Sorry for being a pain, but I wondered if I could ask how the sprockets attach to the motor shaft and axle where the axe is? Once you have them attached, is it a case of Mount the motor and axle and then attach the chain to size using a chain link remover to get the size you want? Are there any motors that have common shaft sizes I should look out for etc? This looks like an active weapon I could manage but just need a nudge in the right direction.