[Jon] achieves this by re-creating the trains’ motion using LED strips. A total of 3000 LEDs are spread along more than nine meters of track and make a mesmerizing light show of several trains whizzing along the track, accelerating and slowing down exactly like the real thing.
In his video, [Jon] explains the process of generating an accurate 3D model of the track starting from nothing more than an overhead view of the park as well as photos taken from various angles. The surrounding terrain and buildings are also included in his 3D model, as are the 128 supports that hold the track in place. The terrain and building were made from plywood and foam using a CNC machine, while the track and supports were 3D printed.
A Teensy microcontroller runs the whole show, with the LED strips split into five separate sections to allow a high enough frame rate for smooth animations. An infrared remote is used to start and stop the ride, as well as to adjust the speed; the model supports running the trains at a physically accurate speed, but because this looks rather dull, the regular setting is about three times as fast.
A Jack-In-The-Box is scary enough the first time. However, if you’ve seen the clown pop out before, it fails to have the same impact. [Franklinstein] decided that swapping out the clown for an alternative payload would deliver the fright he was after.
Inside the toy, an Arduino Nano runs the show. It’s paired with an airhorn, installed in a special frame along with an RC servo. When the time is right, the RC servo presses up against the airhorn, firing off an almighty noise. There’s also a confetti blaster, built with a small chamber full of compressed air. When a solenoid is released, the compressed air rushes out through a funnel full of confetti, spraying it into the room.
When the crank on the toy is turned, the typical song plays. When the lid of the box opens, it releases a switch, and the Arduino fires off the confetti and airhorn. It’s shocking enough for [Franklinstein] himself, and even more surprising for those expecting the toy’s typical bouncing clown instead.
If you can buy something off the shelf, there’s a good chance that someone has tried to 3D print their own version. [Daniel Norée] did just that with skateboard trucks, whipping up a design of his own.
The main body of the trucks is 3D-printed, as is the hanger. A 195 mm M8 threaded rod is then used through the center of the trucks in order to provide an axle for fitting the wheels and bearings themselves. He 3D-printed the parts using a carbon-fiber reinforced nylon with the slicer set up to maximize strength. In testing, they rolled around the neighbourhood just fine.
Those trucks ended up in the hands of [Braille Skateboarding], who put them through their paces. The trucks are loose, but take a good beating around the park. Eventually one of the trucks succumbs after landing many kickfilps and ollies on the concrete.
Sometimes you need to know the temperature of something from a ways away. That might be a smoker, a barbecue, or even a rabbit hutch. This project from [Discreet Mayor] might just be what you’re looking for.
It consists of a MAX31855 thermocouple amplifier, designed for working with commonly-available K-type thermocouples. This is hooked up to a Texas Instruments CC1312 microcontroller, which sends the thermal measurements out over the 802.15.4 protocol, the same which underlies technologies like Zigbee and Thread. It’s able to send radio messages over long distances without using a lot of power, allowing the project to run off a CR2023 coin cell battery. Combined with firmware that sleeps the system when it’s not taking measurements, [Discreet Mayor] expects the project to run up to several years on a single battery.
The messages are picked up and logged in a Grafana setup, where they can readily be graphed. For extra utility, any temperatures outside a preset range will trigger a smartphone alert via IFTTT.
Keeping a close eye on temperatures is a key to making good food with a smoker, so this project should serve [Discreet Mayor] well. For anyone else looking to monitor temperatures remotely with a minimum of fuss, it should also do well!
They say that if you have a lathe, you have every other machine tool too. To some degree, that’s true — you can make almost anything on a lathe, including another lathe, and even parts best made on other machine tools can usually be made on a lathe in a pinch. But after seeing this lathe attachment for a DIY electric discharge machining tool, we might be inclined to see the EDM as the one machine tool to rule them all.
Now, we’ll admit that the job [BAXEDM] built this tool for might be a little contrived. He wanted to make some custom hex inserts for his Swiss Army knife, which seem like they’d have been pretty easy to make from hex bar stock in a conventional lathe. Then again, hardened steel is the kind of material that wire EDM was made for, and there seem to be many use cases for an attachment that can spin a workpiece against an EDM cutting wire.
That was really the trick of this build — spinning a part underwater. To accomplish this, [BAXEDM] built a platform to carry a bearing block that supports a standard ER-25 collet, with a bracket that holds a stepper clear of the water in the EDM cutting tank. There are plenty of 3D printed insulators too, to keep most of the attachment electrically isolated from the EDM current, plus exotic parts like ceramic bearings that won’t corrode under water. There were a ton of other considerations, too; [BAXEDM] goes through the long iterative design process in the video below, as well as taking his new tool for a literal spin starting at about the 27:00 mark.
If you’re intrigued by what EDM can accomplish — and who wouldn’t be? — but you need more background on the process, we’ve got you covered.
When we think of a typical four stroke internal combustion engine, we think of metal. And for any type of longevity or performance, that’s certainly the right choice. But [Integza] wanted to see what happens inside a 4 stroke engine, and it wasn’t enough to see it from a transparent cylinder head. No, he wanted to see it in the cylinder itself. Thanks to advances in material sciences, he got his wish as seen in the video below the break.
While researching possible transparent materials to use as a cylinder on his model engine, he learned about resin polishing. Combining his newly learned resin polishing knowledge with his knowledge of 3D printing, [Integza] printed a new cylinder and polished the resin until it was transparent. The engine ran, but misfired terribly.
The experiment progressed into trying different fuels and learning the differences between them, as well as uncovering a new-to-him mystery: Why was the engine misfiring, and why did the different fuels act so dramatically different? Indeed, more learning and more experimenting is needed. But if you want to see the great sight of watching combustion take place in slo-mo, you have to check out the video below.
The early days of FDM 3D printing were wild and wooly. Getting plastic to stick to your build plate was a challenge. Blue tape and hairspray-coated glass were kings for a long time. Over time, better coatings have appeared and many people use spring steel covered in some kind of PEI. There seem to be fewer choices when it comes to resin printers, though. We recently had a chance to try three different build surfaces on two different printers: a Nova3D Bene4 and an Anycubic Photon M3. We learned a lot.
Resin Printing Review
If you haven’t figuratively dipped your toe into resin yet — which would literally be quite messy — the printers are simple enough. There is a tank or vat of liquid resin with a clear film on the bottom. The vat rests on an LCD screen and there is a UV source beneath that.