Rubik's cube solving robot

This blog is dedicated to build a Rubik's cube solving robot. I'll not give you any guarantee to even update this blog or finish it. I just want to share and discuss some ideas.

The first thing I did was to buy 3 Rubik's cubes at taobao.com (a kind of Chinese Ebay), each around 10 RMB.  I bought 3 pieces, because I wanted to avoid one or two samples are getting damaged during my experiments and evaluations and I needed then to find exactly the same kind of probes for my experiments again, which can be quite annoying.

The cubes I bought have a side length of 57 mm with standard surface colors: white, red, yellow, orange, green and blue. Firstly I modulated the cube in sketchup in a 3-axis Cartesian coordinate system as shown below:

I'll go for two 2-DOF-grippers to do all solving movements, similar to this one. Seems to be much more, but it can be all simplified to a two 2-DOF-gripper configuration. Next step is to calculate/evaluate the minimum opening range of the grippers.

The opening range of the gripper is simply the diagonal of the square. Pythagorean theorem:

With the sketchup measurement tool we find this result too:

Now we can start to design the gripper.

Gripper under design. 1 mm aluminum sheet, two 40 mm VEX gears, Tower Pro MG 995 servo:

Finished gripper design: