Building this kit without a 3mm tap is a no-no!
Be careful with the tap, go STRAIGHT into the holes.
Be VERY careful of the 1st thing you need to tap. It is the 4mm droop screw holes. ONLY GO ABOUT 1/2 way in. If you go all the way through, your droop
screws will be loose.
Z now I know why Tobee gave spare spacers. It is to firm up the spur gear.