Drill Basics

For most robotics work, we are drilling in metal, mostly aluminum. We also drill plastics and wood on occasion. Different materials act differently when being drilled, so it is important to know what kind of drill is best for each material, and how fast to spin and feed the drill. There are lots of fancy and expensive drills out there for various materials, but we will concentrate here on things we are likely to find in our shops.

Tip Angles

Most twist drills we are likely to see in our shops have either a 118 degree or 135 degree tip.

Aluminum

Aluminum is considered a "stringy" metal because it forms long chips when it is cut. In fact, some cutting tools will form a single chip several feet long when drilling a hole in aluminum. A big challenge is providing an escape route for the aluminum chip. In twist drills, the recommended type is one with a "fast spiral" design.