Let’s build a robot that gets hot. Really hot — like three times hotter than McDonald’s coffee. Then make it move around. And let’s get the cost in at around $100. Sounds crazy? Not really, since that describes the cheap 3D printers we all have been buying. [John] found out the hard way that you really need to be careful with hot moving parts.
The short story is that [John’s] Anet A8 caught on fire — significantly caught on fire. Common wisdom says that cheap printers often don’t have connectors for the heated bed that can handle the current. There have been several well-publicized cases of those connectors melting, especially on early production models of several printers. However, this printer had an add-on heater with a relay, so that shouldn’t be the problem. Of course, a cheap power supply could do it, too, but the evidence pointed to it being none of those things.
Moiré patterns are a thing of art, physics, and now tool design! [Julldozer] from Mojoptix creatively uses a moiré pattern to achieve a 0.05 mm precision goal for his custom designed 3D printed calipers. His calipers are designed to validate a 3D print against the original 3D model. When choosing which calipers are best for a job, he points out two critical features to measure them up against, accuracy and precision which he explains the definition of in his informative video. The accuracy and precision values he sets as constraints for his own design are 0.5 mm and 0.05 mm respectively.
By experimenting with different parameters of a moiré pattern: the scale of one pattern in relation to the other, the distance of the black lines on both images, and the thickness of black and white lines. [Julldozer] discovers that the latter is the best way to amplify and translate a small linear movement to a standout visual for measurement. Using a Python script which he makes available, he generates images for the moiré pattern by increasing line thickness ratios 50:50 to 95:5, black to white creating triangular moiré fringes that point to 1/100th of a millimeter. The centimeter and millimeter measurements are indicated by a traditional ruler layout.
It is funny how we always seem to pay the same for a new computer. The price stays the same, but the power of the computer is better each time. It would appear 3D printers may be the same story. After all, it wasn’t long ago that sinking a thousand bucks or more on a 3D printer wouldn’t raise any eyebrows. Yet today you can better printers for a fraction of that and $1,300 will buy you an open source Moai SLA printer as a kit. [3D Printing Nerd] took a field trip to MatterHackers to check the machine out and you can see the results in the video below.
The printer uses a 150 mW laser to make parts up to 130 mm by 130 mm by 180 mm. The laser spot size is 70 micron (compare that to the typical 400 micron tip on a conventional printer). The prints require an alcohol bath after they are done followed by a UV curing step that takes a few hours.
The invention of the relatively affordable 3D printer for home use has helped bring methods used to produce parts for prototypes, samples, and even manufacturing, closer to designers. This tutorial on how to cast metal parts from 3D printed silicone molds is a perfect example of how useful a 3D printer can be when you are looking to make a custom and durable metal part at home.
After 3D printing a mold design using an Ultimaker 2 [Matt Borgatti] casts the mold using Smooth-On Mold Star 15 that can withstand heat up to 450 °F (232 °C), which he points out is ideal for the low-temp metal casting alloy tin-bismuth comprised of 58% Bismuth and 42% Tin with a melting point of 281 °F.
You may have heard of molds created from 3D printed parts before, but what makes this tutorial great is that the author, [Matt Borgatti], really sets you up to be successful. He offers up plenty of insights including mold-making techniques and terminology like why you would need a well and runners designed as part of your mold when casting with metal.
You can either reproduce his designs or use the tutorial to create your own which makes it a good start for beginners as well as another method to file away for people who already have experience 3D printing molds. This post is also really a twofer. Not only do you get detailed instructions for the method but [Matt Borgatti] uses his casted metal part for a flat-packcamera arm he designed to document projects with which you can also build using his files found on Thingiverse.
To create molds for precision parts and to learn more about using a 3D printer as a tool in the casting process, check out this method for creating higher resolution molds with a resin printer.
[Ondřej Vocílka] is a student at the Brno University of Technology in the Czech Republic. In addition, the 23-year-old lost his vision in his left eye. While attending a lecture on 3D printing, he wondered if he could 3D print an ophthalmic prosthesis — an artificial eye. Turns out, he could. If you don’t speak Czech, you’ll need to call on a translation service like we did.
Unlike conventional glass or plastic eyes, it is trivial to change parameters like color when 3D printing the prosthetic. This is especially important with the iris and the finished product takes about 90 minutes to print. There is additional time required to coat the product with an acrylic layer to mimic the gloss of a natural eye.
3D Printing is often heralded as a completely new fabrication method, creating things that simply cannot be manufactured in other ways. While this is true, the widest reaching usefulness of 3D printers isn’t for pushing the limits of fabrication. The real power is in pushing the limits of manufacturing for individuals who need one-off parts.
The proof point is in the story shown above. A missing key on a keyboard could have meant an otherwise fine piece of hardware headed for recycling, but was saved by a single part printed on a desktop 3D printer. Multiply this by the increasing number of people who have access to these printers and you can see how using 3D printing for repairs will have a huge impact on keeping our gear in service longer.
We want to see how you’ve saved things from the rubbish pile. Show them off in Hackaday’s Repairs You Can Print contest. The best Student entry and the best Organization entry (think Hackerspace) will each win a high-end 3D Printer. But anyone can enter, with the top twenty entries receiving $100 credit for Tindie.
If you’re like us though, these prizes are just icing on the cake. The real reward is showing what some think is mundane but the Hackaday crowd believes is worth celebrating. Check out all the entries so far and join us below for a few highlights.
There has been a lot of activity from [Richard Horne] regarding 3D printing filaments lately; most recently he has shared two useful designs for upping one’s filament storage and monitoring game. The first is for a DIY Heated DryBox for 3D printing filament. It keeps filament dry not just by sealing it into a plastic box with some desiccant, but by incorporating a mild and economical heater intended for reptile habitats inside. Desiccant is great, but a gently heated enclosure can do wonders for driving away humidity in the right environment. The DryBox design also incorporates a handy little temperature and humidity sensor to show how well things are working.
The second design is a simple spin-off that we particularly liked: a 3D printed adapter that provides a way to conveniently mount one of the simple temperature and humidity sensors to a filament spool with a desiccant packet. This allows storing a filament spool in a clear plastic bag as usual, but provides a tidy way to monitor the conditions inside the bag at a glance. The designs for everything are on Thingiverse along with the parts for the Heated DryBox itself.
[Richard] kindly shares the magic words to search for on eBay for those seeking the build’s inexpensive key components: “15*28CM Adjustable Temperature Reptile Heating Heater Mat” and “Mini LCD Celsius Digital Thermometer Hygrometer Temperature Humidity Meter Gauge”. There are many vendors selling what are essentially the same parts with minor variations.
Since the DryBox is for dispensing filament as well as storing it, a good spool mounting system is necessary but [Richard] found that the lack of spool standardization made designing a reliable system difficult. He noted that having spool edges roll on bearings is a pretty good solution, but only if one doesn’t intend to use cardboard-sided spools, otherwise it creates troublesome cardboard fluff. In the end, [Richard] went with a fixed stand and 3D printable adapters for the spools themselves. He explains it all in the video, embedded below.