Chapter 18: Design Your Robot from Scratch

You've learned skills across 17 chapters, and now it's time to use them to design your own robot. Don't worry -- you don't need to create a perfect design on your first try. Even professional teams iterate many times before finalizing their robots.

This chapter doesn't have step-by-step instructions -- because you're ready to work independently. We'll just give you direction and tips; the actual work is up to you.

A. Planning Phase (Think Before You Build)

Before opening Onshape, answer these questions:

What tasks does your robot need to accomplish? (Pick up balls? Shoot balls? Move blocks?)
What drive type will you use? (Tank drive? X-drive? Mecanum wheels?)
What subsystems do you need? (Drivetrain + intake + shooter? Drivetrain + gripper + lift?)
What are the approximate dimensions? (Remember the VEX limit: 18" x 18" x 18")

Write It Down!

Draw a simple sketch on paper with approximate dimensions. It doesn't need to look pretty, but you must draw it out -- many problems become obvious when you sketch them.

💡 Suggestions

For your first design, don't make it too complex -- a drivetrain + one simple mechanism is enough
Make sure the drivetrain works first, then add mechanisms
Reference robots you've seen on YouTube or at competitions, but don't copy them directly -- understanding the principles matters more than copying the shape

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Checkpoint 1: Have you drawn a paper sketch?

Draw your robot's approximate layout on paper. Mark the drivetrain dimensions, subsystem positions, and drive type. It doesn't need to be precise -- the key is thinking through the overall plan.

B. Creating the Document Structure

Create a New Document

Open Onshape → Create a new blank document → Name it "Team [Number] - [Season] Robot v1"

For example: "Team 1234A - High Stakes Robot v1"

Choose a Document Organization Method

Remember the single-document vs. multi-document approach from Chapter 12? Most VEX teams recommend using a single document organized with tabs:

Tab	Suggested Name	Contents
Tab 1	Full Assembly	The main assembly -- where everything comes together
Tab 2	Drivetrain	Drivetrain sub-assembly or Part Studio
Tab 3	Intake / Mechanism	Your scoring mechanism
Tab 4	Custom Parts	Part Studio for custom parts

Create an empty assembly in the Full Assembly tab -- this is where you'll eventually put everything together.

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Checkpoint 2: Is your document structure set up?

Confirm that your Onshape document is created with at least a Full Assembly and a Drivetrain tab.

C. Start with the Drivetrain (You Already Know How!)

Review what you learned in Chapters 4-6 -- this time you're on your own, without step-by-step instructions.

Guidance Tips (Not Steps)

Decide the drivetrain dimensions -- a good starting point: 15" wide x 15" long, leaving room for mechanisms
Insert C-Channel from the VEX V5 Parts library in the length you need
Add motors, wheels, bearings, and chain (just like in Chapters 5-6)
Save with Ctrl+S as you go (even though Onshape auto-saves, it's a good habit)

⚠️ Having trouble?

Go back to Chapter 5 and Chapter 6 for the steps
Check the First Aid Guide for common mistakes
Search the Onshape community for "VEX drivetrain" to see how others do it

When you're done, don't forget to create a Version snapshot (taught in Chapter 10) -- record your first milestone.

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Checkpoint 3: Is your drivetrain assembled? Can you see it in Full Assembly?

Your drivetrain should have a C-Channel frame, motors, wheels, bearings, and chain. Insert the drivetrain sub-assembly into the Full Assembly tab.

D. Add Your First Mechanism

This is the most exciting part -- designing a scoring mechanism!

Start Simple

Browse the Onshape community for examples of similar mechanisms to see how others did it
Create an In-context Part Studio in the Custom Parts tab (taught in Chapters 7-8)
Sketch → Extrude → Assemble back into Full Assembly (taught in Chapter 9)

Not sure how to design it? → The next chapter (Chapter 19) covers detailed mechanism design strategies, including common VEX mechanism types and design approaches. You can read it first and come back.

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Checkpoint 4: Have you added at least one additional mechanism to Full Assembly?

Whether it's a simple plow or a complex intake, as long as you've added a mechanism beyond the drivetrain, you're done.

E. Iterate and Improve

It's perfectly normal for your first version to be imperfect! Professional teams typically go through 3-5 major iterations before finalizing their robots.

Good Iteration Habits

Use versioning to record every major change -- so you can always go back to a previous design (taught in Chapter 10)
Get feedback from teammates -- use the comment feature to @teammates and have them review your design (taught in Chapter 10)
Check that dimensions meet the rules -- make sure it doesn't exceed 18" x 18" x 18" (Chapter 20 covers this in detail)
Don't be afraid to start over -- if a design isn't working, boldly restart from a version snapshot

✅

Checkpoint 5: Have you created at least 2 version snapshots?

Open your document's History and confirm you've created at least 2 Versions. Each version represents a design milestone.

What You Learned in This Chapter

You just completed the entire process from blank document to robot! Key steps:

Plan -- Think it through before you start; draw a paper sketch
Structure -- Set up your document and tab organization
Drivetrain -- Build it independently using the skills you've learned
Mechanism -- Add a scoring mechanism
Iterate -- Version management + feedback-driven improvement