1. Don’t Let Your Wheels Fall Off!
VEX Collars & Spacers
Don’t Let Your Wheels Fall Off!

2. Axles Don’t Stay Where You Put Them
They can slide in TWO directions

3. Collars Attach to Axles
Tighten the set screw to attach to a square shaft
Use the small hex key. X

4. Use Collars Each collar stops the axle from sliding in one direction.
Place one collar after the wheel or it will fall off!

5. Spacers

6. Spacers help keep gears and wheels in place.

7. Your Turn What happens to axles if you don’t use collars?
How many ways do you need to stop an axle from sliding?
What characteristic do bearings and spacers have in common that allows for axel rotation?
The last question was added so that students can develop relationships among materials.

8. Resources
Inventor’s Guide: 3·4