The working angle of the scissor support arm in a stationary scissor lift platform depends on the lifting height, platform size, and arm length. It is the angle between the scissor arms and the horizontal plane during operation.
Key Definitions
θ (Theta): The working angle of the scissor arms.
L: Length of one scissor arm.
H: Current lifting height.
C: Compressed (minimum) height.
W: Distance between the scissor arm pivot points on the base.
Working Angle Calculation
The scissor lift mechanism forms a right triangle, where:
The hypotenuse is the scissor arm length (LL).
The opposite side is the lifting height minus the compressed height (H−CH - C).
The adjacent side is half the platform width (W/2W/2).
Using trigonometry:
sinθ=H−CL\sin \theta = \frac{H - C}{L} θ=arcsin(H−CL)\theta = \arcsin \left( \frac{H - C}{L} \right)
Example Calculation
For a 1m × 1m platform:
Assume the scissor arm length L≈0.71mL \approx 0.71m (calculated from previous answer).
Compressed height C=0.2mC = 0.2m.
At maximum lifting height H=1.2mH = 1.2m:
θ=arcsin(1.2−0.20.71)\theta = \arcsin \left( \frac{1.2 - 0.2}{0.71} \right) θ=arcsin(1.0/0.71)\theta = \arcsin (1.0 / 0.71)
Since 1.0/0.71>11.0 / 0.71 > 1, this suggests a fully vertical position (90°), meaning the theoretical lift height might be overestimated or the arm length needs adjustment.
For practical designs, most scissor lifts work between 15° (fully lowered) and 75° (near maximum height).
Conclusion
The working angle varies with lifting height. You can use the sine function to calculate the angle for any given height. Let me know if you need help with a specific lift design! 🚀
