I have been busy with a variety of things CNC related.
Eames house bird
For one of my first real projects I had always planned to make my own Eames house bird. I have been continuing to learn new CAD/CAM skills for this project, and believe I now have a test ready to mill. Learning the different F360 3D toolpaths for this project has taken time but is rewarding.
At the same time I have been learning more about the CAM side of things, particularly the main tool paths and parameters that will enable the successful milling of plastics and aluminum.
I have spent some time working to incorporate my Drewtronics probe into the workflow of my ATC set-up. I could easily assign the probe as a tool, but the challenge was to get the tool offsets correct. Since I am using ISO20 toolholders, all my tools are referenced in relation to each other based on the touch off on my auto tool setter. This worked well for my probe as its trigger force was greater than that of the tool setter. The challenge was to figure out a way to compensate for the small probe offset - difference between when touching material and triggering. I was able to use 123 blocks and my test indicator to determine this, and once measured, I modified the tool (probe) offset value in the tool table accordingly. I can now do an auto tool change to tool #99 (my probe), and it will accurately determine the X, Y, and most importantly Z zeros relative to all my other tools. I am working on a safe way to have the probes cable permanently attached throughout this whole process - tool pick up>probing>tool return.
Machinable wax milling
I continued my work to mill wax. I am using it as a ‘safe’ way to test the accuracy and precision of my probe and tool offsets, as well as getting a better working knowledge of basic tool paths - facing, 2D adaptive, 2D contour, chamfering, etc. I am also more confident in my ability to use F360 subroutines to get past the limitations of the ‘free’ version. The linked video shows 5 operations, using 4 different end mills, all run from one main program and its linked subroutines. It does add more work compared to having F360 do it, but it saves me having to buy a license (at least for now as I learn).
My next goal is to produce videos of my CNC milling plastic and aluminum using a variety of feeds and speeds, and tool paths. I had always wanted to share these results with others who are interested, but I am still learning and experimenting with the best ways to do that.
My first few videos were using the camera of my BB phone - not ideal. I then planned to build a RPI based camera. I decided to take advantage of the network hardware I invested in for my home automation, which currently includes two 150W POE network switches that power my security cameras. I purchased an inexpensive POE camera online, and printed a temporary mount for it. I like the simplicity of only having one cable, as well as the fact the the video stream is available, and can be controlled, from anywhere. I am happy with the quality, and will look at options for similarly simple yet effective lighting. For now, I think this will work. The only thing I will need to design is protection for the lens once the hot aluminum chips start to fly.
I am still working on ideas to further protect the linear motion hardware of my CNC. The aluminum side panels and raised Y axes are working really well, but I found during my wax milling experiments the chips still flew over the panels. I am currently designing panels that will clip onto the X50 rails at their ends. These will ride along with the X axis and offer a bit more protection, at least near the cutting area. My initial prototype design is below.