Kicking The Tires Before You Buy: 3d Printers

So you’re looking to buy your first 3D printer, and your index finger is quivering over that 300 US Dollar printer on Amazon.com. Stop! You’re about to have a bad time. 3D printing has come a long way, but most 3D printers are designed through witchcraft, legends, and tall tales rather than any rigorous engineering process. I would say most 3D printer designs are either just plain bad, or designed by a team of Chinese engineers applying all their ingenuity to cost cutting. There are a few that are well designed, and there is a comparatively higher price tag attached.

I’ll start by going through some of the myths and legends that show up in 3D printers. After that I’ll go through some of the common, mostly gimmick, features that typically hinder your printer’s ability, rather than adding any useful function. Next I’ll go onto the things that will actually make your printer better. Finally, I’ll add some special consideration if you’re a beginner buying your first printer.

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Alfred P. Morgan: A Generation’s Radio Hacker

I was surfing the web looking for interesting projects the other day when I ran into [SkyKing’s] exquisite transistor demodulator radio builds. He mentioned that they were “Alfred P. Morgan-style” and that brought back a flood of memories about a man who introduced a whole generation to electronics and radio.

[Morgan] was born in 1889 and in the early part of the twentieth century, he was excited to build and fly an airplane. Apparently, there wasn’t a successful flight. However, he eventually succeeded and wrote his first book: “How to Build a 20-foot Bi-Plane Glider.” In 1910, he and a partner formed the Adams Morgan company to distribute radio construction kits. We probably wouldn’t remember [Morgan] for his airplanes, but we do recognize him for his work with radio.

By 1913, he published a book “The Boy Electrician” which covered the fundamentals of electricity and magnetism (at a time when these subjects were far more mysterious than they are today). [Morgan] predicted the hacker in the preface to the 1947 edition. After describing how a boy was frustrated that his model train automated to the point that he had nothing actually to do, [Morgan] observed:

The prime instinct of almost any boy at play is to make and to create. He will make things of such materials as he has at hand, and use the whole force of dream and fancy to create something out of nothing.

Of course, we know this applies to girls too, but [Morgan] wrote this in 1913, so you have to fill in the blanks. I think we can all identify with that sentiment, though.

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SAINTCON Badge (Badge Hacking for Mortals)

[Josh] attended his first SAINTCON this weekend before last and had a great time participating in the badge hacking challenge.

The 2014 SAINTCON is only the second time that the conference has been open to the public. They give out conference badges which are just an unpopulated circuit board. This makes a lot of sense if you figure the number of people who actually hack their badges at conferences is fairly low. So he headed off to the hardware hacking village to solder on the components by hand — it’s an Arduino clone.

This is merely the start of the puzzle. We really like that the published badge resources include a crash course on how to read a schematic. The faq also attests that the staff won’t solder it for you and to get your microcontroller you have to trade in your security screw (nice touch). Once up and running you need to pull up the terminal on the chip and solve the puzzles in the firmware’s menu system. This continues with added hardware for each round: an IR receiver, thermistor, EEPROM, great stuff if you’re new to microcontrollers.

[Josh] mentions that this is nothing compared to the DEFCON badge. Badge hacking at DEFCON is **HARD**; and that’s good. It’s in the top-tier of security conferences and people who start the badge-solving journey expect the challenge. But if you’re not ready for that level of puzzle, DEFCON does have other activities like Darknet. That is somewhere in the same ballpark as the SAINTCON badge — much more friendly to those just beginning to developing their crypto and hardware hacking prowess. After all, everyone’s a beginner at some point. If that’s you quit making excuses and dig into something fun like this!

A-Z of Electronics – Capacitors

a_to_z_electronics

[Jeri Ellsworth] recently released another video in her “A-Z of Electronics” series – this time Capacitors are the subject. As a penance for my boneheaded AC Capacitor suggestion yesterday (I swear it was lack of sleep talking), [Caleb] suggested that I be the one to write this article. Since I’m not an electrical engineer (I majored in Comp Sci), I enjoy watching these videos, and I share them with individuals who are new to electronics. [Jeri] always presents the subject matter in a clear and concise manner, so the subjects do not seem daunting or intimidating.

She briefly discusses the early development of capacitors, including Leyden Jars, then focuses on modern capacitors and their usage. She covers wiring capacitors in circuits, demonstrating the difference between series and parallel configurations, as well as how electrode distance affects capacitance.

If you have a spare minute, be sure to check out her current video as well as those she has previously released.

RGB “Tilty cube”

[Ben’s] introduction to microcontrollers was this fun little gift he calls the “tilty cube”. It is an acrylic box with 3 LEDs mounted inside that changes color based off of how you tilt it. Sounds like a fun toy, and a good project to learn with. [Ben] chose the PIC12F615 as the brains and laid it all out on a perfboard.  Since this was his first microcontroller experience he had to learn how to blink the LEDs, then figure out PWM etc. Though there is no video of the project in its finished state, since it was given away as a gift, we assume he figured it out pretty well.  He does state that the LEDs are dimmer than he had hoped and offers some thoughts on how he would do the entire project better next time.

Introductions: 3 new writers

We would like to introduce our new writers [Rachel Fee], [Greg Jacobs], and [Jacob Nahin]. They will be focusing on software reviews and tutorials in response to the daily requests for posts that don’t require that you be an electrical engineer to understand.

The Hack a Day community is growing very fast and we are happy to be a valued source of information to our readers.