", but upon seeing such images I
can feel my brain heating up in the same way as when I'm thinking of a
difficult problem. My theory is that it's essentially overloading the edge
detection (neural) circuitry, because the one thing that all such images have
in common is they have plenty of circular edges, which are effectively edges
in many directions simultaneously.

~~~
defterGoose
I have fairly pronounced trypophobia too. I was under the impression that the
leading theory is an evolutionary one; that certain burrowing insects will lay
eggs in the skin causing a pattern of holes and that our brains have been
trained to read this and other parasites. Yours is certainly interesting,
though anecdotally I can look at a very regular pattern of holes and not feel
the effect. It only really "bugs" me with more irregular, organic patterns.

~~~
sangnoir
I get a mild disgust/nausea/skin-crawl reaction. I lean towards evolutionary
theory: your lizard brain is telling you "don't touch/eat this parasite-
infested item". The worst trigger for me was an image was a (photoshopped)
picture of skin with holes, and some had maggots in them.

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ksec
Has someone figure out an explanation why these holes makes better air flow as
suggested by Apple? It would have been easier if the metal holes were used
heat sink. But I doubt they are, and those shape should only block airflow,
and not improves it.

~~~
GuB-42
I tired doing a few calculations and by surface area alone, the pattern is
about 55% unobstructed. That's better than the pattern from the original
cheese grater, and given how terrible the trash can was, one hopes they did
better this time.

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syntaxing
I think there's a large concensus that this is made via milling but wouldn't
ram EDM be the best method for a shape like this?

~~~
d-sc
Maybe, but then the EDM tool will get used up. So then you have to figure out
how to machine it.

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elil17
Are there thermal advantages to the design or is it just for looks?

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redorb
I think there is some, but it couldn't be worth the cost. The marketing said
there was 'more air than metal' which I thought was good marketing.

~~~
olliej
Maybe it does help reduce weight? Seriously the old cheese grater was absurd

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m3kw9
One thing that copiers forgetnis to shave the edges so it is not jagged and
slice up your fingers, I will bet the edges one the Mac are shaved

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ginko
The only thing I'm thinking of when seeing the Mac Pro's holes is that they
must be a complete PITA to keep clean of dust.

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Theodores
It is not exactly the radiator grille of a WW2 era Jeep - 9 slots stamped out
of steel.

If you had to build your own computer and you had the choice of more RAM or a
fancy hood ornament, what would you go for? I would be inclined to go for the
former.

But it is not about that. If you go into a post production edit suite where
they do fancy things then the clients have a fancy sofa with a well stocked
fridge. Not a few plastic chairs and a cooler box. People hiring these
services expect a certain amount of wow factor to know they have arrived.

Years ago the tech had a certain amount of power projection to it. If the box
was big and purple with 'Silicon Graphics' written on the front of it then you
knew the toys were the real deal. But, despite the fancy cases to these
machines they were not fancy for the sake of it. They just exuded class, much
like how a European hypercar just says something that a Toyota saloon fails to
achieve despite having four wheels and an engine.

I am not sure that Apple really hit the high notes of wow factor with this
case design for the benefit of the clients. The case speaks more to the users
than the clients. A veritable status symbol, but, then again, when it comes to
bang per buck, it is more hood ornament than engine displacement.

Design is about efficiency of manufacture as well as how it looks. I look at
this and I know that some robot spent a long time drilling the holes. It is
hood ornament. One thing you want with vents is ease of cleaning. The design
statement, if made in plastic as a pop-out panel could be popped out and given
a scrub. In 2-3 years time with a layer of gunk inside how do you get this
cleaned up? It gets a bit fiddly. And all for a hood ornament.

I think that it looks pretty but how do you put the thing in the machine room?
They could have done a 19" rack variant with 'ears' rather than a cheese
grater. Sure it has wheels for under the desk but I would prefer to press the
power button on the front rather than wheel the box out first before getting
to the button.

~~~
esoterica
“Exudes class” is just marketing speak for “fancy for the sake of it”.

~~~
na85
"Fancy for the sake of it" works well when you're a designer and are trying to
land a big contract with shallow marketing people.

