■ FIGURE 7. Magazines used to
raise rear support off work surface
to allow clearance for hex nuts.
Keeps unit stable for several
make it easier to install the threaded
rods which tension the frame ends
and hold the base together. The
magazines provide clearance for the
nuts on the end of the threaded rods.
The holes that these threaded rods
go into are surrounded by a slightly
cone shaped recess which helps to
guide the rods into and through the
The precision-ground shafts are
put into the gray bushings and the
end tubes are put in place. The
bushing plates that later connect to
the gantry base are added next.
(Make sure you install these the right
way around as it is tedious to turn
them around later.) Finally, the other
frame end plate is added and held in
place with washers and nuts added
loosely (Figure 8).
At this point, the frame can be
put flat on the work surface and the
gantry is loosely bolted to the gantry
bushing plates. Alignment of the unit
takes place at this point (before the
lead screws are added). By moving
the gantry and Z axis assembly back
and forth with a finger while carefully
snugging up the existing bolts, you
can tell if things are in alignment by
how easily things slide on the
Thomson shafts. Once you have the
alignment feeling right, you can
tighten the bolts about a half turn
past finger tight.
Now that we have the table
done, it’s time to add the lead screws
that the motors will use to control
the motions. There are several
washers and locking collars which
were in small, well labeled bags
(Figure 9). It is important to put these
parts on in the correct order. (Note:
The Z axis assembly already has its
rods and lead screw installed, so we
are only dealing with the X and Y axis
here.) Once the lead screws are
installed, I again turned them by
hand to make sure there was no
binding anywhere across the range of
motion for both the X and Y axes.
■ FIGURE 8. Front support attached
to tension rods (inside silver tubes)
via acorn nuts and washers.
blue motor goes on the Z axis and
the yellow motors go on the X and Y
axes. Someone was thinking ahead
when they thought of color-coding
the motors! A quick tip: Before
mounting the motors, you may want
to consider grinding a flat on the
shafts. This will allow the coupler
set-screws to make a better seat.
AND NOW, FOR SOME
At this point, the complete $599
FireBall V90 CNC
router is assembled. It’s
now time to move on
to the electronics package. In the standard
motor package, the
■ FIGURE 9. Starting at top center
and going clockwise: table supports,
tool holder, Z axis assembly, hookup
wire, fuses, fuse holders, power cord,
lead screw bearings and clamps, and
assorted bags of hardware.
■ FIGURE 11. Z axis motor in place —
ready to tighten screws.
■ FIGURE 10. Motor hardware
— metal washers go between
motor and nylon standoffs.
December 2008 71