I’ve been researching Robo-One style bipeds lately, so I know a bit about the options that are out there. Here is a quick little summary of them and a brief opinion:
Hitec Robonova-1: A lot of people have this, so there is a lot of information, code, mods, etc. However, the servos are underpowered compared to the competition, but there are new more powerful servos to upgrade it. People seem to like the software and the RoboBasic language. The gold anodized brackets are nice. Lynxmotion sells it, which is a bonus. Also, there is a ReadyToWalk version, which is perfect for beginners.
Kondo KHR-2HV/KHR-1HV: Similar price to the RoboNova (about $1000), but more powerful, and the user base seems to be accelerating. The plastic brackets look cheap. The Heart2Heart sequencing software pretty much sucks compared to the others, but it’s usable.
Kyosho Manoi AT01: Based on the KHR-1HV electronics, but with stronger molded composite brackets and a paintable polycarbonate shell. A sign of things to come. It also uses Heart2Heart. This one is not yet available in the US except to educators, but you can buy it from Japan for about $1600 shipped. This is the most expensive option, but it may be the kewlest.
Robotis Bioloid Comprehensive: Similar price to above (about $900), but much more powerful and sophisticated servos. Also, the software seems to be more polished. The downside with this one is that the gray plastic parts don’t really look that nice.
Lynxmotion Scout/Custom Servo Erector Set: Modular, affordable, upgradable and infinitely customizable. Nothing proprietary here, so you can do what you want, but it probably takes more skill to really get this one going. The SSC-32 and Lynxmotion Sequencer software are nice and very well supported. One downside here is that you need to stack two largish boards to get full servo control from the SSC-32/SEQ along with a microcontroller board (AtomBotBoard). Note: This is a non-issue in a Johnny5 build because you have the rover base for electronics.
HPI/Futaba GR-001: New robot, smaller than all the above, but very fast and agile. More expensive than all except maybe the Manoi. Also not yet available unless you order it from Japan. Looks pretty cool, but I can’t see paying more for a smaller biped unless you are a speed freak.
My personal feeling is that the Bioloid might be the best overall Robo-One option, especially for someone starting out. It has a Lego kind of quality to it, only much much nicer. The Robonova-1 is probably the best choice for a beginner that wants metal brackets and a real Robo-One look. I think the other options are all nice, but may be better for someone a little more advanced.
The Johnny5 is probably the way to go if you want it to be able to move around on carpet. How do you want to spend your time, trying to get it to walk without falling, or actually programming behavior?
Honestly, all of the above options are viable. It really depends on your skill level and what you like. I’d pick the one that gets your juices flowing and make it your own.
I’m not sure which direction I’ll end up going. I’m going to finish up a rover I’m working on then decide for sure. The cash is really burning a hole in my pocket though!