RepRap for Science—How to Use, Design, and Troubleshoot the Self-Replicating 3-D Printer - Open-Source Lab: How to Build Your Own Hardware and Reduce Research Costs - page 116

FIGURE 5.19 A completed frame with x , y and z .
The last step to complete the main portion of the mechanical assembly is to atach the x -stage
to z -stage. Take the couplings that couple the shaft to the motor and clean them out. These
couplings take a pair of M3 × 20 screws and M3 nut and M3 washers and they it into the nut
traps on the coupler. Mount the coupler and the z -axis threaded rod (210 mm M8 threaded
rod) as seen in Figure 5.20 . Please note that the couplers are printed in ABS for flexibility. The
coupling ends may need to be reamed out with a drill bit, however, ensure that there is a snug
it after reaming and prior to tightening the screws. 11 Pull the x -axis up—use a wire to tempor-
arily tie it to the top frame and put two M8 nuts on the z -axis threaded rod on both sides.