Machining

A list of subtractive manufacturing tools commonly used in Formula for any material. Theory, safety, pros/cons, photos, cost, etc... When this gets too large we can consider separating it into other pages.

Safety

If your team is going to be using any of the tools below, please wear the correct Personal Protective Equipment (PPE) for the work being done.

Typical shop dress code is: cotton short sleeve shirt, jeans, close-toed shoes, no jewelry, and hair tied out of the way.

Recommended PPE includes safety glasses and hearing protection. Occasionally additional PPE is required such as a full face shield, respirator, or gloves.

NOTE: Using rotating machines with gloves or a long sleeve shirt might seem safer, but it is actually more dangerous due to the risk of getting sucked in.

Grinder

Rotary Tool

Also known by the trade name Dremel®, the rotary tool is ideal for small and delicate work. Depending on the bit installed, the tool can grind, sand, cut, or polish.

Die Grinder

Die grinders are typically more powerful than a rotary tool. The extra power can turn larger bits. A 1" coarse grinding bit can be used to cope tubes.

Angle Grinder

Angle grinders are even more powerful than a die grinder but also larger, less precise, and more dangerous. Different disks can be installed on the tool for different types of work. A grinder wheel can quickly remove material. Flap disks are convenient for finishing or cleaning. Cutoff disks are for cutting ONLY! do not attempt to grind with a cutoff disk because they are known to shatter into a million pieces and hit you!

When using an angle grinder, be aware of where your sparks are going. Do not remove the shield! Disks can and will shatter.

Mills

A vertical milling machine with a vice and DRO installed

The most typical milling machine is the vertical milling machine. In this configuration, the workpiece held to the table typically within a vice and elevated with parallels. The table is controlled in the XYZ axes. The tool is held with a collet or drill chuck and spun by the spindle. The spindle speed and plunge axis is also controlled by the user.

Tools such as end mills, drill bits, reamers, fly cutters, and saws can be installed. Machining technique varies depending on tool type/material and workpiece material. Topics such as speeds and feeds, heat generated, and lubrication should also be considered.

Dimensions can be confirmed by either scribing and measuring or using a Digital Read Out (DRO) if installed.

CNC Machining

Not all teams may have access to a CNC. You do not need CNC to make a formula car but it is recommended for complex, high tolerance, or high quantity parts. Talk to local machine shops and trade schools, they may be willing to sponsor your team with CNC services.

Computer Numerically Controlled (CNC) machining is a process which takes programmed tool paths via user input in order to machine a part. Programming the tool paths is done in a Computer Aided Manufacturing (CAM) software, which allows the programmer to choose the tools used for machining and visually simulate the machining if the part. The program is then transferred to the machine to do the work.

• Complex shapes can be made with CNC compared to manual machining
• Parts, tools, and software can be more expensive than manual machining
• Involves additional programming time and testing
• Precision and finish is generally higher with CNC parts as everything is controlled by a computer and the ability to climb mill.

2 Axis

2 Axis machining generally the X and Y axis

Multi-axis

Multi-axis CNC Machining is any CNC machining performed on a machine with greater than 3 axis (degrees of freedom) control. Different variations

Further Reading

• MIT Machine Shop Videos (Youtube Playlist)