Getting into a big electronics project often involves the use of specialized tools, namely the use of some sort of soldering iron or other way to apply solder to often intricate, tiny, and heat-sensitive parts. While it’s best to learn to pick up this skill at some point, it’s not always necessary, even for big, complicated projects like [DerULF1]’s full 8-bit computer that he built entirely on breadboards.
For a fully featured 8-bit computer, this build goes deep into the details of how the computer works. The clock allows programs to be stepped through one cycle at a time, and even the memory can be individually accessed with a set of switches. There are plenty of other interesting features as well, such as using registers to access extra memory. It features an SPI port and PS/2 keyboard controller and also loads programs from an SD card.
The build was inspired by some of [Ben Eater]’s projects which famously focus on using logic gates and TTL chips to perform complex tasks, such as another breadboard computer which plays snake on a small display. It’s certainly a great way to learn about the inner function of computers, and better still that no soldering is required. But you may need a few extra breadboards.
The Elegoo Mars is an affordable SLA (resin-based) 3D printer, and there are probably few that have seen more mods and experimentation than [Jan Mrázek]’s machine. The final design of his DIY flexible build plate is a refinement of his original proof of concept, which proved a flexible build platform can be every bit as useful on an SLA printer as it is for FDM; instead of chiseling parts off a rigid build platform, simply pop the flexible steel sheet off the magnetic base and flex it slightly for a much easier part removal process. His original design worked, but had a few rough edges that have since been ironed out.
We love how [Jan] walks through all of the design elements and explains what worked and what didn’t. For example, originally he used a galvanized steel sheet which was easy enough to work with, but ended up not being a viable choice because once it’s bent, it stays bent. Spring steel is a much better material for a flexible build platform, but is harder for a hobbyist to cut.
Fortunately, it’s a simple job for any metal fabrication shop and [Jan] got a variety of thicknesses cut very cheaply. It turns out that the sweet spot is 0.3 mm (although 0.2 mm is a better choice for particularly fragile parts.) [Jan] also suggests cutting the sheet a few millimeters larger than the build platform; it’s much easier to peel the sheet off the magnetic base when one can get a fingertip under an edge, after all.
The magnetic base that the steel sheet sticks to is very simple: [Jan] converted a stock build platform by mounting an array of 20 x 20 x 1 mm magnets with 3M adhesive mounting tape. He was worried that resin might seep in between the magnets and cause a problem, perhaps even interfering with the adhesive; but so far it seems to be working very well. Resin is viscous enough that it never penetrates far into the gaps, and no effect on the adhesive has been observed so far.
Watch how easily parts are removed in the short video embedded below, in which [Jan] demonstrates his latest platform design.
SLA printing in resin is great, but part washing can be a hassle. The best results come from a two-stage wash, but that also means more material and more processing steps. Fortunately, there are ways to make it easier and more effective. One such way is to use a part washing machine, and I’ll cover a DIY option to make your own, but despite what the advertising implies for the commercial ones, a wash machine isn’t a cure-all.
Let’s go through how to get the best results from part washing, how to make the solvent last as long as possible, and how to dispose of the eventual waste.
Resin-Printed Parts Need Washing
All parts printed in resin emerge from the printer coated in syrupy, uncured goop. This needs to be removed completely, or the print ends up sticky and no amount of drying or additional UV curing will change that. (There is a way to fix sticky prints, but it’s better to avoid the situation in the first place.)
Simple part washing can be done with nothing more than a jar in which to rinse and soak a small part for about ten minutes, but agitation and a secondary wash will go a long way toward better and more consistent results. As mentioned, part washing machines like to present themselves as a one-appliance solution, but best results still come from a two-stage wash, and that means some additional steps.
Plenty of projects we see here could easily be purchased in some form or other. Robot arms, home automation, drones, and even some software can all be had with a quick internet search, to be sure. But there’s no fun in simply buying something when it can be built instead. The same goes for tools as well, and this homemade drill press from [ericinventor] shows that it’s not only possible to build your own tools rather than buy them, but often it’s cheaper as well.
This mini drill press has every feature we could think of needing in a tool like this. It uses off-the-shelf components including the motor and linear bearing carriage (which was actually salvaged from the Z-axis of a CNC machine). The chassis was built from stock aluminum and bolted together, making sure to keep everything square so that the drill press is as precise as possible. The movement is controlled from a set of 3D printed gears which are turned by hand.
The drill press is capable of drilling holes in most materials, including metal, and although small it would be great for precision work. [ericinventor] notes that it’s not necessary to use a separate motor, and that it’s possible to use this build with a Dremel tool if one is already available to you. Either way, it’s a handy tool to have around the shop, and with only a few modifications it might be usable as a mill as well.
The hardware and software required to make DIY keyboards happen has gotten more and more accessible, and that means it’s easier than ever to make one’s ideal input device a reality from the ground up. For [Cameron Sun], his Ellipsis Split mechanical keyboard buildlog details his second effort, refining his original design from lessons learned the first time around. The new keyboard is slim, split into two, and has integrated wrist supports made from stained wood. The painting and wood treatment took a lot of work and patience, but it certainly paid off because the result looks amazing!
When we saw [Cameron]’s first custom keyboard, we admired the unique aluminum case and some nice touches like the physical toggle switches. Those tactile switches allow changing the keyboard to different modes, while also serving as a visual indicator. [Cameron] liked those switches too, but alas they just didn’t fit into the slim new design. However, he’s very happy with swapping modes in software and using a small OLED display as an indicator. What kind of different modes does his keyboard have? There’s Windows mode and Mac mode (which changes some hotkeys) as well as modes that change which keys in the thumb clusters do what (moving the space key to the left for easier gaming, for example.) After all, it’s not just the physical layout that can be customized with a DIY keyboard.
Interested in making your own custom keyboard? Be sure to look into this breakaway keyboard PCB concept before you start, because it just might make your custom build a lot easier.
Need to cut threads into a hole? A tool called a tap is what you need, and a hand-operated one like the one shown here to the side is both economical and effective. A tap’s cutting bit works by going into a pre-drilled hole, and it’s important to keep the tool straight as it does so. It’s one thing to tap a few holes with steady hands and a finely calibrated eyeball, but when a large number of holes need to be tapped it can be worth getting a little help.
We have seen quite a few DIY joystick designs that use Hall effect sensors, but [Akaki]’s controller designs (YouTube video, embedded below) really make the most of 3D printing to avoid the need for any other type of fabrication. He’s been busy using them to enhance his Microsoft Flight Simulator 2020 experience, and shares not just his joystick design, but makes it a three-pack with designs for throttle and pedals as well.
Hall effect sensors output a voltage that varies in proportion to the presence of a magnetic field, which is typically provided by a nearby magnet. By mounting sensors and magnets in a way that varies the distance between them depending on how a control is moved, position can be sensed and communicated to a host computer. In [akaki]’s case, that communication is done with an Arduino Pro Micro (with ATmega32U4) whose built-in USB support allows it to be configured and recognized as a USB input device. The rest is just tweaking the physical layouts and getting spring or elastic tension right. You can see it all work in the video below.