So, the entire week was filled with failures of getting the other side of the knife mold cut on the desktop cnc. I ended up adding 1mm of stock to the machining surface to prepare it because I couldn’t quite get this wood piece flat. Also, I made some improvements to the control system. Specifically, I upgraded the raspberry pi controller to an Intel Compute Stick which was nice because now it has an easy headless interface that is more stable on the WiFi than the raspberry pi. If this machine stayed on a personal wifi network, the raspberry pi would probably be fine. The other update was to add a webcam to check in on the machine progress, added a connection for the vacuum, and connect everything to an uninterruptable power supply. Unfortunately, even with all the updates I was having the machine stop arbitrarily in the middle of the job.
In my frustration, I ran across a blog post about the same problem. It was an excellent thread with some nice brainstorming about troubleshooting this system. My personal takeaway was to disconnect and disable the hardware limit switches to see if they were accidentally causing the machine to shutdown. After making that change I started my job yesterday about 3pm and left it to finish over night. My result is pictured below. Note, I already dissembled the hold downs for the pattern wood.
The two pictures below show the cope and drag sides of this pattern. The top down shot looked like an optical illusion to me so I also took a picture from the profile with a pencil lying on it to show what goes down and what sticks up. 
Next step is to create the box for these patterns and see if I actually hit the dimensions of the mold lock I was aiming for. Everything looks nice right now, but I have some feeling that I may need to back the lock edges from each other to make sure they sit deep enough. I certainly don’t want these to rest on the lock edges and not on the parting surface. Anyway, a small victory to start the week after frustration…
Dr Monroe Thoughts 