three_001.jpgOne of my many Lego NXT project ideas is to build a Rocker-Bogie system similar to the Mars Sojourner, Spirit and Opportunity rovers. It turns out a similar mechanism is ipresented by Brian Bagnall in his book titled Maximum Lego NXT: Building Robots with Java Brains.

While I wait on that book to move from my Amazon wish list, to my shipping list, I found a few interesting videos:

And a site by Kevin Knuth where the rocker bogie suspension has already been built. Kevin’s site has a few more video examples.

Here is an idea I have been playing with for a little while. Instead of simply doing a car with regular steering, I wanted to try a split chassis design where the front of the car rotates in the direction you want to turn. Here are two attempts, but I abandoned any further design after driving both around with my phone via bluetooth. The steering is too inaccurate to use for an autonomous robot, but it is fun to drive.

The other night I was researching building a balancing Segway like robot with the Lego Mindstorms NXT kit. I wanted a robot that could balance on two wheels and could move forward and backward. I also wanted the robot to recover when “pushed”.

I was familiar with Steve Hassenplug’s Legway built on the Lego RCX platform, but I wanted to tackle the challenge with the NXT. Luckily, I found Philo Hurbain’s NXTWay. I was intrigued enough to build a copy and try out the programming.

It is quite hard to get the balance right and in the end I created a very aggressive robot that I can push around and it will mostly right itself. Here is the video of the final creation.

I have been working on a few different designs for a holonomic drive robot. A true platform like the other killough platforms made from Lego would probably contain wheels that rotate differently, but I wanted to publish this design because it is interesting.

I tried two different versions that you can see in the movie below. One version uses wheels but I also built this platform into a three legged walker.

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My NXT arrived today so with the help of the kids, we build the first level robot and had some fun with programming. So far it is a better experience than my first hours with the original Mindstorms RCX (spent several hours on the phone with tech support). Building the first robot took about 20 minutes, including unwrap time with the help of twelve, five and four year old girls.


Click the picture for some quick pictures, including the new slimline turntables that I wish I could purchase in a 10 pack. More pictures will be posted to that gallery as we build through the different robots.

Of course, I shot a few simple videos: