More Layoffs At MakerBot

February 16, 2017 by 43 Comments

MakerBot CEO [Nadav Goshen] announced that changes are needed to ensure product innovation and support long-term goals in a blog post published yesterday. To that end, MakerBot will reduce its staff by 30%. This follows a series of layoffs over a year ago that reduced the MakerBot workforce by 36%. With this latest series of layoffs, MakerBot has cut its workforce by over 50% in the span of two years.

In addition to these layoffs, the hardware and software teams will be combined. Interestingly, the current Director of Digital Products, [Lucas Levin], will be promoted to VP of Product. Many in the 3D printer community have speculated MakerBot is pivoting from a hardware company to a software company. [Levin]’s promotion could be the first sign of this transition.

When discussing MakerBot, many will cite the documentary Print the Legend. While it is a good introduction to the beginnings of the desktop 3D printer industry, it is by no means complete. The documentary came out too early, it really doesn’t mention the un-open sourceness of MakerBot, the lawsuit with Form Labs wasn’t covered, and there wasn’t a word on how literally every other 3D printer manufacturer is selling more printers than MakerBot right now.

Is this the end of MakerBot? No, but SYSS is back to the pre-3D-printer-hype levels. Stratasys’ yearly financial report should be out in a month or so. Last year, that report was the inspiration for the MakerBot obituary. It’s still relevant, and proving to be more and more correct, at least from where MakerBot’s Hardware business stands.

Hands On With Variable Layer Height

February 16, 2017 by 33 Comments

3D printers are an exercise in compromise. Generally, you don’t want a lot of mass on your tool head, as that can lead to ringing and other mechanical artifacts on your print. However, direct drive extruders are better for many filaments, and the decision on what printer to build ultimately comes down to a choice between speed, build area, and the ability to print in exotic filaments.

Even in slicing a 3D model, a 3D printing enthusiast must balance the quality of a print versus how long the print will take to squirt out of a nozzle. Now, just about any printer can produce fantastic models at a very high layer height, but no one wants to wait several days for the print to finish.

This balance between print time and print quality has, for the last few years, been completely ignored. One of the best solutions to this we’ve seen is variable layer height slicing. Basically, if you’re printing something without much detail, you don’t need small layers in your 3D print. Think of it as printing the neck of a bust at 0.3mm layer height, and the face at 0.1mm.

Yes, there were a few papers from a decade ago laying the conceptual foundations of variable layer height slicing. 3D printers weren’t exactly common back then, though. Recently, Autodesk’s Integrated Additive Manufacturing Team released Varislice for automatic generation of variable layer heights on a 3D printed object. So far, though, there’s no good automated solution for variable layer height slicing, and the tools for manual configuration of variable layer height slicing are terrible.

For the past few months, Prusa Research has been working on their own edition of Slic3r that includes an easy to use interface for variable layer height slicing. This version of Slic3r was just released, and now it’s time for the hands-on. Does variable layer height slicing work?

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Building Homebrew VTOL Rockets

February 16, 2017 by 35 Comments

No one can deny what SpaceX and Blue Origin are doing is a feat of technological wizardry. Building a rocket that takes off vertically, goes into space, and lands back on the pad is an astonishing technical achievement that is literally rocket science. However, both SpaceX and Blue Origin have a few things going for them. They have money, first of all. They’re building big rockets, so there’s a nice mass to thrust cube law efficiency bump. They’re using liquid fueled engines that can be throttled.

[Joe Barnard] isn’t working with the same constraints SpaceX and Blue Origin have. He’s still building a rocket that can take off and land vertically, but he’s doing it the hard way. He’s building VTOL model rockets. Most of the parts are 3D printed. And he’s using solid motors you can buy at a hobby shop. This is the hard way of doing things, and [Joe] is seeing some limited success with his designs.

While the rockets coming out of Barnard Propulsion Systems look like models of SpaceX’s test vehicles, there’s a lot more here than looks. [Joe] is using a thrust vectoring system — basically mounting the Estes motor in a gimbal attached to a pair of servos. This allows the rockets to fly straight up without fins or even the launch rod used to get the rocket up to speed in the first few millseconds of flight. This is active stabilization of a model rocket, with the inevitable comments of ITAR violations following soon afterward.

Taking off vertically is one thing, but [Joe] is also trying to land his rockets vertically. Each rocket he’s built has a second Estes motor used only for landing. During descent, the onboard microcontroller calculates the speed, altitude, and determines if it’s safe to attempt a vertical landing. If the second motor has sufficient impulse to make velocity and altitude equal zero at the same time, the landing legs deploy and the rocket hopefully makes a soft touchdown in the grass.

While [Joe] hasn’t quite managed to pull off a vertical takeoff and landing with black powder motors quite yet, he’s documenting and livestreaming all of his attempts. You can check out the latest one from a week ago below.

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How A Van De Graaff Generator Works

February 16, 2017 by 42 Comments

What I particularly like about the Van de Graaff (or VDG) is that it’s a combination of a few discrete scientific principles and some mechanically produced current, making it an interesting study. For example, did you know that its voltage is limited mostly by the diameter and curvature of the dome? That’s why a handheld one is harmless but you want to avoid getting zapped by one with a 15″ diameter dome. What follows is a journey through the workings of this interesting high voltage generator.

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Does This Demo Remind You Of Mario Kart? It Should!

February 16, 2017 by 13 Comments

Here’s a slick-looking VGA demo written in assembly by [Yianni Kostaris]; it’s VGA output from an otherwise stock ATmega2560 at 16MHz with no external chips involved. If you’re getting some Super Mario Kart vibes from how it looks, there’s a good reason for that. The demo implements a form of the Super Nintendo’s Mode 7 graphics, which allowed for a background to be efficiently texture-mapped, rotated, and scaled for a 3D effect. It was used in racing games (such as Super Mario Kart) but also in many others. A video of the demo is embedded below.

[Yianni] posted the original demo a year earlier, but just recently added detailed technical information on how it was all accomplished. The AVR outputs VGA signals directly, resulting in 100×120 resolution with 256 colors, zipping along at 60 fps. The AVR itself is not modified or overclocked in any way — it runs at an entirely normal 16MHz and spends 93% of its time handling interrupts. Despite sharing details for how this is done, [Yianni] hasn’t released any code, but told us this demo is an offshoot from another project that is still in progress. It’s worth staying tuned because it’s clear [Yianni] knows his stuff.

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Teardown Of Nike Self-Lacing Shoes

February 16, 2017 by 51 Comments

There used to be a time, before running shoes had blinking LEDs and required placing on an inductive charger overnight, when we weren’t worried about whether or not we could dump the firmware running underneath our heels. Those are not the times that we’re living in. Nike came out with a shoe that solves the age-old problem of lacing: the HyperAdapt. And [Telind Bench] has torn them apart.

img_0059Honestly, we’re kinda “meh” about what’s inside. The “laces” are actually tubes with a small Kevlar-like cable running inside, and the whole thing torques up using a small, geared DC motor. That’s kinda cool. (We have real doubts about [Telind]’s guess of 36,000 RPM for the motor speed.) But in an age when Amazon gives away small WiFi-enabled devices for a few bucks as a loss-leader to get you to order a particular brand of laundry detergent, we’re not so dazzled by the technology here, especially not at the price of $720 for a pair of freaking shoes.

The only really interesting bit is the microcontroller, which is over-powered for the job of turning a wheel when a keyboard-style sensor is pressed by your heel. What is Nike thinking? We want to see the firmware, and we’d like it reverse engineered. What other chips are on board? Surely, they’ve got an accelerometer and are measuring your steps, probably tying in with an exercise app or something. Does anyone have more (technical) detail about these things? Want to make a name for yourself with a little stunt hacking?

LTSpice For Radio Amateurs (and Others)

February 15, 2017 by 16 Comments

We don’t think [VK4FFAB] did himself a favor by calling his seven-part LTSpice tutorial LTSpice for Radio Amateurs. Sure, the posts do focus on radio frequency analysis, but these days lots of people are involved in radio work that aren’t necessarily hams.

Either way, if you are interested in simulating RF amplifiers and filters, you ought to check these posts out. Of course, the first few cover simple things like voltage dividers just to get your feet wet. The final part even covers a double-balanced mixer with some transformers, so there’s quite a range of material.

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