Motors and Movement - Printing in Plastic: Build Your Own 3D Printer - page 223

On the 3D printer body, add the small collar mating piece to the collar already attached to the lead
screw, as shown in Figure 13-13.
Figure 13-13. Add the collar mating piece to the collar attached to the lead screw.
Carefully insert the Z-Axis Motor Mount by pushing the four (or three) 3-1/2” machine screws into
the holes on the Z-Axis Bearing Support (Part L). Push down until the collar on the Z-Axis Motor Mount
is secured properly in the collar mating piece. This may require some patience; don't rush it or push too
hard. When the collars are mated, secure the four (or three, if you had to remove one) 3-1/2” machine
screws with four nuts, as shown in Figure 13-14. Use the other two nuts on each 3-1/2” machine screw
to tighten (push) against the and the Z-Axis Bearing Support. Note in Figure 13-14 that the motor's wires
are pointed towards the rear of the machine (this will be helpful later during the wiring portion of the
project).