Now that we’ve completed the chassis and are moving onto some of the other rover components, I’ve had the opportunity to take on some components which present a bit more variety in the manufacturing arena. One of my research interests lies in high-speed and high-productivity machining technology, and I’ve gotten the opportunity to try out some new tools and toolpaths on some of the rover’s larger components. I’ve always been a big fan of Lakeshore Carbide’s variable flute endmills for aluminum, particularly their 3 flute ZrN coated models. They can take aggressive feedrates at the full 12000 rpm maximum of our Haas VF-4. The coating holds up well, and the razor sharp flutes leave an awesome surface finish. The variable flute and 3-tooth design combats vibration, even in thin wall and floor situations. With this part, I went for a 3/8″ tool and a troichoidal peel milling toolpath, with a full depth cut 7/8″ deep, 0.040″ radial engagement, and 240 inches per minute feedrate (linear equivalent 300 ipm). An air blast was used for cooling and chip evacuation. The total cycle time was 6 minutes with a fully engaged metal removal rate of nearly 7 cubic inches per minute during the roughing operation. Video to be posted shortly.