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Hackaday Links: June 30, 2019

In our continuing series of, ‘point and laugh at this guy’, I present a Kickstarter for the, “World’s First Patented Unhackable Computer Ever”.  It’s also a real web site and there’s even a patent (US 10,061,923, not showing up on Google Patents for some reason), and a real product: you can get an unhackable laptop, and you can get it in either space gray or gold finish. This gets fun when you actually dig into the patent; it appears this guy invented protected memory, with one section of memory dedicated to the OS, and another dedicated to the browser. This is a valid, live patent, by the way.

The 2019 New York Maker Faire is off. Yeah, it says it’s still going to happen on the website, but trust me, it’s off, and you can call the New York Hall of Science to confirm that for yourself. Maker Media died recently, and there will be no more ‘Flagship’ Maker Faires. That doesn’t mean the ‘mini’ and ‘featured’ Maker Faires are dead, though: the ‘Maker Faire’ trademark is simply licensed out to those organizers. In the next few weeks, there is going to be a (mini) Maker Faire in Coeur d’Alene, Idaho, Gilroy, California, Edmonton, Alberta, Kingsport Tennessee, and a big ‘ol one in Detroit. This raises an interesting question: where is the money for the licensing going? I’m sure some Mini Maker Faire organizers are reading this; have your checks been cashed? What is the communication with Maker Media like?

Just because you can, doesn’t mean you should. It’s valuable words of wisdom like that and can apply to many things. Commenting on blog posts, for example. Yes, you can throw sticks at a wasp’s nest, that doesn’t mean you should. Yes, you can 3D print Heely adapters for your shoes, but it doesn’t mean you should. It does look dope, though and you’re automatically a thousand times cooler than everyone else.

The C64 Mini is a pocket-sized Linux device with an HDMI port meant to play C64 games.   There were high hopes when the C64 Mini was announced, but it turned out the keyboard isn’t actually a mini keyboard. Now someone had the good sense to combine one of these ‘smartphone chips running an emulator in a retro case’ products with a full-sized keyboard. The C64 will be around by Christmas, and yeah, it has a full working keyboard.

Custom Machined Pump Keeps CNC Lubrication Under Control

Rub two pieces of metal against each other hard enough, and it won’t be long before they heat up sufficiently to cause problems. That’s especially true when one is a workpiece and one is a tool edge, and the problems that arise from failing to manage the heat produced by friction can cost you dearly.

The traditional way of dealing with this is by pumping heavy streams of liquid coolant at the workpiece, but while that works, it creates problems of its own. That’s where minimum quantity lubrication comes in. MQL uses a fine mist of lubricant atomized in a stream of compressed air, which saves on lube and keeps swarf cleaner for easier recycling. The gear needed for MQL can be pricey though, so [brockard] decided to add homebrew MQL to his CNC router, with great results.

The video below shows the whole process, from raw metal to finished system – skip ahead to about 12 minutes if you just want to see final testing, but be warned that you’ll be missing some high-quality machining. The finished pump is a double-piston design, with each side driven by a cam rotated by a servo. An Arduino controls the speed of the motor based on the current settings; the pump is turned on and off through G-code control of a relay.

The lubricant stream is barely visible in the video, as opposed to the sloshing mess of traditional flood coolants, and seems much more suitable for a hobbyist-grade CNC setup. Need to build a CNC router before you build this? You can do much worse than this one.

Continue reading “Custom Machined Pump Keeps CNC Lubrication Under Control”

Does The Cheese Grater Do A Great Grate Of Cheese?

Apple’s newest Mac Pro with its distinctive machined grille continues to excite interest, but until now there has been one question on the lips of nobody. It’s acquired the moniker “Cheese grater”, but can it grate cheese? [Winston Moy] set out to test its effectiveness in the kitchen with a piece of Pecorino Romano, a great cheese.

Of course, the video is not really about cheese grating, but about the machining process to create that distinctive pattern of intersecting spherical holes. He doesn’t have a real Mac Pro because nobody does as yet, so like others his approach was to reverse engineer the manufacturing process. He takes us through the entire thing and the rationale behind his decisions as he makes a 13-hole piece of Mac Pro-like grill from a billet of aluminium. It’s first roughly cut with a pair of decreasing-size end mills, then finished with a ball mill. He’s added an extra cut to round off the sharp edge of the hole that isn’t there on the Mac.

An unexpected problem came when he machined the bottom and the holes began to intersect, it was clear that they were doing so wrongly. Turning the piece over must be done in the correct orientation, one to note for any other would-be cheese-grater manufacturers. Finally the piece is blasted for a satin finish, and then anodised for scratch-resistance.

So, the important question must be answered: does it grate? The answer’s no, the best it can manage is something close to a crumble. He doesn’t seem bothered though, we get the impression he likes eating cheese whatever its form. The whole process is in the video below the break.

For more Apple grille examination, take a look at this mathematical analysis.

Continue reading “Does The Cheese Grater Do A Great Grate Of Cheese?”

The Process Behind Manufacturing That Mac Pro Grille

Apple released a monitor stand not so long ago with an eye-watering price tag, and in the resulting fuss you might almost be forgiven for missing the news that they also released a new computer. The distinctive grille on the new Mac Pro caused some interest among Hackaday editors, with speculation rife as to how it had been machined. It seems we’re not alone in this, because [J. Peterson] sent us a link to his own detailed analysis.

The key to the pattern lies in hemispherical holes milled part-way-through a piece of metal on a triangular tessellation, and intersecting with an identical set of holes milled at an offset from the other side. The analysis was done purely from online information as he doesn’t have a real Mac Pro, but using some clever trigonometry he is able to calculate the required offset as well as the hole depth. There are some STL files on Thingiverse, for the curious.

Should you wish to make your own copy of a Mac Pro grille you should therefore be able to use this information in programming a CNC mill to carve it from a piece of alloy plate. The interesting side of it from a manufacturing perspective though is that this is a complex shape that would be difficult to produce in numbers without either CNC or a very specialist one-off machine tool for this single purpose, and neither is a normal expenditure for a mere grille. Perhaps you might come close by rolling alloy plate between rollers whose profile matched the hole pattern, but in that event you would not equal the finish that they have achieved. Apple’s choice to use a relatively time-intensive CNC process in mass-production of a cosmetic part is probably in a large part a quality statement for their particular brand of consumer, but also sets a high bar to any would-be imitators. We applaud it for its engineering, even if we won’t be shelling out for that monitor stand.

Self-Cleaning Camera Lens Makes For Speckle-Free Video

People making videos about machining have a problem: the coolant gets everywhere. When you take a video to show the process of creating a device, the milky gunk that keeps everything cool gets all over your camera lens. AvE is experimenting with an interesting fix for this problem, with a self-cleaning camera lens. (Video embedded below, some salty language.) His prototype uses a spinning piece of clear PVC mounted on BB gun pellets, driven by compressed air. The camera can see through this spinning piece, but when the coolant hits the spinning piece, it is thrown off.

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CNCing An X-Acto Knife Holder

X-acto knives are popular as the scalpel of the craft world. Obviously, holders for the blades are available off-the-shelf, but you needn’t settle for store bought. [Ariel Yahni] set about making an X-acto handle of their own, and it shows just how quick and easy making your own tools can be.

The blades are first measured to determine the appropriate dimensions for the holder. With this done, the basic shape of the handle is drawn up in CAD software using simple primitive shapes and lines. Then it’s just a simple matter of jigging up a piece of aluminium stock in the CNC machine, and letting it do its thing.

The final result needs minimal finishing – primarily just an inspection of the parts, minor deburring and the drilling and tapping of the mount holes. With a couple of socket head cap screws and an X-acto blade installed, it’s ready for work.

We see a lot of interesting tool builds around these parts. You might consider making your own ultrasonic cutter if you’re regularly finishing 3D printed parts. Video after the break. Continue reading “CNCing An X-Acto Knife Holder”

Design Tips For Easier CNC Milling

CNC machining is a wonderful thing, taking away a lot of the manual work required in machining and replacing it with accurate, repeatable computer control. However, this doesn’t mean that you can simply click a few buttons and become a great machinist overnight. There are a wide variety of skills involved in utilizing these tools effectively, and [Adam Bender] has created a guide to help budding makers learn the skills of design for CNC milling. 

[Adam]’s guide starts from a basic level, considering 3-axis CNC milling with the most commonly used tools. From there, a whole range of tips, tricks, and potential pitfalls are discussed to help new machinists get to grips with CNC milling. Everything from dogbone corners, to tool selection and feature heights are covered, as well as cost-saving techniques like minimising the number of setups required.

These are skills any engineer will learn in a hurry when approaching an experienced CNC machinist, but it’s always better to go in forewarned and forearmed. Of course, for those eager to not just work with, but build their own CNC machine, we’ve covered that base too. Video after the break.

Continue reading “Design Tips For Easier CNC Milling”