Current Projects:
Pinball Project
CNC Router
PIC Computer
LED Sign 2003

CNC Router

For Engineering Open House 2003, SigArch built a simple CNC router, with the intended goal of milling printed circuit boards and simple 3D parts. The project won Third Place in its category from Engineering Council at EOH, and tied for the "Best Overall Showing" award from ACM.

Based on a kit acquired from HobbyCNC.com, the router is controlled via a freely available G-Code interpreter called EMC, developed by NIST. We generated G-Codes for height map images using a Perl script. A Dremel tool is moved by three 60 oz-in stepper motors, with a cutting area of approximately 24x8 inches, and vertical motion of about 1 inch.

Here's some videos of the router in operation. For a demo, we showed the machine cutting foam since it is soft enough to cut very quickly. To view, you'll need an XviD codec, such as ffdshow. Click on the links to download the videos.

millvideo.avi (1.8MB) - Watch the router cut some foam into a jagged pyramid
mill_objects.avi (1.1MB) - See some of the objects we made
mill_letters.avi (12MB) - We also drew posters for our display using a marker attachment.

Example G-Code File

EMC uses standard G-Code files to control the Dremel motion. To create these files for testing, one of our members developed a Perl script which converts height maps, encoded as standard image files, into G-Code. As an example, we started with the following JPEG file:

After editing the script to specify the size of our foam block, the bit size, and the maximum cutting depth per pass, we generated the following G-Code file:

face.nc

The resulting object can be seen in the "mill_objects" video above.

The source code for the script can be downloaded from the link below:

hmap.pl

Current Status

(3/17/03) - EOH is over. We'll continue to improve the router, most important to make it actually mill circuit boards as planned.

Links

LinuxCNC, home of EMC software on Linux.
DesKAM, home of DeskEngrave and some Windows CNC software.

Project Sponsors

Thanks to HobbyCNC for donating both plans and parts to build the router.

Thanks to Drill Bit City for donating various cutting bits.