Summercamp CNC Project

I contributed to a summer manufacturing camp project for high school students, organized by my employer. Leveraging my design skills, I assisted in developing the project itself, the associated manufacturing processes, and the necessary tooling. This was a highly rewarding experience. 

With the tank selected for the project, I began designing and working on a prototype stereo over the weeked.

Component cutouts were created using a designed template for accurate marking and tracing. Manually cutting and refining these shapes with a Dremel burr bit proved time-intensive, requiring 45 minutes per unit. This manual approach was impractical for the limited time available to the campers, and presented safety concerns with high-speed cutting tools. A CNC solution was deemed necessary, but budgetary constraints precluded purchasing a new system. Fortunately, an older, non-functional Inventables CNC machine, utilizing a Dremel as a spindle, was available (saved from the dumpster). This machine was substantially rebuilt, retaining only the original custom aluminum extrusions. 

Significant design improvements were implemented. The original Dremel tool was upgraded to a 500W brushless, air-cooled spindle motor with an ER11 collet system. The Z-axis, previously a 1/2" all-thread rod, was replaced with a 1/2" ACME thread and a custom zero-backlash internal dampener. The Y-axis plates were redesigned and fabricated from 1/4" cold-rolled steel (CRS) to enhance rigidity and increase Z-axis travel. The original GT2 timing belt system for the X and Y axis, which proved insufficient for the heavier gantry and exhibited excessive backlash, was replaced with ACME thread and nut combinations, driven by more powerful NEMA 17 stepper motors. 

The CNC bed was constructed from a planed teak cutting board, chosen for its affordability, relative flatness, and dimensional stability across varying environments (from my garage to an air-conditioned conference room). Spaced and drilled holes with zinc threaded inserts provide flexible fixturing options, surpassing the availability and cost of appropriately sized T-slot solutions. While a MIC-6 cast aluminum fixture plate was considered, the estimated $1200 cost was prohibitive for this personal project. 

To provide intuitive CNC control for the students, a user-friendly interface was prioritized over a complex, purpose-built controller. This approach avoided the need for extensive training and ensured a more accessible experience for high schoolers.