Pacific Rim: Hydraulics vs. Electrics

“To fight monsters, we created monsters.” The Jaegers in Pacific Rim—Gipsy Danger, Striker Eureka—are distinct because they move heavy. You can feel the weight. Every punch is driven by massive pistons slamming forward. This is the power of Hydraulics.

In FTC, our robots are swift, snappy, and buzz like power drills. This is the power of Electrics. Why don’t we build mini-Jaegers? Why is the industry moving away from fluid and towards wire?

The Fluid Power of Hydraulics

Hydraulics use non-compressible fluid (usually oil) to push pistons.

• How it Works: You have a pump. It pushes oil into a cylinder. The oil pushes a rod out.
• The Pros: Insane Force Density. A hydraulic jack the size of a bottle can lift a car. If you want to punch a Kaiju in the face, you use hydraulics because steel gears would shatter under that impact.
• The Cons: Heavy. Messy. Slow. You need a tank, a pump, hoses, valves, and fluid. And if a hose breaks? You leak oil everywhere. In a competition, that’s an instant disqualification (and a huge mess).

The Electric Precision of Motors

FTC robots (and modern robots like Spot and Atlas) are primarily Electric.

• How it Works: Magnets spin a copper coil (DC Motor).
• The Pros: Clean. Fast. Silent(ish). Precise. A wire is flexible and light compared to a hydraulic hose.
• The Cons: Less raw force per inch.

How We Mimic Strength (Gearboxes)

Since we can’t use hydraulics, we use Mechanical Advantage to fake it. We take a fast, weak motor and run it through a massive Gearbox (e.g., 100:1 ratio).

• The motor spins 100 times.
• The arm moves 1 time.
• Result: The torque is multiplied by 100. This is how a tiny electric motor can lift a 30lb robot into the air. We trade speed for “Jaeger Strength.”

Pneumatics: The “Air Muscle”

There is a third option used in FTC: Pneumatics (Air). It’s like hydraulics, but uses compressed air instead of oil.

• The Look: It uses pistons (Silver cylinders).
• The Feel: It gives you that linear “Punchy” motion. Phhhht-CLACK!
• The Physics: Air is compressible (Squishy). This acts as a shock absorber. It’s perfect for claws or punchers where you want a fast, snappy action without the weight of a motor.

Conclusion

While electric motors are the standard for precision robotics (like surgery bots or agile walkers), heavy industry (excavators, cranes) still rules with Hydraulics. So, if you are building a robot to sort LEGOs, go Electric. If you are building a robot to cancel the apocalypse, stick with Hydraulics. For everything in between? Maybe try Pneumatics.