Lego Mindstorms EV3 Rubik’s Cube Solver

This has been around for a while now. We didnt want to dismantle our existing EV3 kit which was built as a R3ptar so we purchased another set in new and sealed condition from Ebay for about £200.

My partner quickly built the Mindcub3r from the instructions here: MindCub3r for EV3 (

It took her a few hours and she left it for me to do the software installation part the next day.

The build was fairly straightforward but I spotted a couple of small pieces that were out of place and corrected these to ensure the model moved as expected. I then downloaded and installed the Lego Mindstorms software and followed the instructions above.

When I ran tried downloading the required software from the PC to the brick it kept erroring and complaining that it could not find various blocks. I wenbt back through the instructions again and realised I missed the step where you install the RGB Color sensor software. This was done and the software successfully downloaded to the brick.

After a quick trip to Smyths toys to purchase a genuine 3×3 Rubiks cube for £9.99, I tried to run the software on the robot for the first time. The brick beeped but nothing happened. After a few basis checks we noticed a low battery icon the brick and replaced the new (cheap) batteires with some Duracell batteries and ran the program again. This time it did its reset procedure and then asked for the Rubiks cube to be inserted. It scanned the cube, did its calculations and solved the now mixed up Rubiks cube.

It works most times but not always and I attribute this to ambient light levels and some movement of the Rubiks cube in its cradle. Over the coming weeks i will try some modifications and see if I can get a 100% success rate. Its still so cool to see it in action solving the Rubiks cube. Now to try to solve it by hand!