Hi gurus, I was hoping you guys can help me with a little something: I have just purchased a 12V DC motor with a shaft diameter of 5.4mm (Oddly enough, the description on the ebay page says 5.5mm, but the technical drawing attached, says that its 5.4mm). In any case - i am looking for a gear that i can attach onto this motor. However, all the gears out there have their measurements in imperial. My question is: What bore diameter should i be looking for to attach to my motor, that has a 5.4 - 5.5mm shaft? 3/8" seems slightly too big, and 5/16" seems a little too large. Any suggestions? (Sorry if this seems like a silly question) Thanks!