NOTE: Lumenlab has since changed its offerings a bit,
and is now selling an assembled machine controller
rather than discrete electronics boards and components.
But if you prefer to roll your own controller, you can still
purchase the DIY machine kit by itself, and use stepper
drivers from one of the many vendors who offer CNC
drivers and driver kits. A PC with a parallel port, running the free and open source EMC2, makes a fine CNC
The basic machine assembly went pretty effortlessly, with almost no opportunity for mistakes.
Documentation and assembly instructions reside on
the Lumenlab website, and the companion forums
are full of helpful tips from other CNC machine
Once you get the machine all bolted together, you
need to use a framing square to make sure that the
X ways are perfectly parallel, and that the y-axis
carrier (gantry) is perpendicular to the x-axis. This
is referred to as tramming the machine.
The optional spindle kit for the micRo is a flexible
shaft, hanging grinding tool, and a set of mounts for
attaching the toolholder/chuck to the Z blocks. It
worked well for me, though you could easily mount
a Dremel, or other type of rotary tool, if you choose.
The spindle had more than enough power to cut
through hard plastic without bogging down.
Steve Lodefink ( firstname.lastname@example.org) is a designer by day,
and by night he likes to learn new skills. Building small
projects using fabrication methods and materials that
he has never tried is his hobby and his therapy.
Running a Job
There are two fundamental software steps to preparing a job for a CNC machine. First you have to
draft the part in a CAD (computer-aided design)
program. Next, you use CAM (computer-aided
machining) software to interpret the model and
generate the appropriate tool path for the machine
to follow. CNC tool paths are written in a language
known as G-code. The machine controller software
then uses the G-code as a map, and drives the tool
around appropriately to carve the piece (Figure A).
I have a confession to make: I’m not really up to
speed with CAD just yet, but I did find a cool CAM
program called Image to G-Code, which converts
a grayscale image into a cutting depth map. I fed
a photograph of a skull, along with the size of my
material and cutting tool, into the software, and it
generated the proper G-code to mill the photo into
a translucent material. I machined the image into a
sheet of white Corian acrylic, and when held up to
the light, it looks like the original picture (Figure B)!
I’ve got some CAD learning to do before I can
start making robot parts, but let me just say that
this desktop CNC tinkering feels good, and I’m really
glad I started with a kit.
Fig A: My micRo CNC robot, built from a kit. It was
easy. Fig. B: The bot milled this plastic to different
depths, using a simple CAM program.
Image to G-Code program: makezine.com/go/gcode
GeckoDrive (good CNC drivers): geckodrive.com
EMC machine controller software: makezine.com/
My build photos: makezine.com/go/lodefinkcnc