That’s No Moon! That’s A Virtual Assistant

January 24, 2017 by Al Williams 8 Comments

[Wisecracker] likes how the Amazon Echo Dot works, but he doesn’t like how they sound or how they resemble hockey pucks. A little 3D printing, though, and he transformed the Dot into a credible Death Star. That doesn’t sound very friendly, we guess, so he calls it Alex-Star.

What makes it work is the Death Star’s “superlaser” — the weapon operated by a console that looks suspiciously like some studio video equipment — happens to be about the size and shape of a two-inch speaker. [Wisecracker] added a slot to let the sound out of the second speaker. You can see the thing in action in the video below.

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3D Printer Transforms To CNC

January 23, 2017 by Al Williams 26 Comments

Superficially, it is easy to think about converting a 3D printer into a CNC machine. After all, they both do essentially the same thing. They move a tool around in three dimensions. Reducing this to practice, however, is a problem. A CNC tool probably weighs more than a typical hotend. In addition, cutting into solid material generates a lot of torque.

[Thomas Sanladerer] knew all this, but wanted to try a conversion anyway. He had a few printers to pick from, and he chose a very sturdy MendelMax 3. He wasn’t sure he’d wind up with a practical machine, but he wanted to do it for the educational value, at least. The result, as you can see in the video below, exceeded his expectations.

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Stuff An Android In Your Xbox Controller’s Memory Slot

January 22, 2017 by Lewin Day 5 Comments

What is this, 2009? Let’s face facts though – smartphones are computing powerhouses now, but gaming on them is still generally awful. It doesn’t matter if you’ve got the horsepower to emulate any system from the last millennium when your control scheme involves awkwardly pawing away at glass when what you need is real buttons. You need a real controller, and [silver] has the answer – a 3D printed phone mount for the original Xbox Controller.

It’s more useful than it initially sounds. The original Xbox used USB 1.1 for its controllers. With a simple OTG cable, the controllers can be used with a modern smartphone for gaming. The simple 3D printed clamp means you can have a mobile gaming setup for pennies – old controllers are going cheap and it’s only a couple of dollars worth of filament. The trick is using the controller’s hilariously oversized memory card slots – for some reason, Microsoft thought it’d be fun to repackage a 64MB flash drive into the biggest possible form factor they could get away with. The slots also acted as a port for online chat headsets, and finally in 2017, we’ve got another use for the form factor.

For the real die-hard purists, [silver] also shares a photo of a similar setup with a Nintendo 64 controller – including a big fat USB controller adapter for it, hanging off the back. Not quite as tidy, that one.

It’s a neat little project – we love to see useful stuff built with 3D printers. If you’ve been looking for something functional to print, this is it. Or perhaps you’d like to try these servo-automated 3D printed light switches?

Multiextrusion 3D Printing And OpenSCAD

January 20, 2017 by Al Williams No comments

In a recent posting called Liar’s 3D Printing, I showed you how you can print with multiple filament colors even if your printer only has one extruder and hot end. It isn’t easy, though, and a lot of models you’ll find on sites like Thingiverse are way too complicated to give good results. An object with 800 layers, each with two colors is going to take a lot of filament changes and only the most patient among us will tolerate that.

What that means is you are likely to want to make your own models. The question is, how? The answer is, of course, lots of different ways. I’m going to cover how I did the two models I showed last time using OpenSCAD (seen below). The software is actually really well suited for this hack, making it easy for me to create a framework of several models to represent the different colors.

About OpenSCAD

I’m not going to say much about OpenSCAD. It is less a CAD package and more a programming language that lets you create shapes. We’ve covered it before although it changes from time to time so you might be better off reading the official manual.

The general idea, though, is you use modules to create primitives. You can rotate them and translate them (that is, move them). You can also join them (union) and take the difference of them (difference). That last is especially important. For example, look at the callsign plate above. Forget the text for now. See the two holes? Here’s the OpenSCAD that creates that shape:

 difference() {
 cube([basew,basel,basez]);
 // cut holes
 translate([4,basel/2,0]) cylinder(r=2,h=basez+2);
 translate([basew-4,basel/2,0]) cylinder(r=2,h= basez+2);
 }

The cube “call” creates the base. The cylinders are the holes and the difference “call” is what makes them holes instead of solid cylinders (the first thing is the solid and everything after is taken away). One key point: instead of numbers, the whole thing uses (mostly) variables. That means if you change the size of something, everything will adjust accordingly if you wrote the script well. Let’s look at applying these techniques for multiple colors.

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3D Printer With Tilted Bed

January 19, 2017 by Pedro Umbelino 37 Comments

[Oliver Tolar] and [Denis Herrmann], two students from the Zurich University of Applied Sciences (ZHAW), designed and produced a 3D printer prototype that has a movable printing bed that can tilt. By tilting, objects with critical overhangs can be printed without the additional support material. The printer has six axes, three axes control the print head as usual and three other axes control the printing bed, allowing a wider range of movements.

The students claim that besides saving on the support material this printer can actually save time while printing objects that need a lot of support since, we assume, it’s faster to tilt the bed than to print the support itself. In normal 3D printers the plate is always horizontal and the print object is built up in horizontal layers. In this printer, for large overhangs, the printing bed is held in such a way that the print object is pivoted until perpendicular to the print head. Of course, for round shapes it will probably be different but we only saw it in action in one demonstration video. There is also the plus side that, when a print finishes, it’s finished. No x-acto knife to remove support, no sand paper, no time wasted.

Having the software controlling the bed properly was more difficult than the assembly of the printer, they said. It is still under development as it cannot, for example, simultaneously move the print head and printing bed to produce a continuous print.

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Print Flexible PCBs With A 3D Printer

January 19, 2017 by Al Williams 21 Comments

Let’s get it out of the way right up front: you still need to etch the boards. However, [Mikey77] found that flexible plastic (Ninjaflex) will adhere to a bare copper board if the initial layer height is set just right. By printing on a thin piece of copper or conductive fabric, a resist layer forms. After that, it is just simple etching to create a PCB. [Mikey77] used ferric chloride, but other etchants ought to work, as well.

Sound simple, but as usual, the devil is in the details. [Mikey77] found that for some reason white Ninjaflex stuck best. The PCB has to be stuck totally flat to the bed, and he uses spray adhesive to do that. Just printing with flexible filament can be a challenge. You need a totally constrained filament path, for one thing.

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3D-Printed Strain Wave Gear Needs Your Help

January 17, 2017 by Dan Maloney 22 Comments

In most mechanical systems, metal gears that bend are a bad thing. But not so for strain wave gearing, which is designed to take advantage of a metal gear flexing to achieve an action much like planetary gears. The fun isn’t limited to metal anymore, though, if you 3D print a strain wave gear like this.

Strain-wave gearing is nothing new – it was invented in 1957 and has traveled to the moon on the lunar rover. And you may recall [Kristine Panos]’ recent article on a LEGO strain wave gear, which makes it easy to visualize how they work. She also has a great description of how the flex spline, wave generator, and circular spline interact, so we’ll spare those details here. [Simon Merret]’s interpretation of the strain wave gear is very simple and similar to other 3D-printed versions, except that he uses an inside-out timing belt as the flex spline. The wave generator is just an arm with a roller bearing at each end, and despite needing a few tweaks the gear does an admirable job.

Simon is reaching out for help in getting this gear ready for use where the industrial versions see frequent application – the first and second degrees of freedom of robotic arms. If you’ve got any ideas, head over to his project page on Hackaday.io and pitch in.

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