With the CNC Router fully operational, I turned my attention to stampmaking. The hope is that I will be able to draw custom stamps for my wife or others to help with various inkcraft projects.
After flailing around a bit with trying to use standard cam programs to make my stamp, I found F-engrave which can do magic. I have v-shaped engraving bits which can cut different sizes based on how deep the bit digs into the wood. With just the sharp point, you can score a thin line. With the whole bit in the wood, you can dig out a large channel. F-engrave understands this property and so can make a tool path to precisely cut out fine patterns.
There are four different cuts which need to be done. First a rough pass with an 3mm bit to clear away all the material not near a boundary. Second, a v-bit tracing of the outline which moves up and down to account for how thin the gaps must be. Third, a v-bit cleanup is done. Areas outside of the outline but too small for the roughing are cleaned away. And finally, the box around the design has to be cut out of the board. F-engrave can generate the first three tool paths and save them to different files. You need to use a standard CAM program to do the fourth one.
There are two gotchas here to be wary of. You want to scale the design before loading it into F-engrave. That will make it easier to ensure that the cut out tool path is correctly aligned to your engraved area. I screwed this up and ran a bit through my beautiful engraving. Also, make sure your art is already at the origin before importing it. If it is offset, the tool path F-engrave generates will be offset as well.
You can see my stamp attempt turned out pretty well before I accidentally carved across it later. The material is linoleum. I have read a few places that linoleum can work as a stampmaking material for CNC and you can find a few places that sell linoleum mounted to wood.
I decided to try a cheaper solution. I bought a linoleum tile from the local hardware store that had glue on the back. I just attached it to a small piece of wood and thought I was good to go. The real problem came when I tried to cut it out. The glue was not strong enough to hold a small section of linoleum on so when my cutout chipped off the linoleum around a stamp, the insides started shifting with the stress of cutting and I had to hit the emergency stop.
In order to make more progress, I will have to find a stronger adhesive to attach the tile to the wood. Or I will have to break down and buy pre-mounted stock online. So far I have learned a lot but have no stamps yet. Hopefully I will succeed soon.