Scissor lifts appear in car jacks, warehouse platforms, aerial work platforms, laboratory jacks, and loading dock levelers. Despite the simple appearance (two crossed arms and an actuator), the force analysis is far from trivial: actuator force approaches infinity near collapse, stability degrades with height, and the choice of actuator type and joint configuration changes everything. This simulator provides complete analysis across all these dimensions. #ScissorLift #MechanismSimulator #ForceAnalysis
Open SimulatorHeight, Velocity, Acceleration
Full kinematic profiles across the operating angle range. Platform height follows h = nL sin(theta), but velocity and acceleration reveal non-obvious behavior: the platform decelerates as it rises even with constant actuator speed.
Force and Mechanical Advantage
Actuator force varies as 1/tan(theta), creating a hyperbolic spike near collapse. Compare actual mechanical advantage (including link weight) against ideal MA. Critical for hydraulic cylinder and motor sizing.
Joint Pin Forces and Link Stress
Center pin and base pin resultant forces across the full range. Per-side force breakdown for eccentric loads. Bending stress estimates for structural design of the scissor arms.
Energy, Power, and Stability
Potential energy accumulation, power requirements, and stability analysis with tipping angle and safety factor. Essential for hydraulic power unit selection and safe operating envelope design.
Real-Time Animation Watch the scissor lift rise and fall with properly rendered rounded-bar arms, pin-hole joints, base and top platforms, and load arrows. All elements scale proportionally across presets from tiny lab jacks to large aerial platforms.
Twelve Analysis Plots in Four Groups Kinematics (height, velocity, acceleration, actuator length, base spread), Force Analysis (actuator force, mechanical advantage with ideal MA overlay, joint pin forces, link stress), Energy (potential energy and cumulative work), and Stability (tipping angle and safety factor on dual axes).
A/B Configuration Comparison Save one configuration as Experiment A, change any parameter, and run Experiment B. Both datasets overlay on every chart with distinct colors and line styles.
UDL and Point Load Support Default is uniform distributed load (UDL), representing pallets, equipment, or people spread across the platform. Switch to point load with configurable offset to analyze eccentric loading, tipping risk, and per-side force imbalance.
Two Configurations, Three Actuator Types Symmetric (both pivots slide) or left-pinned (one pivot fixed). Horizontal-base hydraulic, horizontal-center lead screw, or diagonal cylinder. Six combinations, each with different force, stroke, and efficiency characteristics.
Eight Real-World Presets Warehouse Lift, Car Jack, Aerial Platform, Lab Jack, Loading Dock, Auto Hoist, Electric Table, and Work Table. Each configures link length, stages, load, mass, actuator type, and joint arrangement for a specific application.
Professional Downloads Export PNG charts, design specifications with manufacturing tolerances, lab report templates, and full kinematic/force datasets.
The simulator includes eight engineering presets representing real applications:
| Preset | L (mm) | Stages | Load (N) | Config | Actuator |
|---|---|---|---|---|---|
| Warehouse Lift | 700 | 3 | 2000 | Symmetric | Horizontal Base |
| Car Jack | 300 | 1 | 5000 | Left-Pinned | Horizontal Base |
| Aerial Platform | 1200 | 3 | 3000 | Symmetric | Horizontal Base |
| Lab Jack | 80 | 1 | 50 | Symmetric | Lead Screw |
| Loading Dock | 400 | 1 | 8000 | Symmetric | Horizontal Base |
| Auto Hoist | 500 | 2 | 10000 | Left-Pinned | Diagonal |
| Electric Table | 350 | 1 | 1500 | Left-Pinned | Lead Screw |
| Work Table | 450 | 1 | 3000 | Symmetric | Diagonal |
Each preset configures all parameters to values representative of the application: actuator type, joint configuration, operating angle range, link mass, and actuator speed.
The simulator implements exact analytical solutions for all configurations:
Height per stage:
h = n * L * sin(theta)Actuator force (symmetric, horizontal-base):
F = W_eff / (2 * tan(theta))
where W_eff = P + (total link weight) / 2Actuator force (left-pinned, horizontal-base):
F = W_eff / tan(theta)Diagonal actuator length:
D = L * sqrt(0.09 * cos^2(theta) + 0.49 * sin^2(theta))Mechanical advantage (ideal, symmetric horizontal-base):
MA_ideal = 2 * tan(theta) / nTipping angle (stability):
tipping = arctan(worst_margin / cog_height)
where worst_margin = min(halfSpread + cogX, halfSpread - cogX)Where L = link length, n = number of stages, P = platform load, theta = half-angle from horizontal.
Nine structured experiments are available in the Mechanism Design and Simulation course, each with Python analysis scripts and design questions:
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