Reference

Glossary

Every term of art used on this site, in one place. Wherever one of these words appears in the guides it is underlined — hover it for the quick definition, or click it to land here.

bottleneck: The single action the rest of the cycle is waiting on. Speeding up anything that isn't the bottleneck changes nothing about cycle time.
brown-out: A battery-voltage sag deep enough to reset or cripple electronics, typically when several motors draw hard simultaneously.
carriage: The final moving element of a lift — the part that carries the end effector and travels the full stroke.
cascade: The stringing architecture where all lift stages extend simultaneously at proportionally different speeds, so the load at the actuation point stays roughly constant.
constant-force spring: A pre-stressed coiled steel strip that pulls with nearly the same force (~1–2% variation) across its whole extension — the closest COTS match to a gravity load.
constant-torque spring: A strip spring transferred between two drums that delivers nearly constant torque over its rated turns; a drum of radius r converts that into constant line force F = T/r.
continuous: The stringing architecture where lift stages extend one after another, so the moving mass — and the gravity load — increases in steps as the lift rises.
COTS: Commercial off-the-shelf: parts you buy ready-made (cord, springs, brackets) rather than design and fabricate yourself.
counterspringing: Adding a spring system that offsets a mechanism's gravity load, so the motor spends its torque on acceleration instead of on holding the mechanism's own weight.
crane-style: A robot archetype that carries its horizontal extension (and often several actuators) on the vertical lift, making the moving mass unusually heavy.
creep: Slow, permanent stretch of an elastic material held under tension. The reason bungee cord needs periodic re-tensioning and replacement.
critical path: The chain of actions that sets the total cycle time. An action is only worth speeding up if it sits on this chain.
drum: A driven cylinder that converts torque to string force (or back) through its radius. Constant-torque setups use a storage drum and an output drum.
end effector: The mechanism the lift carries to do the actual game task — claw, bucket, arm, or intake. Its mass rides the lift and sets much of the gravity load.
force profile: How a spring system's output force varies across the lift's travel — linear for bungee, flat for constant-force, stepped or shaped for others. Matching it to the gravity load is the whole game.
free speed: The no-load end of the motor curve: maximum speed, zero torque. Real, loaded mechanisms always run somewhere below it.
gear ratio: The reduction between motor and mechanism. It trades speed for torque and decides where on the motor curve the loaded lift actually operates.
Hooke's law: F = kx: an ordinary spring's force grows linearly with how far it is stretched. The reason bungee force rises with extension while a gravity load doesn't.
linkage: An assembly of rigid links and pivots that transforms one motion or force into another — here, used to reshape a plain spring's force into a designed profile.
moment arm: The perpendicular distance from a pivot to a force's line of action. Changing it along travel is how a sprung linkage shapes its force profile.
motor curve: The plot of a DC motor's torque, current, and power against speed: torque and current fall linearly from stall to free speed, and output power peaks in the middle.
moving mass: The combined mass of everything currently in motion on the lift — slides, carriage, and end effector. Gravity load equals moving mass times g (times the lift-angle factor).
pretension: Stretch built into an elastic element while the lift is fully retracted, so the cord pulls with useful force from the very start of travel.
spool: The cylinder a spring coil or string winds onto. Constant-force springs mount on free-spinning spools; the lift's drive string winds on a driven spool.
stage: One telescoping section of a lift. Each stage rides on the one below it; the counterspring must handle whichever stages are moving.
stall: The zero-speed end of the motor curve: maximum torque and maximum current, zero output power. A lift held up by raw motor torque is stalled and burning current.
turn budget: The number of drum rotations your full lift travel requires, which must stay within a constant-torque spring's rated turns.
winch: The motor-driven spool assembly that reels the lift's string in and out. Constant-torque counterspringing concentrates its hardware here instead of along the slides.