It’s very likely that a majority of readers will have had a gear fail in a piece of equipment, causing it to be unrepairable. This is a problem particularly with plastic gears, which shed teeth faster than a child who has discovered the financial returns of the Tooth Fairy.
[BcastLar] has a shredder with a gear that has, well, shredded. He’s posted a video series over three parts that while ostensibly about fixing his shredder, is in reality a three-part tutorial on how to create custom gears using FreeCAD. While the principles of a gear are readily apparent to most observers their intricacies hide significant complexity which he does a great job of explaining. How to measure the parameters of a given gear, explaining mysteries such as pitch angle or beta, he breaks everything down in easy to understand steps.
His tool of choice is FreeCAD, and while he explains that FreeCAD has the ability to make gears from scratch the tool employed in the videos is the Gear Workbench plugin. He shows how this software removes the complexity of creating a gear, and shows the process on his screen as he creates the custom shredder part.
Finally, the process of 3D printing the gear is explained. You might ask why not machine it, to which he responds that tooling for non-standard gear profiles is prohibitively expensive. We’ve placed all three videos below the break, and we think you might want to make yourself a cup of tea or something and work through them.
The obsession with over-the-top-hardware conference badges means that we as attendees get to enjoy a stream of weird and wonderful electronic gadgets. But for the folks putting these conferences on, getting a badge designed and manufactured in time for the event can be a stressful and expensive undertaking. To keep things on track, the designs will often cut corners and take liberties that you’d never see in commercial products. But of course, that’s part of their charm.
As a case in point, the OLED display on the 2019 KiCon badge is held on with just four soldered header pins, and can easily be bent or even snapped off. So [Jose Ignacio Romero] took it upon himself to develop a 3D printable mount which integrates with the PCB and gives the display some mechanical support. Any KiCon attendees who are looking to keep their badge in peak fighting condition for the long haul might want to start warming their extruders.
The design of this upgrade was made all the easier thanks to the fact that the KiCon badge is (naturally) open hardware. That meant [Jose] could import the PCB files directly into FreeCAD and have a virtual model of the badge to work with. This let him check the clearances and position of components without having to break out the calipers and measure the real thing.
Playing around with the virtual assembly, [Jose] quickly realized that the mounting holes in the OLED display don’t actually line up with the holes in the PCB; potentially why the screen didn’t get mounted on the final hardware. Once this misalignment was characterized, he was able to factor it into his design: the PCB side gets screwed down, and the screen snaps into printed “nubs” on the top of the mount.
Eagle and Fusion are getting all the respect for integrating electronic and mechanical design, but what about KiCad? Are there any tools out there that allow you to easily build an enclosure for your next printed circuit board? [Maurice] has one solution, and it seamlessly synchronizes KiCad and FreeCAD. KiCad will give you the board, FreeCAD will give you the enclosure, and together you have full ECAD and MCAD synchronization.
This trick comes in the form of a FreeCAD macro (on the Github, with a bunch of documentation) that loads a KiCad board and components into FreeCAD and export them as a STEP file. You can align the KiCad board in FreeCAD, convert STEPs to VRMLs, check interference and collision, and create an enclosure around a KiCad board.
KiCad has gotten some really great visualization tools over the past few years, and we would be remiss if we didn’t mention it’s one of the best ways to visualize a completed circuit board before heading to production. Taking that leap from electronic CAD to mechanical CAD is still something that’s relatively rare in the KiCad ecosystem, and more tools to make this happen is always wanted.
The inaugural KiCon conference is kicking off this Friday in Chicago, and KiCad aficionados from all over the world are gathering to discuss anything and everything about the cross-platform, open-source electronic design automation platform. As you’d expect, Hackaday will have a presence at the conference, including a meet and greet after party. There’ll also be talks by a couple of our writers, including Anool Mahidharia, who’ll be taking time out of his trip to the States to drop by the Hack Chat with a preview of his talk, entitled “Fast 3D Model Creation with FreeCAD”.
Join us for the KiCad and FreeCAD Hack Chat this week with your questions about KiCad and FreeCAD. If you’ve got some expertise with electronic design tools, make sure you come by and contribute to the discussion too — we’d love to hear your insights. And as always, you can get your questions queued up by leaving a comment on the KiCad and FreeCAD Hack Chat event page and we’ll put them on the list for the Hack Chat discussion.
Click that speech bubble to the right, and you’ll be taken directly to the Hack Chat group on Hackaday.io. You don’t have to wait until Wednesday; join whenever you want and you can see what the community is talking about.
File this one away for your mad scientist costume next Halloween: [bitluni]’s Pocket Jacob’s Ladder is the perfect high voltage accessory for those folks with five dollars in parts, a 3D printer, and very big pockets.
[bitluni]’s video shows you all the parts you’ll need and guides you through the very simple build process. For parts, you’ll require a cheap and readily-available high-voltage transformer, a battery holder, some silver wire for the conductors, and a few other minor bits like solder and a power switch.
Once the electronics are soldered together, they’re stuffed inside a 3d printed case that [bitluni] designed with FreeCAD. The FreeCAD and STL files are all available on Thingiverse. We’re not sure what type of jar [bitluni] used to enclose the electrodes. If your jar isn’t a match, you’ll have to get familiar with FreeCAD or start from scratch with your favorite CAD package.
Either way, we enjoy the slight nod toward electrical safety and the reuse of household objects for project enclosures.
Let’s get this out of the way first – this project isn’t meant to be a replacement for your regular smartphone. Although, at the very least, you can use it as one if you’d like to. But [Shree Kumar]’s Hackaday Prize 2018 entry, the Kite : Open Hardware Android Smartphone aims to be an Open platform for hackers and everyone else, enabling them to dig into the innards of a smartphone and use it as a base platform to build a variety of hardware.
When talking about modular smartphones, Google’s Project Ara and the Phonebloks project immediately spring to mind. Kite is similar in concept. It lets you interface hacker friendly modules and break out boards – for example, sensors or displays – to create your own customized solutions. And since the OS isn’t tied to any particular brand flavor, you can customize and tweak Android to suit specific requirements as well. There are no carrier locks or services to worry about and the bootloader is unlocked.
At the core of the project is the KiteBoard – populated with all the elements that are usually stuffed inside a smartphone package – Memory, LTE/3G/2G radios, micro SIM socket, GPS, WiFi, BT, FM, battery charging, accelerometer, compass, gyroscope and a micro SD slot. The first version of KiteBoard was based around the Snapdragon 410. After some subtle prodding at a gathering of hackers in Bangalore, [Shree] moved over to the light side, and decided to make the KiteBoard V2 Open Source. The new board will feature a Snapdragon 450 processor among many other upgrades. The second PCB in the Kite Project is a display board which interfaces the 5″ touchscreen LCD to the main KiteBoard. Of Hacker interest is the addition of a 1080p HDMI output on this board that lets you hook it up to external monitors easily and also allows access to the MIPI DSI display interface.
Finally, there’s the Expansion Board which provides all the exciting hacking possibilities. It has a Raspberry Pi compatible HAT connector with GPIO’s referenced to 3.3 V (the KiteBoard works at 1.8 V). But the GPIO’s can also be referenced to 5 V instead of 3.3 V if you need to make connections to an Arduino, for example. All of the other phone interfaces are accessible via the expansion board such as the speaker, mic, earpiece, power, volume up / down for hacking convenience. The Expansion board also provides access to all the usual bus interfaces such as SPI, UART, I²C and I²S.
To showcase the capabilities of the Kite project, [Shree] and his team have built a few phone and gadget variants. Build instructions and design files for 3D printing enclosures and other parts have been documented in several of his project logs. A large part of the BoM consists of off-the-shelf components, other than the three Kite board modules. If you have feature requests, the Kite team is looking to hear from you.
When it comes to smartphone design, Quantity is the name of the game. Whether you’re talking to Qualcomm for the Snapdragon’s, or other vendors for memory, radios, displays and other critical items, you need to be toeing their line on MOQ’s. Add to this the need to certify the Kite board for various standards around the world, and one realizes that building such a phone isn’t a technical challenge as much as a financial one. The only way the Kite team could manage to achieve their goal is to drum up support and pledges via a Kickstarter campaign to ensure they have the required numbers to bring this project to fruition. Check them out and show them some love. The Judges of the Hackaday Prize have already shown theirs by picking this project among the 20 from the first round that move to the final round.
FreeCAD is a fairly sophisticated, open-source, parametric 3D modeler. The open-source part means that you can bend it to your will. [Alexandre] is working on a module that lets him easily add tabs, finger joints, and t-slots to models (YouTube link, embedded down under).
Right now the plugin is still experimental, but it looks usable. In the video demo, [Alexandre] builds up a simple box, and then adds all manner of physical connective pieces to it. You’ll note that the tabs look like they’re pieces added on to the main face — that’s because they are! He then exports the outlines to SVG and erases the lines that separate the tabs from the sides, and hands these files off to his laser cutter. Voilà! A perfect tab-and-t-slot box, with only a little bit of hand-work. ([Alexandre] mentions that it’s all still very experimental and that you should check out your design before sending it to the laser.)