The trials of working with brushless DC motors for the first time.

We’ve all worked with DC motors at some point. Even if you aren’t a big hardware person, you’ve probably at least picked up a motor as a kid and touched a battery to the leads causing it to whir to life. These are usually standard DC motors and not their brushless relatives. Brushless motors require a bit more work since you are manually controlling things that are normally taken care of with the brushes. This article won’t teach you how, rather it will show you the mistakes one person made in his inaugural effort to use them. It is mildly amusing, but the project summary that he’s using them for seems even more interesting.

The job that’s been paying my bills and keeping me away from artsy-fartsy circuits for the past six months involves making a set of these enormous robot doors for a Certain Very Fancy Person’s house. Each door is 13 feet tall, around 7 feet wide, and weighs 1500 pounds. There are 66 of them in said house, and more in the servant quarters(!?!). The circuits on board each door have to handle running an onboard air compressor (which regulates a pneumatic weatherseal) as well as keeping track of temperature to linearize the pressure sensors when the weather gets cold. They also have to charge and maintain sealed lead acid batteries. They have commutated power rails. They have to communicate over said power rails, and do so using an capacitively-coupled data slicer and a proprietary protocol I wrote. This protocol has to be robust enough to bootload the processor over. It’s a proper embedded systems job.

Wow.

[via Adafruit]

Introduction to the H-bridge motor controller

[Chris] sent us this fantastic tutorial, introducing beginners to H-bridge motor drivers. While many of you will consider this stuff basic, those who are trying to expand from building only things the arduino board can handle to bigger more expansive (and powerful) projects will find this quite helpful.  [Chris's] tutorial is very in depth, not only going through the construction of the basic circuit but also showing you how to make your own PCB.  Pop on over there and learn some theory and some practice. Then you can build that battle bot you’ve always been dreaming of!

Wear a helmet, rollerblades with attitude

Wireless controller, more powerful custom-made motors, stronger frame, and with a name like DeathBlades, we can’t think of a single reason why you would prefer heel treads, well everyone was young at one time.

[Charleg] has been testing out a slightly new frame, despite having only half the motors necessary, and is getting great results hitting around 23Wh/mi. If you’re looking to build your own, his blog has a post for nearly every aspect of the design.

[Thanks Jerome Demers]

Marvelous Magnetic Machines

[HP Friedrichs] wrote in to tell us about an upcoming book titled Marvelous Magnetic Machines. Ordinarily, we skip over promotional hype. After watching his promo video though, we couldn’t help but share. We want a copy of this book. In this book you’ll find details on how to build a number of different motors from scrap. You can see several variations in the promo video. He also notes that the music was created by himself and some friends a few years ago. If [H.P. Friedrichs] sounds familiar, it is because he’s been sending us fantastic projects since at least 2006.

R/C airplane motors from computer trash

Here’s something that the R/C airplane crowd might think of as old news.  These directions show us how to rework floppy drive and CD Rom motors to be high power airplane motors.  There are several listed, with details on each, but those unfamiliar might want to start with the most basic CD Rom version. It covers winding your own copper and installing the magnets in the “bell”, putting it all together and mounting it. This is a great writeup for those who haven’t seen this done before. If you want something even simpler though, you might enjoy the homopolar motor post. If you’re more advanced, they have tips for you too on machining and balancing the motors as well as winding density.

Steven Laurie’s Art of the Motor


We’ve served up dozens if not hundreds of machines with a practical purpose, but we are always interested in machines like those [Steven Laurie] makes, which serve no other purpose than looking impressive, spewing smoke, leaving tire marks, and making a lot of racket. We’ll give you the scoop on Steve’s motor art after the break.

[Read more...]

Follow

Get every new post delivered to your Inbox.

Join 93,753 other followers