operating 52 servos with arduino

Hello, I would like to ask what would be the best set up for driving 52 6V servo motors with Arduinos: my questions fall into following: 1) how many servos should i attach to one Arduino and which Arduino board would be the best? 2) now i am testing 6 motors on Arduino Uno with external power supply. Whenever I upload a sketch motors start moving before executing the program itself. How to eliminate that?

Thank you very much in advance! Katya

which Arduino board would be the best?

The Mega, it can support a lot more servos than the Uno, can't remember how many look it up.

Whenever I upload a sketch motors start moving before executing the program itself. How to eliminate that?

Put a 10K pull down resistor on all the outputs going to the motors.

The standard Servo library controls upto 12 servos per 16-bit timer. The Uno has one 16-bit timer, the Mega four 16-bit timers, so 12 and 48 servos respectively (a little short of 52, alas,
it might be possible to tweak the Servo library to support 13 servos per timer to fix that).

Alternatively there are shields that drive multiple servos in various ways I believe.

Thanks so much!