Robotis has just announced a new line of Dynamixel Servos: the MX-series, beginning with the release of the MX-28.  The MX-28 servo has some distinct improvements over its RX-28 brethren: 12-bit (0.088°) angular resolution (four times that of the RX), full 360° controlled rotation (rather than 300°), non-contact magnetic encoders (not subject to mechanical wear), etc. -- and all for about the same price (MX-28: $219.90 MSRP, RX-28: $200)!   Of note, the MX-28 is prominently featured as part of the new DARwin-OP humanoid -- the recent Nao competitor that Robotis created in collaboration with Virginia Tech's RoMeLa Lab.  Perhaps best of all... Hizook was selected as a beta tester for this new servo (probably owing to our  prominent coverage of the RX-series and our awesome cross-platform open-source Robotis software library).  We were impressed with the new MX-28 -- read on for details, including an exclusive look inside the new servo as well as a quick tutorial using the updated open-source drivers (in python, complete with ROS bindings).  

I finally took a few minutes to watch a tear-down of the Roomba 4000 Series vacuum cleaner by Dino Segovis of DinoFab.com.  The 20-minute two-part video (embedded below) provides a pretty solid look at the design considerations that went into making the Roomba both robust and low-cost.  While the sensors and motherboard are definitely interesting, the motors are the most intriguing to me -- they seem to be separately fabricated modules with a small DC motor coupled to a planetary gearhead via a belt drive.   It is also striking just how much gunk (hair, dust, etc.) builds up inside every nook and cranny of the robot.  Definitely a hacker-friendly robot that offers plenty of lessons to people interested in designing commercial robots -- almost worth buying one just to look at first-hand.

Professional and hobbyist roboticists alike are snapping up Robotis Dynamixel Servos.  These "smart" servos serve an important niche between $30 hobby servos and super-expensive harmonic drive servos.  They sport torques ranging from 12 kg·cm to 106 kg·cm, and even more when doubled-up.  Most of my experience is with the RX-28 and RX-64 variants, which have 300° swing, 10-bit position sensing resolution, (roughly) 8-bit position control, force/torque sensing, available compliance mode, and can daisy-chain more than 250 servos.  At Georgia Tech's Healthcare Robotics Lab, we use dozens of these servos.  I recently invested a decent amount of time overhauling our open-source (Python) control software, adding (among other things) thread-safe operation and ROS (Robot Operating System) compatibility.  In this post, I'll do a brief overview of the Robotis Dynamixel offerings, look at a number of impressive applications where they are utilized, share pictures of a servo's disassembly, and give a brief tutorial using the new (awesome) open-source software libraries.