Industrial 3D Printing Uses Layers Like We’ve Never Seen Before

We’ve seen FDM printers lay down layers by extruding plastic in a line. We’ve seen printers use sintering and lithography to melt or cure one layer at a time before more print medium moves into place for the next layer. What we’ve never seen before is a printer like this that builds parts from distinct layers of substrate.

At the International Manufacturing Technology Show last week I spoke with Eric Povitz of Impossible Objects. The company is using a “sheet lamination process” that first prints each layer on carbon fiber or fiberglass, then uses a hydraulic press and an oven to bake the part into existence before bead-blasting the excess substrate away. Check out my interview with Eric and join me below for more pictures and details.

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Better Than Original Pong Using Arduino

Games like Pong are legendary, not only in the sense that they are classic hours fun but also that they have a great potential for makers in stretching their learning legs. In an attempt at recreating the original paddle games like Pong and Tennis etc, [Grant Searle] has gone into the depths of emulating the AY-2-8500 chip using an Arduino.

For the uninitiated, the AY-3-8500 chip was the original game silicon that powered Ball & Paddle that could be played on the domestic television. Running at 2 MHz, it presented a 500 ns pixel width and operated to a maximum of 12 Volts. The equivalent of the AY-3-8500 is the TMS1965NLA manufactured by Texas Instruments for those who would be interested.

[Grant Searle] does a brilliant job of going into the details of the original chip as well as the PAL and NTSC versions of the device. This analysis will come in handy should anyone choose to make a better version. He talks about the intricacies of redrawing the screen for the static elements as well as the ball that bounces around the screen. The author presents details on ball traversal, resolution, 2K memory limit and its workarounds.

Then there are details on the sound and the breadboard version of the prototype that makes the whole write-up worth one’s time. If you don’t fancy the analog paddles and would rather use a wireless modern-day touch, check out Playing Pong with Micro:bits

Thanks [Keith O] for the tip.

Playing Pong With Micro:bits!

Where would the world be today without Pong, perhaps a lot less fun? For people like [Linker3000] the game is an inspiration toward teaching the next generation of hackers to build and play their own version using Micro:bits as controllers!

Aiming for doing all manner of diligence, [Linker3000] says the code can simply be uploaded to an Arduino — foregoing throwing together a circuit of your own — if you want to jump right into things. For the workshop environment, this setup uses composite video outputs — but this shouldn’t be an issue as most TVs still retain these inputs.

Once built — or sketch uploaded — the Micro:bit paddles can be connected to the ATmega328p and played like an old-school controller, but [Linker3000] has enabled Bluetooth control of the paddles’ A and B buttons via the Bitty app. Additionally — if wires really aren’t your thing and Bluetooth is too new-school for such an old game — a second Micro:bit can control the wired paddle using their built-in radio, provided they’re configured accordingly.

On top of Pong, there are also squash and soccer game modes! Check out the demo after the break.

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Xbox Needs No TV

If you want a custom video game system, you could grab a used computer, throw an emulator on it, and build yourself a custom arcade cabinet. On the other hand, if you’d rather not deal with emulators, you can always use a console and modify it into your own tiny arcade cabinet using the original hardware. That’s what the latest project from [Element18592] does, using an Xbox 360 Slim and a small LCD screen to make a mini-arcade of sorts.

The build uses a 7″ TFT LCD and a Flexible Printed Circuit (FPC) extension board. The screen gets 12V power from the Xbox and another set of leads are soldered directly to the composite output on the motherboard. The project also makes use of a special switch which can enable or disable the built-in monitor and allow the Xbox to function with a normal TV or monitor.

Admittedly, he does point out that this project isn’t the most practical to use. But it is still a deceptively simple modification to make to the Xbox compared to some of the more complicated mods we’ve seen before. The fact that almost anyone could accomplish this with little more than some soldering is an impressive feat in the world of console mods.

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Junkyard Crossbow Aims to be a Car Killer

[James], aka [Turbo Conquering Mega Eagle], is not your typical Hackaday poster boy. Most of his builds have a  “Junkyard Wars” vibe, and he’d clearly be a good man to have around in a zombie apocalypse. Especially if the undead start driving tanks around, for which purpose his current anti-tank compound crossbow is apparently being developed.

At its present prototype phase, [James]’ weapon o’ doom looks more fearsome than it actually is. But that’s OK — we’re all about iterative development here. Using leaf springs from a Toyota Hi-Lux truck, this crossbow can store a lot of energy, which is amplified by ludicrously large aluminum cams. [James] put a lot of effort into designing a stock that can deal with these forces, ending up with a composite design of laminated wood and metal. He put a lot of care into the trigger mechanism too, and the receiver sports not only a custom pistol grip cast from aluminum from his fire extinguisher foundry, but a hand-made Picatinny rail for mounting optics. Test shots near the end of the video below give a hint at the power this fully armed and operational crossbow will eventually have. The goal is to disable a running car by penetrating the engine block, and we’re looking forward to that snuff film.

If rubber band-powered crossbows are more your speed, take you pick — fully automatic, 3D-printed, or human-launching.

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Casting Machine Bases in Composite Epoxy

When you’re building a machine that needs to be accurate, you need to give it a nice solid base. A good base can lend strength to the machine to ensure its motions are accurate, as well as aid in damping vibrations that would impede performance. The problem is, it can be difficult to find a material that is both stiff and strong, and also a good damper of vibrations. Steel? Very stiff, very strong, terrible damper. Rubber? Great damper, strength leaves something to be desired. [Adam Bender] wanted to something strong that also damped vibrations, so developed a composite epoxy machine base.

[Adam] first takes us through the theory, referring to a graph of common materials showing loss coefficient plotted against stiffness. Once the theory is understood, [Adam] sets out to create a composite material with the best of both worlds – combining an aluminium base for stiffness and strength, with epoxy composite as a damper. It’s here where [Adam] begins experimenting, mixing the epoxy with sand, gravel, iron oxide and dyes, trying to find a mixture that casts easily with a good surface finish and minimum porosity.

With a mixture chosen, it’s then a matter of assembling the final mould, coating with release agent, and pouring in the mixture. The final result is impressive and a testament to [Adam]’s experimental process.

We’ve seen similar builds before — like this precision CNC built with epoxy granite — but detail in the documentation here is phenomenal.

Soluble Molds For Composite Parts

People have been experimenting with 3D printed molds for fiberglass and carbon fiber for a while now, but these molds really aren’t much different from what you could produce with a normal CNC mill. 3D printing opens up a few more options for what you can build including parts that could never be made on any type of mill. The guys at E3D are experimenting with their new dissolvable filament to create incredible parts in carbon fiber.

For the last year, E3D has been playing around with their new soluble filament, Scaffold. This is the water-soluble support material we’ve all been waiting for: just throw it in a bucket of warm water and it disappears. The normal use case for this filament is as a support material, but for these experiments in composites, E3D are just printing whole objects, covering them in carbon fiber prepreg, vacuum bagging them, and allowing them to cure. Once the carbon fiber isn’t floppy and gooey, the support material is dissolved in water, leaving a perfect composite part.

E3D aren’t that experienced with composites, so they handed a bit of filament off to So3D for some additional experimentation. The most impressive part (in the title pic for this post) is a hollow twisted vase object. This would have required a six-part machined mold and would have cost thousands of dollars to fabricate. Additional experiments of embedding ABS parts inside the Scaffold mold were extremely successful.

As you would expect, there are limitations to this process. Since E3D are using a dissolvable mold, this is a one-time deal; you’re not going to be pulling multiple composite parts off a 3D printed mold like you would with a machined mold. Curing the parts in a very hot oven doesn’t work — Scaffold filament starts to sag around 60°C. Using prepreg is recommended over dry fabric and resin, but that seems to be due more to the skill of the person doing the layup rather than an issue with materials.