Why CAD? Getting Started with Onshape
Learn what CAD is, why FTC teams rely on it, and how an Onshape document is organised into Part Studios, Assemblies and versions you can share with your team.
In this lesson you will
- Explain at least three reasons FTC teams design in CAD
- Describe the difference between a Part Studio and an Assembly
- Identify how versions and history protect your team's work
- Set up a shared Onshape document for your team
Lesson
CAD stands for computer-aided design. Instead of drawing a part on paper or cutting metal straight away, you build an exact 3D model on the computer. You can rotate it, measure it, change a dimension in seconds and check whether it fits with other parts before any material is touched.
Why FTC teams use CAD
- Check fit before you build. You can see whether a motor collides with a wheel or whether an arm hits the frame while it swings.
- Save time and material. Mistakes found on screen cost nothing; mistakes found after cutting aluminium cost a part and an afternoon.
- Make custom parts. CAD files can be sent to a 3D printer, laser cutter or CNC machine, or printed 1:1 on paper as a drilling template.
- Work as a team. Everyone sees the same model, so builders, programmers and drivers can discuss the same design.
- Explain your robot. Clean CAD screenshots make your engineering portfolio and judging interviews much clearer.
CAD does not replace quick prototypes. Cardboard, zip ties and spare kit parts are often the fastest way to test whether an idea works at all. A good rhythm is: rough prototype to prove the idea, then CAD to make it accurate, strong and repeatable.
Meet Onshape
Onshape is a professional CAD system that runs entirely in a web browser. There is nothing to install, it works on most school computers and Chromebooks, and your work saves automatically to the cloud. Onshape offers free education accounts for students and educators, which is why many FTC teams use it.
Inside an Onshape document
All your work lives in a document. A document is like a project folder that contains several tabs along the bottom of the screen. The two tabs you will use most are Part Studios and Assemblies.
| Tab type | What it holds | Use it for |
|---|---|---|
| Part Studio | Sketches, features and one or more parts | Designing the shape of parts, often several related parts together |
| Assembly | Instances of parts connected by mates | Showing how parts fit together and how they move |
| Drawing | 2D views of parts with dimensions | Printing templates or sharing dimensions with someone who builds the part |
In a Part Studio, parts do not move; you are designing their shapes. Every step you take is recorded in the feature list on the left, in order. In an Assembly you bring parts in, connect them and make them move like the real robot.
History, versions and sharing
Onshape records every change in the document's history, so you can always look back. A version is a snapshot you create on purpose and give a name, such as a design you are about to print. Versions cannot be changed later, which makes them a safe checkpoint. You share a document with teammates using the Share button and choose whether each person can edit or only view it.
- 1Pick an ownerOne student or the coach creates the team document so it has a clear owner.
- 2Name it clearlyUse a pattern like team number, season and subsystem, for example a document just for the intake.
- 3Share itShare with every teammate and mentor, giving edit access to those who will design.
- 4Split the workAgree who works in which tab so two people are not changing the same sketch at once.
Key terms
- CAD
- Computer-aided design: creating exact 2D and 3D models of parts on a computer.
- Document
- An Onshape project that holds all the Part Studios, Assemblies and other tabs for one design.
- Part Studio
- An Onshape tab where you create sketches and features to design the shape of one or more parts.
- Assembly
- An Onshape tab where parts are placed and connected with mates to show fit and motion.
- Version
- A named, permanent snapshot of a document that you can always return to.
Practical exercise
Set up your team's CAD workspace
- 1Create an Onshape education account and sign in from your school or home computer.
- 2Create a new document named with your team number and the word Practice.
- 3Find the default Part Studio tab, then add an Assembly tab and rename both tabs clearly.
- 4Share the document with at least two teammates and your coach.
- 5Create a version called Setup complete and find it again in the document's history.
Knowledge check
Answer every question, then check your answers.