The first step is to install the pillow block shaft supports
as shown in Figure 2. The supports are held in place with
two #10-24 x 1-1/4” machine screws. The screws are
secured (Figure 3) with a #19 washer, #6 washer, #10 lock
washer, and finally a #10-24 x 1-1/4” hex nut. At this point,
the nuts should only be finger-tight. The shaft supports
should look like the ones shown in Figure 4. Next, the
shafts are inserted through the upper pillow blocks, and
two 8 mm trucks are added as shown in Figure 5.
The shafts are pushed through to the lower pillow
blocks and secured with the set screws on the shaft
supports as shown in Figure 6. The bottom of the shaft
should be flush with the bottom side of the lower pillow
blocks. Don’t worry about the excess shaft that is sticking
out above the upper pillow blocks. Later, you will install a
motor mount to the shafts.
The Z carriage plate should be created from a piece of
3/4” stock. I recommend melamine coated particle board.
The plate has four holes for each truck and two holes in the
middle to mount the ACME nut. Several additional holes
were added for attaching the spindle mounts. The truck
and ACME nut holes have a 3/8” pocket so the heads of
the hardware won’t interfere with the spindle (Figure 7).
Two square recesses were added to the rear side of the
Z carriage plate. These allow the plate to clear the lower
pillow blocks (Figure 8). The plate is secured to the four
trucks with 16 4 mm x 16 mm machine screws. A #8
washer/lock washer combo is also added as in Figure 9.
Once the carriage plate is secured to the four trucks,
move it all the way to the top and tighten the screws on
the upper pillow blocks. Next, move the carriage plate to
the bottom and do the same with the lower pillow blocks.
Once you are happy with the movement of the carriage,
tighten all the nuts.
This completes the KReduCNC Z carriage assembly. As
stated earlier, the excess shaft lengths on the top of the Z
carriage will be used to support the Z motor mount and
later to secure hoses and/or cables.
Next month, we will start working on the drive
34 SERVO 07.2016