Shooter Type Comparator
Flywheel, catapult or puncher for the shot you need. They differ far less in cycle rate than people assume, because all three are limited by the same thing.
Inputs
The shot you need
From the launch studio, working back from the distance you need.
What you can spend
Share of motor output that becomes object energy. Low for all of these; measure yours and compare.
The match
A match runs 120 s, and you spend some of it driving.
Results
Energy per shot
—J
Fastest possible cycle
—sec
Set by power alone.
Cycle you need
—sec
Is the rate achievable?
—
Motor power available
—W
Flywheel RPM, single wheel
—
Flywheel RPM, two wheels
—
Shots the power allows
—
Under the first mark there is room to spare. Past the end, the fire rate you want is impossible at this power, whatever you build.
The three, side by side
| Mechanism | Cycle floor | Shots available | Consistency | Space | Best when |
|---|
The cycle floor is the same for all three on purpose. It falls out of energy and power alone, so no mechanism beats another on it. Pick between them on the columns to the right.
How this is calculated
Every launcher here is an energy pump. Work out the energy the object needs and everything else follows.
energy per shot = ½ × object mass × exit speed² cycle floor = energy per shot ÷ (motor power × efficiency)With your numbers
That cycle floor is a hard limit, not an estimate of a particular design. No arrangement of gears or bands beats it, because it is just power and energy. It is the number to check before committing to a mechanism, and it is usually the reason an ambitious fire rate does not work out.
What actually separates them
- Flywheel. Stores energy continuously and bleeds it out per shot, so it can fire the moment it has recovered and degrades gracefully: fire early and the shot is merely slow. That soft failure is its real advantage. It needs constant power to hold speed, and it is sensitive to compression and object condition.
- Catapult. Stores everything, releases it at once, which is efficient and gives a repeatable shot because the energy is set by the draw rather than by a speed you have to hold. It fails hard: fire before it is cocked and nothing useful happens. It also needs swing room, and the arm keeps a big share of the energy.
- Puncher. A catapult that moves in a straight line. Compact, no swing arc, and easy to feed from a magazine. Stroke length limits how much energy you can store, so it suits lighter objects and shorter ranges.
Consistency is the thing to weigh
A catapult drawn to a hard stop delivers nearly the same energy every time, which is why they are accurate. A flywheel's shot depends on the speed at the instant of firing, so consistency depends on recovery and on how patiently the code waits. Therecovery analyzer measures that directly, and the accuracy analyzertells you whether it is aim or consistency costing you points.
Efficiency is the number to distrust
The default here is a guess and no better than that. All three are lossy in different ways: flywheels to slip, catapults to band hysteresis and arm mass, punchers to friction. Measure one shot on the mechanism you build, work back to the energy that reached the object, and replace it.
Sources & assumptions
Motor power ratings of 11 W and 5.5 W and the match timing are VEX published figures. Energy, power and the cycle floor are basic mechanics.
Efficiency is estimated and is the weakest number on the page. It varies by mechanism and by build, and every cycle time scales directly with it, so treat the comparison between mechanisms as more reliable than any single cycle figure.
The consistency and space columns are judgements about how these mechanisms behave, not measurements. They are here because the numbers alone do not separate the three, and pretending otherwise would be the bigger distortion.
Flywheel RPM figures assume no slip, so they are the minimum you would need in the ideal case. Real builds need more, which theflywheel studio covers.
- VEX Robotics — V5 Smart Motor & Gear Cartridges (276-4840) — checked 2026-08-17
- V5RC Override Game Manual v1.1 (2026-27) — checked 2026-08-17
Save this run, and compare
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Save this as evidence
Collects what you entered, what came out, how it was worked out, and anything the tool flagged, with a timestamp and a version so someone else can reproduce it.
This is evidence, not a notebook entry. It deliberately does not write your problem statement, your reasoning, or your conclusion, because under RECF rules an Engineering Notebook has to be the students' own work and no tool may generate or organise its content. Take the numbers, decide what matters, and write it yourself.