I think it will be hard to reduce the average size of this NTX cube solvers
Mindcuber for NTX 2.0 called my attention because the turntable and the arm that moves the cube seems more secure that the tiltedtwister's ones.
My old tiltedtwister for NTX 1.0 is reliable to solve a cube with modified stickers,but it is generally slow, around 4 to 5 minutes and 40 to 70 moves to solve a more complex scramble. Sometimes the move is so strong that ejects the cube out of the turntable and you have to give a "hand" to the robot, but generally works great.
With webcams attached to the NTX 2.0 brick, it is a whole other level, for instance here in the forum i have recently checked another thread very impressive solving a micro-cubeviewtopic.php?f=1&t=23795&start=0&hilit=robot
On YouTube we can find many videos including solving a 7x7x7:http://www.youtube.com/watch?v=b5b9BIBu ... re=related
This Brazilian Robot CUBE PRIME is developed to solve a cube amazingly in less than a second and holds the cube by it's centers:http://www.youtube.com/watch?v=YL2AzBYo ... re=related
We can notice that this other robots using webcams and android cellphones are pretty larger
But to do a NTX cube solver without a webcam with less pieces than the ones above (Mindcuber and tiltedtwister), maybe reducing one Motor and scanning and moving the cube with just the turntable and the only one arm, by attaching the Infrared/Color Sensor on top of this arm. This could reduce the accurace of the scanning and the moves also.
What i think can work to reduce some lego pieces is removing the NTX head the "ultrasonic" sensor, it is only used to tell if a cube is ready to be done, this can be accomplished by pressing one NTX button to tell that the cube is ready on the turntable...
Maybe someone it is working on something like this right now...