as when accuracy is required.
to increase size: loosen & unscrew rear locking nut closest to drive shaft while holding blades from slipping out, now screw & tighten front locking nut allowing blades to slide along the slots in the main body until blades meets rear locking nut to secure blades into position.
to reduce size: loosen & unscrew front locking nut while holding blades from slipping out, now screw & tighten rear locking nut allowing blades to slide along the slots in the main body until blades meets front locking nut to secure blades into position. 