Fast 3D Printing With Raspberry Pi — But Not How You Think

December 26, 2017 by Al Williams 117 Comments

Although we tend to think of 3D printers as high-tech toys, most of them are not especially powerful in the brain department. There are some exceptions, but most 3D printers run on either an 8-bit Arduino or some Arduino variant with a lot of I/O. There are a few 32-bit boards, but if you grab a random 3D printer, its brain is going to be an 8-bit AVR running something like Marlin or Repetier. It isn’t uncommon to see a Raspberry Pi connected to a printer, too, but — again, in general — it is a network interface that handles sending G-code to the 8-bit controller that runs the stepper motors. Would it make more sense to do things like parse G-code, map out curves, and set accelerations in the relatively powerful Raspberry Pi and relegate the 8-bit AVR to just commanding motors and heaters? [KevinOConnor] thinks so, and he wrote Klipper to prove it.

Klipper is mostly written in Python and it does most of the functions of traditional 3D printing firmware. It communicates with the onboard microprocessor by providing a schedule of when to do what tasks. The microprocessor then handles the timing and things like motion control for the axes and extruder. Klipper can control multiple microprocessors with no trouble and keeps them in synchronization, so you could have a processor for your extruder and one for each stepper, for example. You can use Klipper with a Cartesian machine, a delta, or a Core XY-style printer.

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Coin Cells: The Mythical Milliamp-Hour

December 22, 2017 by Elliot Williams 16 Comments

Just how much metaphorical juice is in a coin cell battery? It turns out that this seemingly simple question is impossible to answer — at least without a lot of additional information. The problem is that the total usable energy in a battery depends on how you try to get that energy out, and that is especially true of coin cells.

For instance, ask any manufacturer of the common 3 V lithium 2032 batteries, and they’ll tell you that it’s got 230 mAh. That figure is essentially constant across brands and across individual cells, and if you pull a constant 0.2 mA from the battery, at room temperature and pressure, you’ll get a bit more than the expected 1,150 hours before it dips below the arbitrary voltage threshold of 2.0 V. Just as it says on the tin.

What if you want to do anything else with a coin cell? Run an LED for a decade? Pull all the energy out right now and attempt to start a car? We had these sorts of extreme antics in mind when we created the Coin Cell Challenge, but even if you just want to do something mundane like run a low-power radio sensor node for more than a day, you’re going to need to learn something about the way coin cells behave in the real world. And to do that, you’re going to need to get beyond the milliamp hour rating. Let’s see how deep this rabbit hole goes.

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Magic Leap Finally Announced; Remains Mysterious

December 21, 2017 by Mike Szczys 74 Comments

Yesterday Magic Leap announced that it will ship developer edition hardware in 2018. The company is best known for raising a lot of money. That’s only partially a joke, since the teased hardware has remained very mysterious and never been revealed, yet they have managed to raise nearly $2 billion through four rounds of funding (three of them raising more than $500 million each).

The announcement launched Magic Leap One — subtitled the Creator Edition — with a mailing list sign up for “designers, developers and creatives”. The gist is that the first round of hardware will be offered for sale to people who will write applications and create uses for the Magic Leap One.

We’ve gathered some info about the hardware, but we’ll certainly begin the guessing game on the specifics below. The one mystery that has been solved is how this technology is delivered: as a pair of goggles attaching to a dedicated processing unit. How does it stack up to current offerings?

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Taking A Guitar Pedal From Concept Into Production

December 20, 2017 by Zoe Skyforest 24 Comments

Starting a new project is fun, and often involves great times spent playing with breadboards and protoboards, and doing whatever it takes to get things working. It can often seem like a huge time investment just getting a project to that functional point. But what if you want to take it to the next level, and take your project from a prototype to a production-ready form? This is the story of how I achieved just that with the Grav-A distortion pedal.

Why build a pedal, anyway?

A long time ago, I found myself faced with a choice. With graduation looming on the horizon, I needed to decide what I was going to do with my life once my engineering degree was squared away. At the time, the idea of walking straight into a 9-5 wasn’t particularly attractive, and I felt like getting back into a band and playing shows again. However, I worried about the impact an extended break would have on my potential career. It was then that I came up with a solution. I would start my own electronics company, making products for musicians. Continue reading “Taking A Guitar Pedal From Concept Into Production” →

Prepping For Power Outages

December 19, 2017 by Jenny List 268 Comments

When the mains power goes, we are abruptly brought face-to-face with how many of the devices and services we take for granted rely upon it. Telephones for instance, where once they were attached to the wall by a cable, now they are a cordless device with a mains-powered base station. Your cellphone can fill that gap, but a modern smartphone with a battery life of under a day is hardly a reliable long-term solution. Meanwhile modern heating systems may still burn gas or fuel oil, but rely on an electric pump for circulation. Your kitchen is full of electrically-powered white goods, your food is preserved by an electric refrigerator, even your gas cooker if you have one will probably expect a mains supply.

When the power goes out we might say that we instantaneously travel back a couple of centuries, but the reality is that our ancestors in 1817 wouldn’t have been in the same mess we are, they had appropriate solutions to surviving a wickedly cold winter when electricity was still something of a gleam in [Michael Faraday]’s eye. In short, they were prepared in a way most of us are not. That’s a shame, so let’s take a closer look sensible modern preparedness.

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3D Printing The Final Frontier

December 18, 2017 by Tom Nardi 29 Comments

While down here there’s room for debate about the suitability of 3D printing for anything more serious than rapid prototyping, few would say the same once you’ve slipped the surly bonds of Earth. With 3D printing, astronauts would have the ability to produce objects and tools on-demand from a supply of inert raw building materials. Instead of trying to pack every conceivable spare part for a mission to Mars, replacements (assuming a little forward thinking on the part of the spacecraft designers) can be made to order out of the stock of raw plastic or metal kept on-board. The implications of such technology for deep space travel or off-world settlement simply cannot be overstated.

In the more immediate future, 3D printing can be used to rapidly develop and deploy unmanned spacecraft. Tiny satellites (referred to as CubeSats) could be printed, assembled, and deployed by astronauts already in orbit. Innovations such as these could allow science missions to be planned and executed in months instead of years, and at a vastly reduced cost.

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Hardware Heroes: Isambard Kingdom Brunel

December 15, 2017 by Jenny List 45 Comments

There are some notable figures in history that you know of for just one single thing. They may have achieved much in their lifetimes or they may have only been famous for Andy Warhol’s fifteen minutes, but through the lens of time we only know them for that single achievement. Then on the other hand there are those historic figures for whom there is such a choice of their achievements that have stood the test of time, that it is difficult to characterize them by a single one.

[Isambard Kingdom Brunel], in front of the launching chains for the Great Eastern. [Public domain] — Isambard Kingdom Brunel, in front of the launching chains for the *Great Eastern*. [Public domain]

Such is the case of Isambard Kingdom Brunel, the subject of today’s Hardware Heroes piece. Do we remember him for his involvement in the first successful tunnel to pass beneath a river, as a builder of some of the most impressive bridges on the 19th century, the innovator in all aspects of rail engineering, the man behind the first screw-driven ocean-going iron ship, or do we remember him as all of those and more?

It is possible that if you are not British, or in particular you are not from the West of England, this is the first you’ve heard of Brunel. In which case he is best described as a towering figure of many aspects of engineering over the middle years of the 19th century. His influence extended from civil engineering through the then-emerging rail industry, to shipbuilding and more, and his legacy lives on today in that many of his works are still with us.

Engineering: The Family Trade

Brunel’s father, Marc Brunel, was an engineer and refugee from the French Revolution who found success in providing the British Navy with a mass-production system for wooden pulley blocks as used in the rigging of sailing ships. He enters this story for his grand project, the world’s first tunnel to be dug under a navigable river, beneath London’s River Thames from Rotherhithe to Wapping, and for his patented tunneling shield which made it possible to be dug.

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