There are a variety of things that can be done with a CNC router, like cutting gears and other parts, but one of the unique things that can’t easily be done with manual tools is engraving. I had read that this could be done using an extension for Inkscape, but as I’d never used it before, it took me a while to figure out how to do it correctly (the output code kept giving me some crazy circles like in the last picture in the article). Once I got everything correct, here are the results:
The trick (at least the one that worked for me), was to convert everything into straight lines and then generate the G-code. For some reason, before I did this the circles seemed to always screw up my code (I’ve been using Mach3 to run my router for those that are curious). My suspicion is that some wide arcs are interpreted as going the wrong way (counterclockwise instead of clockwise and vice versa). This would mean that instead of a tiny arc to go from one point to another, a giant circle is made to go the other way. That is my guess, but I have no way to verify it.
I’ll do a full tutorial about how I did it shortly (so check back) Here’s my Inkscape engraving tutorial, but basically I used Gcode tools, an extension for Inkscape, to generate a toolpath based on a path from a vector-graphics drawing (How Inkscape draws things, check out this Wikipedia article for more information). I’d never used Inkscape before, so this was a steep learning curve for me. The results look pretty good, but I’ve got a long way to go until I’m a CNC machining master.
If you’re wondering how I set up the clamping system on my machine, check out this post. For all other posts related to this machine, check out all my “CNC router project” posts. Edit 3/4/2012 – I’ve come a long way engraving stuff, check out the Clemson HDD clock that I engraved.
On a side note, I tried running this machine with the Z-axis up and the Dremel tool off before I did this (I zeroed the Z-axis in Mach3 well above the workpiece). The three servos working like this really sound pretty cool, so maybe I’ll put something up about that soon.