which Neu 1515 has the most torque/power?

[suicideneil]

Clamp the tip of the shaft in a vice, then file away with a narrow flat file. Once that section is done (doesnt have to be a big flat spot going half way through the shaft), just finish up the tip by holding the flat spot with some pliers, and work away on the tip until it mathces the rest of the flat spot. Common sense and iniative really.

All the average RCer neads is:

bench and small vice
dremel or similar rotary tool
cordless drill
selection of drill bits
seletion of files- large and small
hammer and center-punch
hacksaw

Thats all I have, and I can custom fab varies things like a new chassis plate, and new motor mounts.