[lincpimp]

I did a writeup somewhere on her of how I tured a 6mm 1717 motor shaft down to 5mm.

Bacially I clamped the motor in a vise, and then used a drill press with a larger grinding stone (think dremel bit but bigger). I used an esc and radio to spin the motor, then turned on the drill press and manually fed the stone into the shaft.

My reasoning was that the shafts may be hard material, and grinding stone would work better than a file. Plus having everything setup parallel/perpendicular would hopefully produce a better result.