On a recent visit to London my son and I were fascinated by a tapping fingers automaton in the window of a shop. We thought it would be good to try and recreate the mechanism when we got home. We've been wanting to do more LEGO Technic building since my older son built the awesome Sisyphus kinectic sculpture from JKBrickworks.
Hand Automaton Inspiration
We took a video of the automaton in action so we could study its movement. This model was created by Nik Ramage as is based on a cast of his own hands, it's commercially available from Laikingland who make awesome kinetic sculptures.
It's a classic camshaft mechanism with four cams around a shaft. Camshafts are commonly used in engines to turn valves on an off with precise timing. It's a useful technique to learn.
LEGO Technic Version
In LEGO Technic we don't have much choice about the positioning of the cams so we placed them sequentially at 90 degrees to each other. This means that we'll have a continuous, equally spaced motion rather than the tapping and then rest of the Laikingland model.
Next we needed to create the fingers for the cams to tap. There are some LEGO Technic pieces that look just like fingers so we mounted four of those on another shaft with spacers.
Edison Robot Powered
We could just have turned the shaft with a handle, but we thought it would be more fun to control them with a motor like the automaton we had seen.
We've been trying out the Edison mini robot and it looked perfect for this job. The wheels on the Edison robot can be removed so that you can insert a LEGO Technic shaft. Perfect.
The Edison allows you to attach LEGO under its body so we built it up onto a platform. There are other Technic-compatible attachment points on the body of Edison so my older son was able to quickly come up with a way to mount the 'hand' securely.
The default speed of the motors is too fast for turning the shaft and made the fingers fly up into the air! So we added some programming to slow the motor down (it stops when you press the circle button.)
It's not as stylish as the original! But we were really pleased with the result.
Edison is looking like a fab little robot for making LEGO contraptions. It can detect obstacles and claps and has light sensors so there's lots of scope for creating interactive robots.
We have LEGO Power Functions, but that doesn't give you as much capability. We also have LEGO Mindstorms, but my older son is rather attached to his Fenrir wolf-bot and wasn't going to sacrifice it for this project!
Edison is a fab addition to my kids LEGO Technic making. We'd definitely recommend this robot for kids who have a big LEGO collection to encourage them to get the most from it. The compact size means that it's at the right scale for their everyday creations.
Edison have two books that explain how to make an awesome digger and drawing machine which each use two Edison robots plus the LEGO Technic 42032: Compact Tracked Loader set. The LEGO Edison model instructions are available free.