Gears
Spur Gears
The Spur Gear is the most common type of gear. It has straight teeth and is used to transmit motion between two parallel shafts. In your SPIKE Prime kit, these are the standard circular gears (like the 12-tooth, 20-tooth, or 36-tooth gears). When two spur gears mesh, they rotate in opposite directions.
Idle Gear
An Idler Gear is a third gear placed between a “driver” gear (connected to the motor) and a “driven” gear. It does not change the gear ratio or the speed of the output. Its primary purposes are to:
Gear Ratio
As the pinion turns, it moves the rack back and forth. This is commonly used in SPIKE Prime for steering mechanisms or forklift-style lifting arms.
- Gear Ratios: A Gear Ratio is the relationship between the number of teeth on two meshing gears. It determines how speed and torque (turning power) are traded:
- Gearing Up (Speed): A large gear driving a small gear. The small gear turns faster, but with less power. (e.g., a 36-tooth gear driving a 12-tooth gear creates a 1:3 ratio).
- Gearing Down (Torque): A small gear driving a large gear. The large gear turns slower, but with much more power—useful for lifting heavy loads. (e.g., a 12-tooth driving a 36-tooth creates a 3:1 ratio).
Rack and Pinion
A Rack and Pinion setup converts rotational motion into linear (straight-line) motion.
- The Pinion is a standard spur gear.
- The Rack is a flat, straight gear track.
Spike Prime Gears
Videos
- MultiGear -Spike Prime Gears (0’32”):
- 3 Levels of Lifting Attachments (1’32”):
- Converting Rotational Motion (4’07”):
- Sun and Planet Gear (0’17”):
- Lego Technic Gears #Shorts (0’33”):
- All About Gears Using Lego Gears (3’38”)
TASK
Using your Spike Prime kit, create models of the following, experimenting with different size gears.
Consider: What is “gear ratio” and why is it important?
