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How to Make Apple’s Mac Pro Holes (saccade.com)
207 points by ProZsolt 6 months ago | hide | past | web | favorite | 86 comments

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

For the woodworkers, here’s a guy making a low tech version out of cherry...


I wonder if there's a good way to make spherical holes w/ the standard woodworker tools. Unfortunately he only did cylindrical holes.

Sure, you can get ball-end router bits[1]. It would be a pain in the ass to replicate this design without splitting the stock down the middle, though.

1. https://www.toolstoday.com/router-bits/ball-end-router-bits....

There's drill bits that do that

Except those are cylindrical holes, not spherical ones.

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?

This is an extremely expensive, low volume product. I would not be surprised if manufacturing uses the same process as prototyping.

I bought one in ~2014 - when I picked it up at the Apple store, the representative told me it was the first time he'd ever seen someone buy one (apparently he'd worked there for several years).

I exclusively use Linux distros on it now - hopefully they make it easy to do that on the new machines.

While I don’t doubt that the MacPro was a low volume machine, I doubt that most people buying one were buying it from a physical Apple Store where customization was limited.

It's impossible to install Linux to the preinstalled SSD on any recent Mac, though on this one you can at least add your own additional storage and it probably won't be too hard to get Linux booting off that. Aside from the SSD the hardware seems to be pretty normal stuff that already has Linux drivers.

Though I don't see why anyone would want to pay the rather large price premium of this machine if they're not running MacOS on it.

Looks more like a fun weekend project[1] than an impossible task. At least for my mid 2017 MBP. I’ve always had issues with WiFi cards doing a hackintoshes or Linux on macs.


The T2 chip that makes installing Linux to the internal SSD impossible was introduced in the 2018 models.

May I ask why do you buy Mac of you're working exclusively on Linux?

It was for work at the time, they had iPhone apps in their portfolio

You could do this a variety of ways. Ball mill would work fine.

If you were doing this in "real" volume, you would likely likely just cast aluminum into this shape.

However, companies like apple/amazon/etc have a tendency to just find a supplier who can sell them semi-specialized machines and buy a lot of them.

Apple has bought out (either the machines or capacity) for things like laser drilling.

Amazon echo/echo show's were made by buying a ton of semi-custom machines from these folks: https://mdaprecision.com/

(They talk about it in various places)

You'd want a ball mill. Keeping it in good condition and sharp might be an issue, though. (Although not nearly as big a problem if the case is aluminium.

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

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.

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.

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:


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!

The stock material is aluminium alloy, it’s not that hard on tooling.

"milling is different than drilling in this respect"

Is it?

With drilling you need to evacuate material also.

Or am I misunderstanding something, I am far from an expert in such things.

With drilling, the fluted drill bit evacuates material for you. When milling, you don't have the same luxury.

Could you perhaps have an end mill with catch-holes on the insides between the teeth(?), leading to a central hollow in the end mill, on which a vacuum is pulled to pull the material through and out, allowing the end mill to just bore continuously? (Sort of a very tiny solid-state version of a tunnel-boring machine, if you can picture that.)

That’s not feasible for a few reasons. The size difference between a cutting tool and the chip it produces is much smaller than the difference between a digging machine and rocks/gravel. The relative strength is also an issue, strings of steel or aluminum aren’t going to be sucked into a hole as readily as loose material. Lastly the geometry of a cutting head would be tricky if you need the chip to go towards the center instead of being thrown out. I guess it could work if you were milling something that turns into a fine material, like graphite. (Now THAT was a messy day in the shop)

I can see the problem with wide chip, yeah.

Specifically re: strings, though, I’ve always wondered whether—as a separate problem—it’d be possible to have an end mill or drill that dices long stringy chip into shards. Seems like it’d make operation/maintenance easier in some respects. Maybe a bit with two parts, where the tip (either end mill or drill) has counter rotation against teeth running down the rest of the bit, such that the chip gets sheared as it encounters the interface between the two parts?

Also not an expert here, but doesn't an end mill have flutes too?

It does, but the ability to evacuate material straight out of a hole is very limited. Some are designed for side milling only, others can do plunge cuts but it's mainly done to expose a new "shelf" so that the bulk of the material removal can be done using the side of the tool.

Right ok, thanks :)

Ball end mill.

This is now one of my favorite videos :)

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.

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.

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).

Inspecting a finished product should answer this question?

A waterjet/laser makes plenty of sense if you're interpolating anyway. And ball Mills aren't designed for plunge cutting, so using two different tools would be a suboptimal solution. Since the holes have no features in the z dimension, there's just no reason to use one in this particular case.

Edit: ok, looks like it is hemispherical, so you're right. I had thought initially that it was two layers of offset circular holes.

Or you can load the CAD setup in something like SolidWorks and it will generate for you the required toolpath for a specific machine.

That’s what they said. The tool path here isn’t the hard part and if you used anything other than a ball end mill you’d waste a ton of time and come out with a worse result.

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. 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?

They found a company that built machines that could laser mill 20um holes and bought them out. It's unclear if they bought the capacity (i.e. all their stock) or if they actually acquired them. The reports vary.


They’ve done both right? Gorilla glass was a capacity pickup?

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


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...

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

Cool, I figured someone must have reported on it, but couldn't find that.

They mill it from the back until it's quite thin and then blast some holes through with a laser.

Yes, they use lasers. The old MacBooks used to have the webcam light in screen bezel use this tech. It seems to be slowly disappearing (has disappeared?) from their products though.


"What happened when Apple wanted to CNC machine a million MacBook bodies a year? They bought 10k CNC machines to do it. How about when they wanted to laser drill holes in MacBook Pros for the sleep light but only one company made a machine that could drill those 20 µm holes in aluminum? It bought the company that made the machines and took all the inventory" [1] (2014)

[1] https://blog.bolt.io/no-you-cant-manufacture-that-like-apple...

It's an either super thinly machined or super finely laser perforated area (or both).

They used to do this on MacBook Pros as well, I'm not sure whether they still do it.

I would guess Electric Discharge Machining.

That photo is so dark and blurry that I can't see the holes.

Sorry, it was served as full resolution and quality on desktop for me, but significantly worse on mobile. Should have uploaded a closer crop I guess. Try "request desktop version" if your browser can do that.

It's as bright as it can be while still picking up the LED light.

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.

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

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

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

Word from the people who saw it first-hand at Apple's WWDC is that it is not a problem when you're looking at the machine AFK, because your vision has a depth sense, but video and images look very weird.

When I first saw the ads I thought it was two flat pieces of metal with circles cut in each. It took a lot of photographs for me to understand the actual shape. So I can see a shift in perspective making a big difference in perception.

Same! I didn't realize it wasn't just circles cut on two sheets of metal until I saw this video on their design page: https://www.apple.com/105/media/us/mac-pro/2019/36178e80-30f...

I never had that problem until I read an article about that being a problem people had. And then I spent several years being very weirded out by evenly spaced holes in things. And then I got mostly over it. And now your comment has my skin tingling again at the thought....

Same here. The front of the Mac Pro and the back of the XDR display physically nauseates me.

I wonder if you can find an appropriately sized speaker cover to snap onto the front of it...

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.

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.

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.

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.

Interesting theory. A similar mental problem is a plot element in the sci-fi novela "Blindsight" by Peter Watts: https://www.rifters.com/real/Blindsight.htm

Think of it like the (much more common) disgust reaction to the smell of rotten organic matter. Most people have not actually had the experience of eating something putrid and getting sick from it, but something deep within your sensory system just knows, and tells you it's not ok. It's not debilitating. You can still pick up your dog's poop, or even hold a job in the sanitation industry. It's just really unpleasant.

FWIW I had my first really strong trypophobia reaction to the shattered glass on my family minivan's windshield after hitting a deer, age 7 or so, long before Reddit. (No injuries, other than the deer, just inconvenience). I felt weird. I kept thinking about it afterward. I wanted to bash it in. Discovered more than 10 years later that there's a name for it and and it's a thing other people experience.

I recommend googling things you don't understand instead of trying to shut down opinions.

I too think it's a reddit-ism. Same with thalassohobia. Cool sub though with awesome pics.

Have you made efforts to overcome the phobia?

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.

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.

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?

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

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

They claim it is ”a lightweight lattice pattern that maximizes airflow while creating an extremely rigid structure.“

They also claim maximum continuous power is 1280W at 108–125V or 220–240V/1180W at 100–107V, so I can imagine getting enough airflow without building a hoover (I don’t expect this thing to be silent, but they will hav tried hard to make it as silent as possible) was a bit of a challenge.

Looks only. It is far from an optimal shape for airflow or thermal transfer

What concerns me is that I haven't seen any sort of dust filter on this box with high volume fans. That seems to be a recipe for rapidly dust-coated components.

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.

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

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

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.

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.

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

"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.

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