■ FIGURE 12. Stepper leads attached
to cable with solder and heat shrink.
I did this slightly different than
PROBOTIX since I used orange and
shield as V+ conductors (they only
use orange in the gray cable).
The motors are mounted using
nylon stand-offs (Figure 10), and
bolted to the top of the Z assembly
(Figure 11) and to the gantry or
frame side members. I followed the
illustrations in the instruction manual
and mounted the motors in the
standard locations. (Some have asked
■ FIGURE 14. Starting up EMC2 on
Ubuntu Linux.
■ FIGURE 13. 24V Power supply,
relay board, three motor drivers,
and breakout board mounted with
fuse holders.
if the motor can be mounted on the
back of the frame and John Hansford
has verified that it is possible to do
so, if you prefer.) While working with
the machine, I realized that even with
the motor wires disconnected, the
motors can be hard to turn. I added
some knobs (RadioShack part number 274-407) to the back shaft of
each motor so I could easily turn the
shafts for manual zeroing and to save
my fingers! Wiring the motors was
surprisingly straight forward. The only
trick was realizing that several of the
wires go to the positive motor supply
and can be connected together to
one wire in the cable (Figure 12).
Make sure you leave enough cable
length appropriate for each axis since
they all have different travel
distances. I mounted the motor
drivers, relay board, and breakout
board on a piece of wood that was
large enough to also hold the
power supply (Figure 13).
HARD PART’S DONE,
T SIOMFETWFOARRES!OME
■ FIGURE 15. Mach3 Software up and
running on Windows.
I had help from another
good friend, Robot Group member
and Linux expert James Delaney in
getting the Ubuntu Linux distribution,
EMC2 and Inkscape software up and
running on my desktop PC (Figure
14). After playing with the software
for a bit, I posted a question to the
FireBall forum asking questions about
Inkscape (a GNU/open-source design
software I was trying). I detailed how
I had encountered some difficulty
with the apparent lack of an integrated
software solution for both the design
and tool-path planning end of
things. I had a look around at the
commercial offerings and, after
reading some suggestions on the
forum, downloaded a trial version of
Mach3, an advanced CNC control
application (Figure 15).
Meanwhile, John Hansford
answered my posting (he’s quite
active in the forum) saying he
encountered similar issues and
suggested a software package from
Vectric called Vcarve Pro. I downloaded the trial version of the
software that allows you to try out
the design aspect and then cut the
example files on your CNC (Figure
16). John spoke with Tony McKenzie
at Vectric and arranged for a full
copy of VCarve Pro to be sent out to
help speed our preparations for
Maker Faire (thanks Tony and
Vectric!). I used VCarve Pro to
import several bit mapped
images and perform the tool
path planning for our Maker
Faire give-aways (Figure 17).
I think it’s pretty amazing
that there are so many
choices for for small-scale
CNC software including both
GNU/open-source, as well as
commercial applications.
My final approach was a
■ FIGURE 16. VCarve Pro with
example artwork.
72
December 2008
