Cycloidal Cam-Law, Motion-Law

Cycloidal is a Traditional Motion-Law.

Segment-Editor AND Blend-Point Editor

CAN specify the:

Position at the START of the segment.

The Position motion-value usually flows from the Previous-Segment to the START of the segment.

CAN specify the:

Position at the END of the segment.

CANNOT specify the:

The Velocity values at the Start and End are [they are 0 units/s ]

The Acceleration values at the Start and End [ they are 0 units/s2 ]

The Jerk values are a function of the Positions at the Start and End of the segment, and its duration.

Note: You can edit Segment Editor Parameters of the Ramp Motion-Law to give this motion-law.

See Also: Getting Started Tutorials: MotionDesigner - 4: Edit the Start of a Traditional Motion-Law

Motion-Law Cycloidal


The Motion-Law is a Sine function when viewed in acceleration.

Position, Velocity and Acceleration Continuity
Finite Jerk

Motion-Law Coefficients

Velocity Coefficient: Cv = 2
Acceleration Coefficient: Ca= ± 6.28
Jerk Coefficient: Cj= ± 39.48
Jerk at Cross-over: Cj(co)= ± 39.48
Max Jerk = Displacement × Cj ÷ T3

Application Notes:

Dynamic Performance

This Motion-Law is recommended in applications where the period ratio is near to 5 when the input drive is stiff and the shaft speed does not fluctuate significantly under load. It has the good acceleration characteristics at the load and should be used in systems where low residual vibration (vibration after the end of the motion segment) is desired.

Pressure Angle Considerations

It gives a relatively large pressure angle - and so might need a large cam for a given lift and predetermined pressure angle limits, to reduce it.

Drive Torques

This Motion-Law is recommended in applications where no sudden change of input torque is a requirement. Its torque characteristics are particularly good in relation to the other Traditional Motion-Laws when the period ratio is less than approximately 10.

Tutorial and Reference Help Files for MechDesigner and MotionDesigner 13.2 + © Machine, Mechanism, Motion and Cam Design Software by PSMotion Ltd