Practical Enclosure Design, Optimized for 3D Printing

[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.

The road to enclosures has many paths, including enclosures made from FR4 (aka PCB material) all the way down to scrap wood with toner transfer labeling, and certainly desktop 3D printing has been a boon to anyone who’s had to joylessly drill and saw away at a featureless plastic box.

Josef Prusa: Multi Material Extruders for Amazing Color Prints

The Prusa i3 Mk 2 is the hotness in consumer-grade, quality 3D printing right now. And things just keep getting more interesting. We caught up with Josef Průša at Maker Faire Bay Area this weekend to see the multi-material extruder in its final form. It’s an upgrade to the Mk 2 which allows a single hot end to print in four different materials, be it different colors or different types of filament.

Continue reading “Josef Prusa: Multi Material Extruders for Amazing Color Prints”

Everything’s a Touch Surface with Electrick

Touch screens are great, but big touchscreens are expensive and irregular touchscreens are not easy to make at all. Electrik is a method developed by several researchers at Carnegie Mellon University that makes almost any solid object into a touch surface using tomography. The catch is that a conductive coating — in the form of conductive sheets, 3D plastic, or paint — is necessary. You can see a demonstration and many unique applications in the video below. They’ve even made a touch-sensitive brain out of Jell-O and a touchable snowman out of Play-Doh.

The concept is simple. Multiple electrodes surround the surface. The system injects a current using a pair of electrodes and then senses the output at the other terminals. A finger touch will change the output of several of the electrodes. Upon detection, the system will change the injection electrodes and repeat the sensing. By using multiple electrode pairs and tomography techniques, the system can determine the location of touch and even do rough motion tracking like a low-resolution touch pad mouse.

Continue reading “Everything’s a Touch Surface with Electrick”

Self-assembling Polymers Support Silicone 3D Prints

We all know what the ultimate goal of 3D printing is: to be able to print parts for everything, including our own bodies. To achieve that potential, we need better ways to print soft materials, and that means we need better ways to support prints while they’re in progress.

That’s the focus of an academic paper looking at printing silicone within oil-based microgels. Lead author [Christopher S. O’Bryan] and team from the Soft Matter Research Lab at the University of Florida Gainesville have developed a method using self-assembling polymers soaked in mineral oil as a matrix into which silicone elastomers can be printed. The technique takes advantage of granular microgels that are “jammed” into a solid despite being up to 95% solvent. Under stress, such as that exerted by the nozzle of a 3D printer, the solid unjams into a flowing liquid, allowing the printer to extrude silicone. The microgel instantly jams back into a solid again, supporting the silicone as it cures.

[O’Bryan] et al have used the technique to print a model trachea, a small manifold, and a pump with ball valves. There are Quicktime videos of the finished manifold and pump in action. While we’ve covered flexible printing options before, this technique is a step beyond and something we’re keen to see make it into the hobby printing market.

[LonC], thanks for the tip.

Monoprice Releases Their Mini Delta Printer (On Indiegogo)

Around this time last year, Monoprice quietly unveiled a small, $200 3D printer. At the time, a fully functioning printer at this price point wasn’t unheard of. A good 3D printer at this price point was. It turned out this printer was actually fantastic and completely changed the value proposition of desktop 3D printers.

In the year since the release of the MP Select Mini printer, Monoprice has been hard at work bringing costs down, reworking designs, and creating an even less expensive printer. Now, it’s out. It’s available for pre-order on Indiegogo right now. Is this still a $150 printer? Not quite: the ‘early bird’ price is $159 with free shipping and August delivery, and a regular price of $169 plus $10 shipping with September or October delivery. There’s also a bundle for $279 that includes the printer, 2kg of filament, and a software package.

The first time we saw this tiny printer was way back in January at CES. It looked to be an extremely capable printer; the only question was if Monoprice could produce it and get it out the door. This would be a tall order; this printer comes with NEMA 17 stepper motors, a heated bed, a 32-bit controller board, and has WiFi enabled.

Here’s what we know about the capabilities of this printer. It’s a fairly standard delta printer with Bowden extruder and a heated bed. PLA and ABS is supported. The printer has auto bed leveling that measures the bed by ‘tapping’ the nozzle against the bed in about a dozen places before printing. From what we saw at CES, the hot end appears similar to the first revision of the $200 MP Select Mini — possibly opening up the door to E3D hot end installations.

Is this printer worth it? Every 3D printer released on a crowdfunding platform should come with the standard warnings, but Monoprice says this machine is in production right now. This raises the question: why release it on Indiegogo when Monoprice already has the whole ‘taking orders for products online’ thing in the bag? I suspect this crowdfunding campaign is just building a buffer; a year ago, the MP Select Mini was perpetually out of stock, and demand far outstripped supply. The same thing will happen with a 3D printer that’s even deeper into impulse buy territory.

In any event, the printer we’ve all been waiting for has been ‘released’, for varying values of ‘released’. The first units will start making their way onto desktops this summer, and we’re going to pick one up and put it through its paces. You can check out Monoprice’s video of this printer below.

Continue reading “Monoprice Releases Their Mini Delta Printer (On Indiegogo)”

3D Printing Custom LED Bar Graphs

[BikerGlen] wanted to spice up his zombie containment unit (see video below) so he designed and 3D printed some very cool looking bar graphs. Apparently, you can get curved bar graph LEDs, but only if you buy a fairly large quantity. Hand soldering discrete LEDs at the perfect angle would be frustrating, but with a 3D printed jig, it was a piece of cake.

The devices use a MAX6954 LED driver, so it needs very few parts and takes commands via SPI. The chips were not cheap, but the small size and high integration sold [Glen] on it.

Continue reading “3D Printing Custom LED Bar Graphs”

Transparent 3D Printing?

Transparent plastic is nothing new. However, 3D prints are usually opaque or–at best–translucent. [Thomas Sanladerer] wanted to print something really transparent. He noticed that Colorfabb had an article about printing transparent pieces with their HT filament. [Thomas] wanted to try doing the same thing with standard (and cheaper) PETG, which is chemically similar to the HT. Did he succeed? Watch the video below and find out.

You can get lots of clear plastic filament, but the process of printing layers makes the transparency turn cloudy, apparently mostly due to the small gaps between the layers. The idea with the HT filament is to overextrude at a high enough temperature that the layers can fuse together.

[Thomas] wanted to create some clear parts and diffusers for lamps. The diffusers print using vase mode and the lamps he creates when them look great even without clear diffusers.

His first experiments involved layer height and extrusion rates. He tried to determine what was making things better and worse and modifying his technique based on that. There were also some post-processing steps he tried.

If you want to see what the Colorfabb HT parts made by someone other than Colorfabb look like, check out the second video below from [3D Printing Professor]. The prints he is making don’t look very clear until he does some post processing. Even after the post processing, it isn’t going to fool anyone into thinking it is glass-clear. However, the parts that Colorfabb shows on their blog post about the material do look amazing. Between the overextrusion used to prevent gaps and the post processing steps, [3D Printing Professor] warns that it won’t be easy to get parts with precise dimensions using this technique.

If you have a big budget, you could try printing with actual glass. There seem to be several ways to do that.