Working with CAD programs involves focusing on the task at hand and keyboard shortcuts can be very handy. Most software packages allow the user to customize these shortcuts but eventually, certain complex key combination can become a distraction.
[awende] over at Sparkfun has created a Cherry MX Keyboard which incorporates all of the Autodesk Eagle Shortcuts to a single 4×4 matrix. The project exploits the Arduino Pro Mini’s ability to mimic an HID device over USB thereby enabling the DIY keyboard. Pushbuttons connected to the GPIOs are read by the Arduino and corresponding shortcut key presses are sent to the host machine.
Additional functionality is implemented using two rotary encoders and the Teensy encoder library. The first knob functions as a volume control with the push-button working as a mute button. The encoder is used to control the grid spacing and the embedded button is used to switch between imperial and metric units. The entire code, as well as the schematic, is available on GitHub for your hacking pleasure. It’s a polished project just ready for you to adapt.
[3D Hubs] have shared a handy guide on designing practical and 3D printing-friendly enclosures. The guide walks through the design of a two shell, two button remote control enclosure. It allows for a PCB mounted inside, exposes a USB port, and is optimized for 3D printing without painting itself into a corner in the process. [3D Hubs] uses Fusion 360 (free to hobbyists and startups) in their examples, but the design principles are easily implemented with any tool.
One of the tips is to design parts with wall thicknesses that are a multiple of the printer’s nozzle diameter. For example, a 2.4 mm wall thickness may sound a bit arbitrary at first, but it divides easily by the typical FDM nozzle diameter of 0.4 mm which makes slicing results more consistent and reliable. Most of us have at some point encountered a model where the slicer can’t quite decide how to handle a thin feature, delivering either a void between perimeters or an awkward attempt at infill, and this practice helps reduce that. Another tip is to minimize the number of sharp edges in the design, because rounded corners print more efficiently and with smoother motions from the print head.
We often wonder how many people have 3D printers and wind up just printing trinkets off Thingiverse. To get the most out of a printer, you really need to be able to use a CAD package and make your own design. However, just like a schematic editor doesn’t make your electronic designs work, a CAD program won’t ensure you have a successful mechanical part.
[TheGoofy] has a 100% 3D printed vise that looks like it is useful. What’s really interesting, though, is the video (see below) where he explains how printing affects material strength and other design considerations that went into the vise.
In the world of late-stage capitalism, unchecked redistribution of wealth to the upper classes has led to the development of so-called ultraluxury watches. Free from any reasonable constraints on material or R&D cost, manufacturers are free to explore the outer limits of the horological art. [Karel] is an aspiring engineer and watch enthusiast, and has a taste for the creations of Urwerk. They decided to see if they could create a replica of the UR202 watch with nothing more than the marketing materials as a guide.
[Karel]’s first job was to create a model of the watch in CAD. For a regular watch this might be simple enough, but the UR202 is no run-of-the-mill timepiece. It features a highly irregular mechanism, full of things like a turbine regulated winding mechanism, telescoping rods instead of minute hands, and tumbling rotors to indicate the hours. The official product sheet bears some of these features out. Through careful analysis of photos and watching videos frame-by-frame, they managed to recreate what they believe to be a functioning mechanical model within their CAD software.
It was then time to try and build the timepiece for real. It was then that [Karel] started hitting some serious stumbling blocks. As a humble engineering student, it’s not often possible to purchase an entire machine shop capable of turning out the tiny, precision parts necessary to make even a basic watch mechanism. Your basic 3D printer squirting hot plastic isn’t going to cut it here. Farming out machining wasn’t an option as the cost would be astronomical. [Karel] instead decided on combining a Miyota movement with a machined aluminum base plate and parts 3D printed using a process known as “Multijet Modelling” which essentially is an inkjet printhead spitting out UV curable polymer.
In the end, [Karel] was able to get just the tumbling hour indicator working. The telescoping minute hand, compressed air turbine winding system, and other features didn’t make it into the build. However, the process of simulating these features within a CAD package, as well as manufacturing a semi-functional replica of the watch, was clearly a powerful learning experience. [Karel] used their passion to pursue a project that ended up giving them a strong grasp of some valuable skills, and that is something that is incredibly rewarding.
We’re used to the relationship between the commercial software companies from whom we’ve bought whichever of the programs we use on our computers, and ourselves as end users. We pay them money, and they give us a licence to use the software. We then go away and do our work on it, create our Microsoft Word documents or whatever, and those are our work, to do whatever we want with.
There are plenty of arguments against this arrangement from the world of free software, indeed many of us choose to heed them and run open source alternatives to the paid-for packages or operating systems. But for the majority of individuals and organisations the commercial model is how they consume software. Pay for the product, use it for whatever you want.
Until recently, computer-aided design (CAD) software was really only used by engineering companies who could afford to pay thousands of dollars a year per license. The available software, while very powerful, had a very high learning curve and took a lot of training and experience to master. But, with the rise of hobbyist 3D printing, a number of much more simple CAD programs became available.
While these programs certainly helped makers get into 3D modeling, most had serious limitations. Only a few have been truly open-source, and even fewer have been both open-source and parametric. Parametric CAD allows you to create 3D models based on a series of parameters, such as defining a cube by its origin and dimensions. This is in contrast to sculpting style 3D modeling software, which is controlled much more visually. The benefit of parametric modeling is that parameters can be changed later, and the model can be updated on the fly. Features can also be defined mathematically, so that they change in relation to each other.
Today’s engineers are just as good as the ones that came before, but that should not be the case and there is massive room for improvement. Improvement that can be realized by looking for the best of the world to come and the one we left behind.
Survivorship bias is real. When we look at the accomplishments of the engineers that came before us we are forced to only look at the best examples. It first really occurred to me that this was real when I saw what I still consider to be the most atrocious piece of consumer oriented engineering the world has yet seen: the Campbell’s soup warmer.
This soup warmer is a poor combination of aluminum and Bakelite forged into the lowest tier of value engineering during its age. Yet it comes from the same time that put us on the moon: we still remember and celebrate Apollo. It’s possible that the soup warmer is forgotten because those who owned it perished from home fires, electrocution, or a diet of Campbell’s soup, but it’s likely that it just wasn’t worth remembering. It was bad engineering.
In fact, there’s mountains of objects. Coffee pots whose handles fell off. Switches that burned or shocked us. Cars that were ugly and barely worked. Literal mountains of pure refuse that never should have seen the light of day. Now we are here.
The world of engineering has changed. My girlfriend and I once snuck into an old factory in Louisville, Kentucky. The place was a foundry and the only building that survived the fire that ended the business. It happened to be where they stored their professional correspondence and sand casting patterns. It was moldy, dangerous, and a little frightening but I saw something amazing when we cracked open one of the file cabinets. It was folders and folders of all the communication that went into a single product. It was an old enough factory that some of it was before the widespread adoption of telephony and all documents had to be mailed from place to place.