You Can Build Your Own Sushi Train

March 11, 2022 by Lewin Day 19 Comments

According to [Garage Avenger], in Norwegian culture it’s considered impolite to ask for things to be passed across a dinner table, so much standing and reaching is the course of the day. To assist in reducing the effort required, he set about building his own sushi train device to solve the problem, giving equal condiment access to all!

The system is capable of taking plenty of weight from heavy dinner bowls, altogether quite different than relatively-light sushi dishes on plastic plates.

The system is actually relatively simple, relying on a Wemos D1 Mini controlled by a Blynk app to run the show. Mechanically, a large drive gears is turned by a stepper motor to drive the wooden conveyor chain that actually makes up the “sushi train.” The chain links ride on a bed of Norwegian one krone coins acting as rollers.

The result is a working table-sized sushi train that really does carry plates around well. It didn’t stop people leaning over [Garage Avenger] at the dinner table, but it makes a great centerpiece on the dinner table for sharing dishes like tacos.

We’ve seen similar table technology, the Lazy Susan, around these parts before. Video after the break.
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Very Fancy Nail Is Actually A Secret Jewlery Stash

March 10, 2022 by Lewin Day 10 Comments

Typically, nails are purpose-built things made to hold bits of wood together, with their entire design focused on that purpose. However, [W&M Levsha] went in much the other direction, crafting one very fancy expensive nail in what we can only explain as a masterful demonstration of their skills.

The build starts with a piece of brass tube, which is engraved with a delicate pattern on an automated lathe. After clean up, the spiralling lines are attractive on the polished brass.A plug is then made for the end of the tube, which gets filed into a point to resemble a nail, hiding the seam between the plug and the tube.

The tube is then threaded to accept a nail head that screws into the top, allowing the “nail” to act as a fancy little stash, which [W&M Levsha] shows off by placing a bracelet inside. The project is finished by crafting a stunning wooden box to hold the fancy nail.

We’ve seen [W&M Levsha]’s handywork before; the cap-gun cigarette lighter was a similarly impressive feat of machining and craftsmanship. Video after the break.

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Building A Pendulum Clock Out Of Lego

March 9, 2022 by Lewin Day 10 Comments

Pendulum clocks aren’t used quite as often these days as their cumbersome mechanics and timekeeping abilities have long been outshone by electronic alternatives. However, they’re still fun and they do work, so [PuzzLEGO] set about building a working example with Lego.

The rear view reveals the escapement built from Lego Technic parts.

The core of the clock is the escapement, a linkage which the pendulum can only turn in one direction. As the pendulum swings once per second, it lets the escapement gear turn one notch forward at a time, turning the gears of the clock which drive the hands. It’s powered with a falling weight in the form of a drink bottle full of water, which turns the gears of the clock via a chain.

The clock can only run for approximately an hour, so it’s set up with a second and minute hand instead of the more usual minute and hour hand. However, with the pendulum tuned to the appropriate length and the weight fitted, it pleasantly ticks and tocks the seconds away.

We’ve seen other great builds from [PuzzLEGO] before, too, like this inventive Rubik’s Cube build. Video after the break.

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G4 IMac Gets An M1 Heart Transplant

March 8, 2022 by Lewin Day 7 Comments

The second-generation iMac was a big departure from the original brightly-colored release. The chunky CRT aesthetic was dead, replaced with a sleek design featuring a slim LCD monitor on a floating arm. [Connor55] recently laid his hands on such a machine, and decided it needed a transplant of some modern M1 hardware.

The machine, as it came into his possession, lacked WiFi, and had a disc drive struggling to open its own tray, so it made a good candidate for hacking. Out came the original motherboard and drives, leaving room for a motherboard from a Mac Mini to be substituted in, with the powerful new M1 system-on-chip onboard.

First up, the screen had to be converted to use DVI input, with a guide from [Dremel Junkie] helping out with that. The Mac Mini motherboard was then prepped to install in the iMac’s dome-shaped housing; notably, the entire board is smaller than the stock iMac G4’s hard drive. It still took plenty of cramming, with a multitude of adapters finagled and massaged to fit inside the original housing.

It’s a very completionist build; even features like the original power button and optical drive still work. It took some fiddling, but the display and backlight operate properly as per the original functionality, too.

Apple’s tasteful industrial design has always proved popular with modders. We’ve seen similar builds before over the years, from Intel NUCs stuffed into G4 iMacs to classic Macs outfitted with iPad hardware. It’s always satisfying to see vintage hardware given a new lease of life with modern grunt!

USB Temperature Logger With Some Extra Tricks

March 7, 2022 by Dave Rowntree 5 Comments

Many of us electronics hacker types tend to have at least the same common equipment on our benches, namely a multimeter, an oscilloscope, some sort of adjustable power supply, and maybe a logic analyzer. These are great tools covering many bases, but dealing with temperature measurements is often neglected. A sudden need for such often results in just buying a either dedicated measurement unit, or some cheap eBay thermocouple board and just rolling with a few hacks. [Jana Marie Hemsing] had a need for measuring the thermal side of things, and got fed up with hacking with piles of boards, and designed herself a proper instrument for the task.

The result is a very tidy four-channel thermocouple frontend, feeding the data into the host computer via USB. Each of the four channels can either be a K-type input or a NTC thermistor input, decided at board assembly time, but you could just build two units with four channels of each and cover all bases. The K-type thermocouple input is based around the MAX31855 series device. While the ‘KASA’ suffixed device is probably most common, if you need to dedicate some channels to handling one of the other six or so other common thermocouple types, that just needs the appropriate MAX31855 variant dropping in, and you’re good to go.

For the controller, [Jana] has chosen the common STM32F0x microcontroller, which handles all the USB protocol side of things. The extra functionality added allows direct driving of a heater controller via the DRV8837 H-Bridge, with a extra few open collector outputs for other things you might want to drive. This allows the logger to function as a kind-of thermal IO device. Firmware is written in good old fashioned STM32 HAL, using the standard STM32CubeMX and the GCC toolchain. It looks like the Makefile came via the STM32 Project Generator route. The firmware has a neat trick up its sleeve too; with a flick of the switch on the back, the firmware can switch between outputting CSV data over a standard USB CDC link (a virtual serial port), or it can present a SCPI terminal interface, enabling integration into existing SCPI-based test flows. Nice work!

We’ve seen a few logging projects on these fair pages, like this battery powered ESP32 logger device. If IoT logging is more your thing, here you go.

Pop Goes The Mechanical Ping Pong Sculpture

March 7, 2022 by Matthew Carlson 12 Comments

In the waiting rooms of some dentists or doctors, you might have seen a giant metal ball rolling around in a large glass case. While it sure beats looking through those magazines, the sculpture can’t have come cheap. But not all of us want to pay high-end prices for fun toys. As a more cost-effective alternative, [JBV Creative] built an awesome 3D-printed ping pong sculpture.

The basic concept is the same as those fancy sculptures: a ball goes up, moves through some sort of impressive range of motion as it makes its way back down, and some sort of drive mechanism pushes it back to repeat the cycle anew. The design of this particular art piece is no different. A ping-pong ball falls down a funnel into a queue where balls are slowly loaded via a 12-way Geneva mechanism. An Archimedes spiral cam charges an elastic band that yeets the ball up and out of the track and sends it sailing through the air and down inside the funnel mentioned earlier. Everything on this sculpture is 3D-printed aside from the rubber bands and the ping pong balls.

What’s tricky about these sorts of things is the precision required both in printing and in design. It needs to run for hundreds if not thousands of hours and make no mistake. Making something work correctly 99% of the time is hard, but that last 1% can be almost as much work as that first 99%. [JBV Creative]’s first attempt had a catapult mechanism and he printed and tried out several scoops, but none gave the trajectory that he was looking for.

[JBV Creative] tried a plunger mechanism, but without a counterbalance weight providing the power, it just didn’t have enough oomph to launch the ball. Luckily, holes were included in the design, so it was relatively easy to adapt what had already been printed to use rubber bands instead. An additional goal was to have no visible fasteners, so everything needed to be mounted from the back. Check it out in action after the break.

It’s an incredible project that took serious thought, dedication, and in [JBV Creative]’s words, plenty of CAD twirling. It’s a great lesson in iterating and experimentation. If your talents are more soldering-based rather than CAD-based, perhaps a circuit sculpture is more up your alley?

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DIY Injection Molder Built From A Cheap Pneumatic Press

March 6, 2022 by Dave Rowntree 10 Comments

[Kurt Schaefer] was watching YouTube videos of people making molds for injection molding purposes using what he considered to be the toy 3018 CNC machines, and looking at the results, decided he needed a piece of the action. However, once you have molds, the next obvious issue to address is lack of access to an injection molding machine. But these things are expensive. As luck would have it, you can get a nice-looking pneumatic press for less than $350, and with a little more money spent, [Kurt] found he could convert it into a functional injection molding machine (video, embedded below), and get some half-decent results out of it.

After ordering the press on eBay, what eventually arrived was quite a mess, having clearly been inadequately packed for its weight, and had sustained some damage in transit. Despite this, it seemed the functional bits were fine, so [Kurt] decided to press on with the build. The first obvious change is the requirement of a heated chamber to deal with the feedstock material. Using an off-the-shelf injection molding chamber by buster beagle 3D, only a few standoffs and a support bracket needed machining in order to complete the mechanics. A common PID controller available from the usual suppliers, with some heat bands wrapped around the chamber, dealt with the injection temperature requirements, and some 3D printed enclosures wrapped it all up neatly.

After some initial wobbles, and a couple of hacks to the design, [Kurt] got some pretty good results out of this simple setup, and it appears to be pretty tune-able and repeatable, which will help maintain the quality of those results. In short, a neat hack of easy to get parts, and perhaps a welcome addition to a hackerspace near you?

3D printed parts are available on the Thingiverse page, as well as a Fusion360 CAD model. The shopping list for parts can be found in the video description, if you want to have a go at reproducing this.

We’ve seen a few DIY injection molding attempts over the years, like this slick plastic molding setup. Here’s one with 3D-printed molds, and if you just need something the right shape, you could just injection mold with a hot glue.

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