Testing An Inexpensive CNC Spindle

September 12, 2022 by Bryan Cockfield 22 Comments

The old saying “you get what you pay for” is a cautionary cliché, but is directly contrary to several other common sayings. In the case of [Spikee]’s planned CNC machine build, he took the more adventurous idiom of “no risk, no reward” to heart when he purchased these spindles for the machine from AliExpress. While the delivered product seemed fine, there were some problems that needed investigations.

Upon delivery of the spindle, everything seemed to work correctly out-of-the-box. Even the variable frequency drive, which was programmed at the factory, was working properly. But at around 8000 rpm the machine would begin shaking. The suspected part causing the vibration was the tool holder, so after checking the machine’s runout and also using a specialized vibration sensor this was confirmed to be the case.

Luckily [Spikee] was able to get a refund on the tool holders since they were out of spec, but still has a quite capable spindle on his hands for an excellent price. Without some skills in troubleshooting he might have returned the entire machine unnecessarily. If you are looking for some other ideas in setting up an inexpensive CNC machine, you might also like to look at BLDC motors from a remote control vehicle.

Jigsaw Puzzles Are Defeated

August 4, 2022 by Brian McEvoy 30 Comments

To some folx, puzzles are the ultimate single-player game, but to others, they are like getting a single Tootsie Roll on Halloween. [Shane] of Stuff Made Here must fall into the latter category because he spent the equivalent of 18 work-weeks to make a robot that solves them automatically. Shots have been fired in the war on puzzles.

The goal of this robot is to beat a hybrid idea of two devilish puzzles. The first is all-white which could be solved by taking a piece at random and then checking its compatibility with every unsolved piece. The second is a 5000-piece monster painted white. There is a Moby Dick theme here. Picking up pieces like a human with fingers is out of the question, but pick-and-place machines solved this long ago, and we learn a cool lesson about how shop-air can create negative pressure. Suction. We wonder if anyone ever repurposed canned air to create a vacuum cleaner.

The meat of this video is overcoming hurdles, like a rhomboidal gantry table, helping machine vision see puzzle pieces accurately, and solving a small puzzle. [Shane] explains the solutions with the ear of someone with a technical background but at a high enough level that anyone can learn something. All the moving parts are in place, but the processing power to decode the puzzle is orders of magnitude higher than consumer machines, so that will wait for part two.

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A 3D printed roller coaster model with light strips modelling the trains

How To Make A Model Roller Coaster Without Any Moving Parts

July 20, 2022 by Robin Kearey 5 Comments

Roller coasters are not only great fun to ride, they’re also fascinating pieces of engineering. Building your own full-size coaster is sadly beyond most people’s means, so the average enthusiast will have to settle for simulation or modelling of their own designs. [Jon Mendenhall] is one of those who specialize in building model roller coasters and simulating their motion in intricate detail. His latest project is a scale model of VelociCoaster, a Jurassic Park-themed ride in Universal’s Islands of Adventure, that simulates the coaster’s ride without using any moving parts.

[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.

Looking for more roller coaster models? [Jon] made a similarly impressive model with a powered train before, and we’ve seen several models that actually coast along their tracks.

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photo of the CNC controller, with the PLCC socket for the CPU, surrounded by driver ICs

Old CNC Brain Swapped With An Arduino

July 11, 2022 by Arya Voronova 12 Comments

[Sebastian] and [Stefan Shütz] had a ISEL EP1090 CNC machine at home, sitting unused, and they decided to bring it to life. With pretty good mechanical specs, this CNC looked promising – alas, it was severely constrained by its controller. The built-in CPU’s software was severely outdated, had subpar algorithms for motor driving programmed in, and communication with the CNC was limited because the proprietary ISEL communications protocol that isn’t spoken by other devices.The two brothers removed the CPU from its PLCC socket, and went on to wiring a grbl-fueled Arduino into the controller box.

They reverse-engineered the motor driver connections – those go through a 74HC245 buffer between the original CPU and the drivers. Initially, they put an Arduino inside the control box of the CNC and it fit nicely, but it turned out the Arduino’s CPU would restart every time the spindle spun up – apparently, EMC would rear its head. So, they placed the Arduino out of the box, and used two CAT7 cables to wire up the motor and endstop signals to it.

For tapping into these signals, they took the 74HC245 out of its socket, and made an interposer from two small protoboards and some pin headers – letting them connect to the STEP and DIR lines without soldering wires into the original PCB. There’s extensive documentation, GRBL settings, and more pictures in their GitHub repo, too – in case you have a similar CNC and would like to learn about upgrading its controller board!

After this remake, the CNC starts up without hassles. Now, the brothers shall CNC on! Often, making an old CNC machine work is indeed that easy, and old controller retrofits have been a staple of ours. You can indeed use an Arduino, one of the various pre-made controller boards like Gerbil or TinyG, or even a Raspberry Pi – whatever helps you bridge the divide between you and a piece of desktop machinery you ought to start tinkering with.

New Gear Saves Old Printer

July 5, 2022 by Jenny List 18 Comments

As the digital photographic revolution took off, and everyone bought a shiny new film-less camera, there was a brief fad for photo printers. The idea was you’d have the same prints you’d always had from film, but the media for these printers would invariably cost a fortune so consumers moved on pretty quickly.

Now the pop up in second-hand stores and the like, which is how [Amen] acquired a Canon Selphy 740. It didn’t work, and on investigation it was found that a particularly tiny plastic gear had failed. Most people would have tossed the printer in the trash, but they instead opted to CNC-machine a new gear. It’s not everyday you tackle a job this small, so it makes for an interesting tale.

While the first instinct might be to reach reach for a CAD package, [Amen] instead wrote a script to create the raw GCode. The machining is done with a 0.2 mm bit ground to the desired profile. The result: a gear that gets the printer working again. It’s a dye-sublimation printer that leaves a negative image in the cartridge, allowing negative prints to be made with a bit of cartridge rewinding. And for those who might have ended up with a Selphy of their own, there’s a further post about using cheaper aftermarket cartridges.

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Putting A Little More Juice In Your Emulation Station

June 22, 2022 by Matthew Carlson 9 Comments

After you’ve built a snazzy Raspberry Pi-powered retro gaming console, you might be wondering if you could have just a wee bit more power and run some of those other games you might remember, such as Xbox, Wii, or PS3. Perhaps in the future, a later revision of an RPi could handle it but currently, to emulate the 6th/7th generation of consoles, you need something a little beefier. Luckily, [Zac] got his hands on an old gaming laptop and turned it into his own game console.

The first step was to take the laptop apart and discard the parts not needed. [Zac] stripped away the battery, Bluray drive, and spinning hard disk. That left him with a much smaller PCB that could fit into a small case. The power button was integrated into the keyboard but came into the motherboard by the flat cable keyboard connection. So by bridging a few pins, he could power up the laptop. Next, he upgraded the RAM, wifi card, an NVMe drive, and redid all the thermal paste and putty to try and keep things cool while overclocking the GPU.

The case for the machine heavily used his CNC as it was walnut with a mid-section made of plywood. The top has a gorgeous cast acrylic window to see inside. The part the [Zac] was dreading with the fine pitch soldering. Ultimately he got both wires connected with good connections and no bridging. Because it’s just a PC at its heart, almost every game is on the table. Emulation, some more moderate PC games, streaming from his office PC, and cloud gaming services allow him to access most games made. We love the concept and the idea.

We love the aesthetic of the build but if you prefer to keep your consoles looking a little more faithful, why not put your mini PC inside of an actual N64 case? Video after the break.

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Wooden You Like To Hear A CNC-Cut Phonograph Record?

June 17, 2022 by Dan Maloney 22 Comments

Say what you will about [Thomas Edison], but it’s hard to deny the genius of his self-proclaimed personal favorite invention: the phonograph. Capturing sound as physical patterns on a malleable medium was truly revolutionary, and the basic technology that served as the primary medium of recorded sound for more than a century and built several major industries is still alive and kicking today.

With so much technological history behind it, what’s the aspiring inventor to do when the urge to spin your own phonograph records strikes? Easy — cut them from wood with a CNC router. At least that’s how [alnwlsn] rolled after the “one-percent inspiration” hit him while cutting a PCB with his router. Reasoning that the tracks on the copper were probably about as fine as the groove on a record, he came up with some math to describe a fine-pitch spiral groove and overlay data from a sound file, and turn the whole thing into G-code.

For a suitable medium, he turned to the MDF spoil board used to ship PCB stencils, which after about three hours of milling resulted in a rather hairy-looking 78-RPM record. Surprisingly, the record worked fairly well on a wind-up Victrola. The spring-powered motor was a little weak for the heavy wooden record and needed a manual assist, but you can more or less clearly hear the 40-second recording. Even more surprising was how much better the recording sounded when the steel needle was replaced with a chunk of toothpick. You can check out the whole thing in the video below, and you’ll find the G-code generation scripts over on GitHub.

Is all this talk about reproducing music using wiggly lines confusing you? Woah, there, whippersnapper — check out [Jenny]’s primer for the MP3 generation for the background you need.

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