Spring-Loaded Bed For K40 Laser Acts As An Auto-Focus

December 2, 2018 by 12 Comments

Laser engraving and cutting has something in common with focusing the sun’s rays with a magnifying glass: good focus is critical to results. If materials of varying thicknesses are used, focus needs to be re-set every time the material changes, and manual focusing quickly becomes a chore. [Scorch Works] has a clever solution to avoid constant re-focusing that doesn’t involve sensors or motors of any sort. The result is a self-adjusting bed that compensates for material height changes, ensuring that the top surface of the material is always a fixed distance from the laser’s head.

The way [Scorch Works] has done this is to make two spring-loaded clamps from angle aluminum and a few pieces of hardware. When a sheet of material is placed into the machine, the edges get tucked underneath the aluminum “lips” while being pushed upward from beneath. By fixing the height of the top layer of angle aluminum, any sheet stock always ends up the same distance from the laser head regardless of the material’s thickness.

[Scorch Works] shows the assembly in action in the video embedded below, along with a few different ways to accommodate different materials and special cases, so be sure to check it out.

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Wheel Of Fortune Gets Infinite Puzzles On NES

December 2, 2018 by 20 Comments

Wheel of Fortune is a television game show, born in the distant year of 1975. Like many popular television properties of the era, it spawned a series of videogames on various platforms. Like many a hacker, [Chris] had been loading up the retro NES title on his Raspberry Pi when he realized that, due to the limitations of the cartridge format, he was playing the same puzzles over and over again. There was nothing for it, but to load a hex editor and get to work.

[Chris’s] initial investigation involved loading up the ROM in a hex editor and simply searching for ASCII strings of common puzzles in the game. Initial results were positive, turning up several scraps of plaintext. Eventually, it became apparent that the puzzles were stored in ASCII, but with certain most-significant-bits changed in order to mark the line breaks and ends of puzzles. [Chris] termed the format wheelscii, and developed an encoder that could turn new puzzles into the same format.

After some preliminary experimentation involving corrupting the puzzles and testing various edge cases, [Chris] decided to implement a complete fix. Puzzles were sourced from the Wheel of Fortune Puzzle Compendium, which should have plenty of fresh content for all but the most addicted viewers. A script was then created that would stuff 1000 fresh puzzles into the ROM at load time to minimize the chances of seeing duplicate puzzles.

ROM hacks are always fun, and this is a particularly good example of how simple tools can be used to make entertaining modifications to 30-year-old software. For another take, check out this hack that lets the Mario Bros. play together.

CNC Machine Most Satisfyingly Mills Double-Sided PCBs

December 2, 2018 by 50 Comments

We know that by this point in the development of CNC technology, nothing should amaze us. We’ve seen CNC machines perform feats of precision that shouldn’t be possible, whether it be milling a complex jet engine turbine blade or just squirting out hot plastic. But you’ve just got to watch this PCB milling CNC machine go through its paces!

The machine is from an outfit called WEGSTR, based in the Czech Republic. While it appears to be optimized for PCB milling and drilling, the company also shows it milling metals, wood, plastic, and even glass. The first video below shows the machine milling 0.1 mm traces in FR4; the scale of the operation only becomes apparent when a gigantic toothbrush enters the frame to clear away a little swarf. As if that weren’t enough, the machine then cuts traces on the other side of the board; vias created by filling drilled holes with copper rivets and peening them over with a mandrel and a few light hammer taps connect the two sides.

Prefer your boards with solder resist and silkscreening? Not a problem, at least judging by the second video, which shows a finished board getting coated with UV-cure resist and then having the machine mill away just the resist on the solder pads. We’re not sure how they deal with variations in board thickness or warping, but they sure have it dialed in. Regardless of how they optimized the process, it’s a pleasure to watch.

At about $2,600, these are not cheap machines, but they may make sense for someone needing high-quality boards with rapid turnaround. And who’s to say a DIY machine couldn’t do as good a job? We’ve seen plenty of them before, and covered the pros and cons of etching versus milling too.

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3D Printed Brushed Motor Is Easy To Visualize

December 1, 2018 by 5 Comments

A motor — or a generator — requires some normal magnets and some electromagnets. The usual arrangement is to have a brushed commutator that both powers the electromagnets and switches their polarity as the motor spins. Permanent magnets don’t rotate and attract or repel the electromagnets as they swing by. That can be a little hard to visualize, but if you 3D Print [Miller’s Planet’s] working model — or just watch the video below — you can see how it all works.

We imagine the hardest part of this is winding the large electromagnets. Getting the axle — a nail — centered is hard too, but from the video, it looks like it isn’t that critical. There was a problem with the link to the 3D model files, but it looks like this one works.

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Connect Your Electric Heater To The Internet (Easily And Cheaply)!

December 1, 2018 by 18 Comments

Winter has arrived, and by now most households should have moved on from incandescent bulbs, so we can’t heat ourselves that way. Avoiding the chill led [edent] to invest in an electric blanket. This isn’t any ordinary electric blanket — no, this is one connected to the Internet, powered by Alexa.

This is a project for [edent] and his wife, which complicates matters slightly due to the need for dual heating zones. Yes, dual-zone electric heating blankets exist (as do two electric blankets and sewing machines), but the real problem was finding a blanket that turned on when it was plugged in. Who would have thought a simple resistive heating element could be so complicated?

For the Internet-facing side of this project, [edent] is using a Meross smart plug and a Sonoff S20 smart plug. These are set up through to work with Alexa and configured as an ‘electric blanket’ group. Simply saying, “Alexa, switch on the electric blanket” turns on the bed.

There are a few problems in need of future improvement. Alexa doesn’t recognize voices, so saying ‘Turn on my side of the bed’ doesn’t work. The blanket also shuts off after an hour, but the plug sockets stay live. There’s also the possibility that hackers could break into this Alexa and burn down the house, but this is a device on the Internet; that sort of stuff virtually never happens.

You can check out the demo of the electric bed below.

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Arcade1up Cabinet Mod Raspberry Pi 3

Arcade1up Cabinet Solderless Upgrade With A Side Of Raspberry Pi

December 1, 2018 by 17 Comments

Upon announcement of the Arcade1up replica arcade cabinets earlier this year, many laid in waiting for the day they could see a teardown. A four foot tall cab with an LCD outputting the proper 4:3 aspect ratio and the simple construction of IKEA furniture certainly seemed appealing. In theory, it wouldn’t take long to customize such a piece of hardware provided the internals lent themselves to that sort of thing. Now that the cabinets are on store shelves, [ETA Prime] made a tutorial video on his method for upgrading the Arcade1up cabinet with a Raspberry Pi calling the shots.

The entirety of the mod is solder-free and uses plenty of readily available parts from your favorite online reseller. The brains of the operation is a Raspberry Pi 3 Model B+ running Emulation Station. The Arcade1up Street Fighter 2 cabinet’s less than stellar audio receives an upgrade in a 2x20W car audio amp, while the middling joysticks are swapped out for some more robust Sanwa-clone ball tops.

Since there is no “select/coin” button natively, [ETA Prime] added some and in the process replaced them all with beefier LED-lit 30mm buttons. The replacement joysticks and buttons were all part of a kit, so they plug-in conveniently to a plug and play USB encoder. To adapt the 17″ LCD’s output over LVDS, [ETA Prime] elected to go with an LCD controller board that outputs DVI, VGA, or HDMI. Luckily the Arcade1up cabinet’s 12V power supply could be reused to power the LCD controller board and in the process bring down the overall cost of the upgrade.

While this Arcade1up cabinet mod won’t solve the whole “bats versus ball tops” argument, it does provide a template to build on. The tutorial video is below and the list of parts used can be found in the YouTube description.

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Naomi Wu On The Sino:Bit, 3D Printers, And Open Source Hardware In China

December 1, 2018 by 8 Comments

Many readers will be familiar with [Naomi Wu], the prolific hardware hacker who has shown us so much of the epicentre of Chinese tech in her native Shenzhen through a lens that most outsiders would struggle to achieve. We’ve seen her touring factories and electronics marts, building a load of interesting projects, and achieving the first open source hardware certifications in China.

We’ve seen a lot of [Naomi] speaking to us in English as an audience outside her country, so it is extremely interesting to see her latest video posting in which she makes her case for open source hardware in Chinese to a Chinese audience (Chinese audio with English subtitles). She’s speaking at the recent China open source conference, and her description starts with “**THIS IS VERY BORING UNLESS YOU ARE INTO OPEN SOURCE**”, which we think is a little unfair as it should appeal to anyone with an interest in the Chinese tech business.

In the talk she takes us through the potential benefits of open source to Chinese business by using her projects as case studies. In particular she concentrates on how the arguments for open source in a commercial arena have to be made differently for a Chinese business to those used in the rest of the world. Using the analogy of a college dorm hotpot party, she outlines the importance of a community in open-source development, then we get a blow-by blow account of her work with Elecrow and Creality on the Sino:bit (a single-board computer targeting education in China) and the 3D printers.

The software support for the Sino:bit in particular demonstrates the added value of open source to a business, with significant tutorial and curriculum material coming from Adafruit Industries, Hindi language and character set support from developers in India, and a Chinese developer painstakingly transcribing all the Chinese character set for the device. That last step alone would have cost a non open-source developer a significant sum.

During her talk we are shown the commercial benefits to all three devices, for example one of the Creality 3D printers rapidly becoming Amazon’s top seller despite an array of knock-off machines appearing. We’ve embedded the video below the break, and we think it should be required viewing for anyone with an interest in open source or the Chinese tech industry.

Once you have seen the video you might find [Naomi’s] guide to buying on Taobao to be of interest, as well as her explanation of the Chinese cultural attitude to engineers while introducing us to the historical master craftsman, [Lu Ban].

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