Modified trapezoid

This profile is synthesized from the Cycloidal and constant acceleration/deceleration elements.  As in the modified-sine, the "C" Factor determines the amount of the cam segment that is allotted to the cycloid at either end and in this case the middle.  From figure 6, C/2 of the segment is used at either end for the cycloid to accelerate and decelerate the follower.  For the acceleration, the first 1/4 of the cycloid is used and for the deceleration, the last 1/4 of the cycloid is used.  In the middle, the remainder of the cycloid is used to bring the follower from acceleration to deceleration.  As the "C" Factor increases the curves will look more like a cycloid and a decrease will approach the acceleration- deceleration elemental profile.  This profile is also available in just acceleration or deceleration.

 

NOTE If a "C" Factor other than 0.25 is used, the cam will have to be fabricated via the Post Processor in Cam Designer SETM, or a post processor that uses the CAD translation of the cam surface.

 

Modified-Trapezoid Properties

The displacement and velocity curves have zero slope at the ends.

The velocity curve is linear between (C/2 and (1-C)/2) and ((1+C)/2 and (2-C)/2).

The velocity has zero slope at the mid-point of the segment.

The curves are symmetrical; therefore, the displacement at the mid-point is 1/2 the total.

This profile is also available in just acceleration or deceleration.

 

NOTE:          

1.The curves shown in figure 6 are for a rising translating follower or an oscillating follower that is rotating CCW.

2.The X axis is θ/β from 0 to 1

3.The Y axis is based on a displacement of 1.

Figure 7

Modified Trapezoid Profile