The Raspberry Pi is a great platform for running retro video games, and with the addition of some buttons, a TFT screen and some speakers it’s relatively inexpensive and easy to get a working console up and running. If you have access to even a cheap 3D printer, a good-looking DIY console is well within reach for not a lot of money. YouTube user [DIY Engineering] has a bunch of consumer-grade fabrication tools and has designed and built a high-end but still DIY RetroPi gaming console, the RKDR II.
Among the tools that [DIY Engineering] has are both a FDM and DLP 3D printer, a reflow oven, a couple of different CNC machines and a laser cutter. They are all consumer grade, but not necessarily cheap – especially combined! [DIY Engineering] uses Fusion3D to model the case, bezel and circuit board, the latter of which is a 4 layer board designed in Eagle and sent off to be fabbed. The buttons, D-pad, screen and battery are bought off the shelf, but everything else is DIY. Check out the video for the details – the tools used, and the design files, are linked in the information section under the video on YouTube.
If you want to make serious assemblies out of 3D printed parts, you’ll eventually need to deal with threading. The easiest way is to make a nut trap that you can either insert a standard nut into after printing or even during printing. However, there are limitations to this method. If you want a real threaded part you can print the thread, cut the thread with a tap or bolt, or use a threaded insert. [Stefan] ran some tests to see how each of those methods held up to real use. (YouTube, embedded below.) He used fifty test parts to generate data for comparison.
We like the threaded insert method where a brass insert is pushed into the plastic while hot. Special features in the insert cause the brass part to grab the plastic, making it difficult to pull the insert out or twist it within the hole. Another thing we liked was that the tests used holes printed in the horizontal and vertical plane. You can clearly see that the orientation does alter how the holes work and fail to work.
It may seem a paradox, but in the future tiny computers may dump electronics and return to their mechanical roots. At the macroscale, mechanical computers are fussy and slow, but when your area is down to a few molecules, electronics have trouble working but mechanical systems do just fine. In addition, these devices don’t use electricity directly, don’t generate electronic signatures, and may be less sensitive to things like radiation that damage electronics. A recent paper in Nature Communications discusses how to 3D print common logic gates using both macro-scale 3D printing techniques and a much smaller version with microstereolithography. You can see a video of gates in action below.
The gates use a bistable flexible mechanism. The larger gates use ABS plastic and measure about 250mm square. The smaller gate measures less than 25 mm square. They also use a special technique to make gates as small as 100 microns theoretically possible, although some of that is future work for the team.
We can make our 3D-printed parts even more capable when we start mixing them with some essential “mechanical vitamins.” By combining prints with screws, nuts, fasteners, and pins, we get a rich ecosystem for mechanism-making with capabilities beyond what we could simply print alone.
Today I’d like to share some tips on one of my favorite functional 3D-printing techniques: adding heat-set inserts. As someone who’s been installing them into plastic parts for years manually, I think many guides overlook some process details crucial to getting consistent results.
Make no mistake; there are a handful of insert guides already out there [1, 2]. (In fact, I encourage you to look there first for a good jump-start.) Over the years though, I’ve added my own finishing move (nothing exotic or difficult) which I call the Plate-Press Technique that gives me a major boost in consistency.
Join me below as I fill in the knowledge gaps (and some literal ones too) to send you back to the lab equipped with a technique that will give you perfectly-seated inserts every time.
Having a great word processor won’t actually help you write the next bestselling novel. It might make it easier, but if you have a great novel in you, you could probably write it on paper towels with a crayon if you had to. A great 3D printer isn’t all you need to make great 3D prints. A lot depends on the model you start with and that software known as a slicer. You have several choices, and now you have one more: PathIO, a slicer sponsored by E3D, is out in beta. You can see a video about its features below.
The software has a few rough edges as you might expect from a beta. The slicer doesn’t feed Gcode to a printer directly, although Octoprint integration is forthcoming. Developers say they are focusing on the slicing engine which is totally new. According to their website, conventional slicers immediately cut a model into 2D slices and then decide how to realize each slice with respect to the shell and infill. Pathio works in 3D space and claims this has benefits for producing correct wall thickness and an increase in self-supporting geometries.
[Steve Martin] used to do a comedy act about “Let’s get small!” You have to wonder if [Paul Klinger] is a fan of that routine, as he recently completed a very small 3D printed PC that plays snake. Ok, it isn’t really a PC and it isn’t terribly practical, but it is really well executed and would make a great desk conversation piece. You can see the thing in all its diminutive glory in the video below.
The 3D printer turned out a tiny PC case, a monitor, and a joystick. The PC contains an ATtiny1614, an RGB LED, and some fiber optic to look like case lighting. The monitor is really a little OLED screen. A 5-way switch turns into the joystick.
[Mark Rehorst] has been busy designing and building 3D printers, and Son of Megamax — one of his earlier builds — needed a bed heater replacement. He took the opportunity to add a Kelvin-type kinematic mount as well. The kinematic mount and base efficiently constrain the bed in a controlled way while allowing for thermal expansion, providing a stable platform that also allows for removal and repeatable re-positioning.
After a short discussion regarding the heater replacement, [Mark] explains the design and manufacture of his kinematic mount. Of particular note are the practical considerations of the design; [Mark] aimed to use square aluminum tubing as much as possible, with machining requirements that were easily done with the equipment he had available. Time is a resource after all, and design decisions that help one get something working quickly have a value all their own.
If you’re still a bit foggy on kinematic mounts and how they work, you’re not alone. Check out our coverage of this 3D-printed kinematic camera mount which should make the concept a bit clearer.