Chassis Design, Tools and Workshop Safety
Learn what a chassis does, how kit frames are built from channel and plates, and how to choose a simple layout. Then meet the tools you will use and the safety rules that keep everyone uninjured.
In this lesson you will
- Explain the job of a chassis and how it supports every other subsystem
- Identify common structural parts such as U-channel, extrusion, plates and standoffs
- Compare square and rectangular chassis layouts for a first robot
- Use hand tools correctly and follow workshop safety rules
Lesson
Every FTC robot starts with a chassis: the base frame that holds the wheels, motors, battery and electronics. Mechanisms such as an intake or a lift are added later, but they all bolt onto the chassis. If the chassis is bent, wobbly or too crowded, every later step gets harder. That is why experienced teams spend real time getting this first part right.
What a chassis actually does
A good chassis does four jobs. It holds the wheels in exact positions so the robot drives straight. It is stiff, so it does not twist when the robot pushes against something. It protects the electronics from bumps. And it leaves open space and mounting points for the mechanisms you will add later. A simple, strong, boxy frame does all four jobs better than a clever but fragile one.
Frames, channel and plates
Most beginner teams build from a kit of metal parts. These kits use a few repeating shapes. Channel is a long piece of aluminium bent into a U shape, with holes along it. Extrusion is a solid-looking bar with slots that accept special nuts, so you can mount parts anywhere along it. Flat plates connect pieces at corners, and standoffs are short spacers that hold two layers apart. All of these share a regular hole pattern, so parts line up without drilling.
| Part | What it is | Why teams use it |
|---|---|---|
| U-channel | Aluminium bent into a U, with a hole pattern | Very stiff for its weight; wheels and bearings mount directly into it |
| Extrusion | A slotted bar that accepts sliding nuts | Parts can be mounted at any position and moved easily |
| Plates and brackets | Flat or bent pieces with holes | Join channel at corners and add mounting points |
| Standoffs | Threaded spacers of fixed length | Hold two plates or layers a set distance apart |
Square or rectangular?
For a first robot, choose a simple square or rectangular frame made of four channel or extrusion pieces joined at the corners. A square frame turns evenly in every direction and is easy to make symmetric. A rectangular frame gives you more length for a mechanism at the front or back, and a longer robot often drives straighter. Either is fine. What matters is that opposite sides are the same length and the corners are at 90 degrees.
Kit-based building
Kit systems such as goBILDA and REV are designed so parts fit together without machining. Each kit has its own hole pattern, screw size and shaft shape, and the parts are designed to work together within that system. Mixing systems is possible but usually needs adapter parts, so for a first robot pick one main kit and stay with it. Read the kit's documentation and look at its example chassis builds before designing your own.
Tools you will use
| Tool | Used for | Tip |
|---|---|---|
| Hex keys (Allen keys) | Tightening most kit screws | Use the exact size; a loose fit strips the screw head |
| Nut driver or wrench | Holding nuts while you tighten | Hold the nut still and turn the screw, not the other way round |
| Combination square or ruler | Checking corners are 90 degrees and sides are equal | Measure diagonals; equal diagonals mean a square frame |
| File or deburring tool | Smoothing cut metal edges | Cut metal edges can be sharp enough to slice skin |
| Hacksaw or band saw | Cutting channel or shafts to length | Only with adult supervision and the part clamped firmly |
- Disconnect the battery before you work on wiring or anything that can move.
- Clamp parts before cutting or drilling; never hold small parts in your hand.
- Cut and push tools away from your body and fingers.
- Deburr every cut edge before the part goes on the robot.
- Keep the floor clear of screws and cables so nobody trips or steps on parts.
- Put tools back in the same place after use so the next person can find them.
Key terms
- Chassis
- The base frame of the robot that holds the wheels, motors, battery and electronics, and supports every mechanism.
- U-channel
- A length of aluminium bent into a U shape with a regular hole pattern, used as a stiff structural beam.
- Extrusion
- A slotted structural bar that accepts sliding nuts so parts can be mounted anywhere along its length.
- Hole pattern
- The fixed spacing of holes used by a kit so that parts line up and bolt together without drilling.
- Deburring
- Removing the sharp edges and small metal fragments left after cutting or drilling a part.
Practical exercise
Plan your chassis on paper
- 1Look at two or three example chassis builds in your kit's documentation and note what they have in common.
- 2Decide on a square or rectangular layout and write down the outside length and width, staying inside the size limit in the current Competition Manual.
- 3Sketch a top view showing the four frame pieces, the four wheels, the motors, the battery and the Control Hub.
- 4List every part you need from the kit (channel lengths, brackets, screws, bearings) with quantities.
- 5Set up your workspace: safety glasses for everyone, the right hex keys and a clear table, and review the safety list as a team.
Knowledge check
Answer every question, then check your answers.