In this course, we learned to program gcode using HSM to machine parts on a Haas Desktop Mill. The stock we used was polyurethane foam, which was good for learning CNC machining because it is hard enough to be “machined”, while being forgiving enough to not escalate basic mistakes. The Haas Desktop Mill is also a good machine for learning the basics of CNC. We learned to manually set up G54 offsets and tool length offsets, and manually changed tools with tool-specific collets. Some examples of the tools we used are a flat end mill, ball end mill, drill, edge finder, and a test indicator. Though some of the work was manual, the mill has a standard Haas controller, so the skills we learned for working on the desktop mill are transferable to other Haas machines.

The two main pieces of software we used in this course were Flashcut, and Autodesk HSMWorks embedded in Solidworks. We used Flashcut CNC 4.55 in the first part of the course to visualize and check hand-written gcode. One of the first labs we did, and also one of my favorites, was writing gcode to write “UCSB” with a pen plotter in the mill. Instead of a tool in the collet, we used a pen to write on paper attached to a clipboard. Below is the toolpath generated in Flashcut, and the actual drawing made by the machine.

Once we learned more about writing gcode and about using the mill for actual milling operations, we wrote a few programs by hand for making 3D parts. Below is a toolpath generated by Flashcut for code I wrote by hand, and the resulting part made using the desktop mill.

Though using Flashcut was convenient for checking basic code, making more complex parts manually was quite slow, so we transitioned to using HSMWorks to generate toolpaths instead. In addition to being faster than handwriting code, we were also able to utilize the “Stock Simulation” feature in Solidworks to visualize how each machining operation would remove material from our stock. Seeing the virtual part in 3D as it was being “milled” in the simulations gave me a much better understanding of, for example, how the radius and geometry of a tool affects how operations are defined. Below is an example of the CAD of a part, and the physical part resulting from using code generated from HSMWorks.

When comparing the results of using Flashcut to check hand written code, and using HSMWorks to generate toolpaths, the finished part is the same as the planned design in both cases, but I believe using HSM is more efficient for most 3D operations. In cases like simple facing and drilling operations, writing code by hand or using VPS on the Haas mill is understandable. However, the fine control over numerous aspects of machining and availability of features like stock simulation make using HSMWorks a favorable option for CNC machining tasks.

Below is a list of parts I made in lab, following basic instructions and part drawings. Though the part had to be made specific to its design, we were free to use any operations we saw fit to make it, especially for later labs when we used HSMWorks. With every project, I got more familiar with the desktop mill, and learned about more efficient ways to machine parts.