I have been making progress on the g-code splitting program (yet to be named). I think I have all of feature for the initial release, including the graphic user interface (GUI), complete. I have more testing to do before I post the program. I have included some pictures from a test cut. The picture above shows half of a split image cut. The picture below shows the same board with the second half of the image cut. To the left of the large eagle cut using the splitting program is a smaller eagle that is as large as I could cut on my machine without splitting the image and flipping the board between cuts.
I used pins on the back side of the board to maintain alignment between the first and second cuts. The picture below shows the pins on the back side of the work piece and the pin holes in the scrap board mounted to my CNC machine.
I am not sure how long it will be before I release the splitting program bu I expect it will be one to three weeks from now.
PVC pipe with engraving on inside.
Using the g-code interpreter that I am developing for the g-code splitting program I read some g-code generated by F-Engrave and mapped the coordinates to the inside of a cylinder. I had a Dremel bit with a small ball at the end (larger than the shank). So I was able to cut a design into the inside of a cylinder with the tool axis aligned with the pipe axis.
Engraving inside of a PVC pipe.
I thought it was interesting but I have no application for it yet. I also tried cutting a small lithophane but the results were marginal. See the photo below.
I am working on a new program (Python script) that can split an existing g-code file into two halves. This will allow users to take a file run half of the file then rotate the work piece 180 degrees then cut the second half. This will effectively allow a user to cut designs twice as large as the cutting area of the machine. (As long as the physical rotation is done accurately).
A significant portion of this project is writing the g-code interpreter. The interpreter is the code to read and understand the g-code input. With the g-code interpreter is written other g-code bending operations can be performed. Similar to what CNCWrapper (http://www.cncwrapper.com/) does. In fact wrapping g-code around the A-axis may be a future project.