A classic problem. You have a new CPU and a 15-year old water cooling system. Of course, the bracket doesn’t fit. Time to buy a new cooler? Not if you are [der8auer]. You design a new bracket and mill it out of aluminum.
Honestly, it might seem overkill, but it makes sense. After all, no matter how new the CPU is, using water to cool it still works the same way, in principle.
The semiconductor shortage sparked by the pandemic is showing no signs of slowing down. Although auto manufacturers were some of the first affected, the shortage has now spread and is impacting all sorts of projects, including the Smoothieboard open-source CNC controllers.
[Chris Cecil] walks through the production woes they’ve had over the last few months. It began this spring with a batch of the V1.1 boards. The prices of some of their chips started jumping, and then they were informed that the microcontroller that serves as the brains of the Smoothieboard was only available for five times the old price. In the end, they placed a smaller order, and V1.1 Smoothieboards will likely be scarce until the microcontroller’s price returns to normal.
Getting V2 of the boards into production has been even more difficult. Just weeks before the final prototype, it was discovered that the LPC4330 microcontroller the V2 was built around was also sold out worldwide. With the shortage in mind, a hole was left in the layout of the final version of V2 so that they could finish the design around whatever microcontroller they were able to get. In the end, they were able to lock down a supply of STM32H745 controllers, which are actually substantially more capable than the original device.
If you’re interested in the origins of the chip shortage, this article from January is a good place to start. This isn’t the first time parts shortages have wreaked havoc on the world of electronics—does anyone remember the global resistor shortage of ’18?
CNC mills will never match real heavy metal mills on hard materials, but that won’t stop people from pushing the limits of these DIY machines. One of the usual suspects, [Ivan Miranda] is at it again, this time building a knee mill from aluminum extrusions and 3D printed fittings. (Video after the break.)
Most DIY CNC milling machines we see use a gantry arrangement, where the bed is fixed while everything else moves around it. On most commercial metal milling machines, the table is the moving part, and are known as knee mills. In the case of [Ivan]’s mill, the table can move 187 mm on the X-axis and 163 mm on the Y-axis. The 1.5 kW spindle can move 87 mm in the Z-axis. All axes slide on linear rails and are driven by large stepper motors using ball screws. The table can also be adjusted in the Z-direction to accept larger workpieces, and the spindle can be tilted to mill at an angle.
To machine metal as [Ivan] intended, rigidity is the name of the game, and 3D printed parts and aluminum extrusion will never be as rigid as heavy blocks of steel. He says claims that the wobble seen on the video is due to the uneven table on which the mill was standing. Of course, a wobbly base won’t be doing him any favors. [Ivan] also had some trouble with earthing on the spindle. He nearly set his workshop on fire when he didn’t notice tiny sparks between the cutter and aluminum workpiece while he was cooling it with isopropyl alcohol. This was solved with the addition of the grounding wire.
While the machine does have limitations, it does look like it can machine functional metal parts. It could even machine metal upgrades for its 3D printed components. One possible way to improve rigidity would be to cast the frame in concrete. [Ivan] has built several other workshop tools, including a massive 3D printer and a camera crane. Continue reading “3D Printed CNC Knee Mill”
Some might look at a cheap inkjet printer and see a clunky device that costs more to replace the ink than to buy a new one. [Abhishek Verma] saw an old inkjet printer and instead saw a smooth gantry and feed mechanism, the perfect platform to build his own DIY vinyl cutter.
The printer was carefully disassembled. The feed mechanism was reworked to be driven by a stepper motor with some 3D printed adapter plates. A solenoid-based push/pull mechanism for the cutting blade was added with a 3D printed housing along with a relay module. An Arduino Uno takes in commands from a computer with the help of a CNC GRBL shield.
What we love about this build is the ingenuity and reuse of parts inside the old printer. For example, the old PCB was cut and connectors were re-used. From the outside, it’s hard to believe that HP didn’t manufacture this as a vinyl cutter.
If you don’t have a printer on hand, you can always use your CNC as a vinyl cutter. But if you don’t have a CNC, [Abhishek] shares all the STL files for his cutter as well as the schematic. Video after the break.
The longevity of plastic is both a blessing and a curse. On the one hand, it’s extremely durable, inexpensive, and easy to work with, but it also doesn’t biodegrade and lasts indefinitely in the environment when not disposed of properly. While this can mean devastating impacts to various ecosystems, it can also be a benefit if you happen to pick this plastic up and also happen to have a laser cutter around.
After cleaning and sorting plastic that they had found from various places, including scraps from a 3D printing facility, the folks at [dinalab] set about turning waste plastic into something that would be usable once more. After sorting it they shredded it and then melted it into sheets. They found that a sandwich press yielded the best results, as it kept the plastic at a low enough temperature to keep it from burning. Once its off of the press and properly cooled, the flat sheets of plastic can be sent to the laser cutter to be made into whatever useful thing they happen to need.
Not only does this process reuse plastic that would otherwise end up in the landfill (or worse, the ocean), it can also reuse plastic from itself since the scraps can be re-melted back into sheets. Plastic does lose some of its favorable material properties with repeated heat cycles, but we’d have to imagine this is negligible for the types of things that [dinalab] is creating. Of course, you can always skip the heat cycles entirely and turn waste plastic directly into 3D printer filament instead.
Continue reading “Discarded Plastic Laser-Cut And Reassembled”
[T-Kuhn]’s Octo-Bouncer platform has learned some new tricks since we saw it last. If you haven’t seen it before, this device uses computer vision from a camera mounted underneath its thick, clear acrylic platform to track a ball in 3D space, and make the necessary (and minute) adjustments needed to control the ball’s movements with a robotic platform in real time.
We loved the Octo-Bouncer’s mesmerizing action when we saw it last, and it’s only gotten better. Not only is there a whole new custom ball detection algorithm that [T-Kuhn] explains in detail, there are also now visualizations of both the ball’s position as well as the plate movements. There’s still one small mystery, however. Every now and again, [T-Kuhn] says that the ball will bounce in an unexpected direction. It doesn’t seem to be a bug related to the platform itself, but [T-Kuhn] has a suspicion. Since contact between the ball and platform is where all the control comes from, and the ball and platform touch only very little during a bounce, it’s possible that bits of dust (or perhaps even tiny imperfections on the ball’s surface itself) might be to blame. Regardless, it doesn’t detract from the device’s mesmerizing performance.
Design files and source code are available on the project’s GitHub repository for those who’d like a closer look. It’s pretty trippy watching the demonstration video because there is so much going on at once; you can check it out just below the page break.
Continue reading “Robotic Ball-Bouncing Platform Learns New Tricks”
Here’s an interesting experiment that attempts to measure the quality of a linear rail by using a form of visual odometry, accomplished by mounting a camera on the rail and analyzing the video with open-source software usually used to stabilize shaky video footage. No linear rail is perfect, and it should be possible to measure the degree of imperfection by recording video footage while the camera moves down the length of the rail, and analyzing the result. Imperfections in the rail should cause the video to sway a proportional amount, which would allow one to characterize the rail’s quality.
To test this idea, [Saulius] attached a high-definition camera to a linear rail, pointed the camera towards a high-contrast textured pattern (making the resulting video easier to analyze), and recorded video while moving the camera across the rail at a fixed speed. The resulting video gets fed into the Deshaker plugin for VirtualDub, of which the important part is the deshaker.log file, which contains X, Y, rotate, and zoom correction values required to stabilize the video. [Saulius] used these values to create a graph characterizing the linear rail’s quality.
It’s a clever proof of concept, especially in how it uses no special tools and leverages a video stabilizing algorithm in an unusual way. However, the results aren’t exactly easy to turn into concrete, real-world measurements. Turning image results into micrometers is a matter of counting pixels, and for this task video stabilizing is an imperfect tool, since the algorithm prioritizes visual results instead of absolute measurements. Still, it’s an interesting experiment, and perfectly capable of measuring rail quality in a relative sense. Can’t help but be a bit curious about how it would profile something like these cardboard CNC modules.
