LEGO Mindstorms NXT Mindcuber, solving Rubik cube.

This robot was built using a LEGO Mindstorms NXT set. This is one of the older sets - they can now be found selling on Ebay and similar for around $100. There are newer Mindstorms sets - and Mindcuber is also available for those; they solve the Rubik cube faster than the NXT set does.
At the end, I show the external battery adapter plate I designed for the NXT. This allows the use of a large external battery (or PSU), which is often to be preferred. As standard, the NXT runs on six AA batteries - and it eats them pretty fast when running robots like this one. My design is on Thingiverse. www.thingivers... It requires printing on a 3D printer, and then a little soldering to complete.