<< Click to Display Table of Contents >> Navigation: MechDesigner Reference & User Interface > 2.3 PartEditor: > Geometry > Add Transition Curve 
The TransitionCurve is not available with the Trial License.
It is ONLY available with the Premium License.
The PSMotion TransitionCurve© is used to eliminate:
•the PolygonalAction, also referred to as ChordalAction, and
•the Linear VelocityDiscontinuity
each time a chainlink moves onto a chainsprocket (chaintooth).
Standard Sprocket and Polygonal Action The sprocket with number of teeth, with a tooth pitch, , rotates at a constant speed, (RPM). In the top image, the chain is tangent with the PitchCircle of the Sprocket. However, when the sprocket rotates by radians, the chain link is nearer to the center of the sprocket. Therefore, as the chain moves up and down, the effective radius of the sprocket changes to give a uneven, nonconstant chain velocity. The linear speed of the chain is maximum in the top image.
The linear speed of the chain is a minimum in the bottom image.
The e LinearAcceleration of the chain is discontinuous at the instant the chain starts to move upwards. PolygonalAction creates two(2) problems •Velocity Variation in the Chain In the general case, if a Driving Sprocket is rotating at constant Angular Velocity, the chain does not move at constant Linear Velocity. The ratio of Maximum and Minimum Velocity increases as you reduce the numberofteeth on the drive sprocket. •Tension Variation in the Chain. As a chain link engages with a tooth, the chain accelerates, and thus there is a tension variation. Also, the pitch of the chain link is not constant. Usually, it is recommended that you use more than 17 teeth on a standard sprocket. Bicycle sprockets have fewer, but the derailleur compensates for the velocity and tensionvariations. 
Toolbar : 
PartEditor : Geometry Toolbar > TransitionCurve 

Menu : 
PartEditor : Add menu > Geometry submenu> > TransitionCurve 

To add a TransitionCurve
You can see that the Transition Curve is easy to add. However, it must be used with Pulleys and Chains to be useful.
A Tutorial will show you how to apply the Transition Curve to a LongLink Chain.
