This is Part 2 of the Mantis 9 build instructions. Part 2 takes you through motor/leadscrew installation and final assembly.
For assembly of the X, Y, and Z axes see Part 1...
Make the Leadscrew Nuts
Installing the Y-Axis Leadscrew and Nut
Installing the X-Axis Leadscrew and Nut
Installing the Spindle Bearings
Installing the Z-Axis and Stepper Motor
Installing the Z-Axis Nut
Drilling the Spindle Shaft
Using the spindle coupler as a drill bushing as described above may damage the precision bore on the inside. For this reason, use this coupler as a spare part only and install a fresh coupler on the machine.
After drilling your spindle shaft, use the Low Cost Spindle 2.0 page as a guide to assemble the remaining spindle components. When cutting/installing the PVC tubing coupler, leave about 1/4" between the bottom of the motor shaft and top of the spindle shaft. See the following photo for reference. (Photo courtesy FabLab Vestmannaeyjar.)
After the spindle is installed in the Z axis, attach the motor to the wooden motor support plate with hot glue, but do not glue the three metal motor support pins (1/8"x1.5"). Connect a 12V power supply to the spindle motor and monitor the motor current. While the motor is running, adjust the position of the motor on the pins (up/down and rock side to side) to get the lowest current reading. At 12V, try to achieve less than 1 amp of current draw. Once the position is adjusted, secure the pins with hot glue.