All-

I recently finished the first successful prototype of what I'm calling a "regiftcard". Basically, I take an already-used iTunes or other gift card (~0.7mm thick ABS plastic), design a 3D puzzle that can be punched out and assembled. I left little tabs to hold the nearly-cut pieces in place in the card. You could do this with unused gift cards as well, of course running the risk it will get ruined on the mill.

I used Inkscape to design the ship model (I scanned a similar item and then traced it to paths), then used the gcodetools inkscape plugin to generate the gcode to translate for our mills, then milled the puzzle using a 0.025" end mill. Having a 3 ton 3-phase machine drive a 0.025" mill to cut plastic was quite the thing. My first attempts did not work out so well, as my 1/32" end mill was just a touch too large, and the .650mm drills Chris had first broke and then melted the plastic. However, using the 0.025" end mill (MSC part #04468666) worked nearly perfectly. It is actually just a hair too tight in the parts that need to be fully inserted, so for future designs I might make those parts cut with multiple paths.

Some of the CNC details:
* 2000 RPM
* 125 mm/min feed rate
* 100 mm/min plunge rate
* 1mm plunge to cut through the material fully

This sort of project is a very accessible introduction to CNC milling if you are interested in learning that sort of thing. I've attached some photos. The forum won't accept .svg files, but just contact me if you want a starting point or a closer look.

My next steps with this are to design some sort of dinosaur or winter-themed puzzle. If you have any ideas, let's hear them!

Scott

Ha! Very cool!