Archives for posts with tag: kiwi drive


Yesterday I published building instructions for a single leg of my holonomic robot Agilis. Here are the full instructions. These include the central frame and three sensor docks. Have fun with it.

Download the Building instructions




The large EV3 motor has a different form factor then the NXT motor. I had to redesign the legs of Agilis to make use of these new motors.


EV3HolonomicLeg2The new design is smaller and much prettier to the eye. The smaller size and all the triangular shapes makes the leg very stable. The new leg can be fitted on the same triangular frame that was used for Agilis.

Here are the building instructions for the new leg.

If you only have two large EV3 motors you can easily modify the leg to use the EV3 medium motor. This motor can be attached directly to the drive axis of the wheel and to the underside of the frame. You will have no gearing. But as the medium motor rotates a bit faster you will still have plenty of speed in your robot.

I got some feed-back on my last post with “building instructions” for Agilis. My friend Kirk wondered why I didn’t make proper instructions. He was not impressed by my lame excuses about odd angles or illegal builds and showed me things could be done. He was right, it was about time for me to master some Lego CAD tools. I choose to use LDraw¬†and MLCad for the job. My fears for a steep learning curve proved wrong. The manual is quite good and I was up and running within an hour. The hardest thing to learn was the discipline to work precise immediately. One cannot build a sketch at first and then improve the model. Well, technically you can, but you shouldn’t as every brick you move triggers a chain of new moves that need to be made.

It was fun to create proper building instructions for Agilis. Along the way I also improved the gearbox as was suggested by another reader of my blog, Thimoty. You can freely download the instructions. I do appreciate constructive feedback. This is my first and I am sure there is room for improvement.

Download the building instructions for Agilis

For my birthday I got the Rotacaster wheels, four of them!

They are nice! A bit smaller than I expected, but the size is perfect. It gave me some new challenges. I never built a triangular robot before.
Below are the first picturesof my triangular robot. For prototype I’m rather pleased with it, it is compact, lightweight and sturdy. The only real issue with the robot is that I cannot replace the batteries without removing the NXT from the chassis.

The robot features a US-sensor, giving it a face and a front side, a Mindsensors medium range distance sensor, a Hitechnic gyro sensor and a Mindsensors accelerometer. There is a Mindsensors sensor port splitter on the bottom of the robot that it is out of view. Currently only the gyro is functional, it helps the robot to keep its orientation.

There is not much programming done yet. The only new stuff I wrote thus far deals with driving. The robot can drive in any direction. It can spin around its vertical axis and it can orientate itself in a certain direction. It can do all off this at the same time. It is really funny to look at the robot performing some of the patterns that I used for testing.
I’m not sure what kind of behaviour I will give this robot. My son wants to control it with a joystick. So that might be the first thing to implement.

The robot does not have a name yet. Any suggestions?