When we export cam-coordinates to SolidWorks, the coordinates of the cam in SolidWorks becomes the XYZ table of a Curve feature.
After the transfer is finished, we must use the Convert Entities sketch tool to convert the Curve feature to a Spline sketch-element. We extrude, or cut, the Spline to become the cam surface.
A 'standard rotating-cam' is a closed shape. The contact-point between the cam and the cam-follower moves around the cam continuously as the MMA increases from 0 to 360.
It is easy to export and extrude these cams to SolidWorks.
However, with a 'Slot-Cam*', the contact-point may not move along the cam steadily. SolidWorks may not be able to create the Curve feature.
This topic describes how to solve this problem.
* Any cam in which the contact-point does not move steadily along the cam.
If the contact-point does not continually move along a cam's surface, there are two possible complications
If the cam-follower changes its direction, the contact-point of 'Cam 1', as calculated by MechDesigner, moves from one cam-flank to the other cam-flank
*'Dithers' : small changes in direction
If the cam-follower becomes stationary relative to the cam, the contact-point also becomes stationary. While the contact-point is stationary, the cam-coordinates become the same values, even as the MMA increases.
When the cam-coordinates have complications as described in A or B, or the two, SOLIDWORKS cannot create the Curve feature.
Example of a cam with the two complications.
Refer to the image to the left:
Sliding-part moves horizontally. A 'connecting-rod' joins the sliding-part to a point that has a complex 'looping' motion' as identified by the Trace-Point.
Thus, the sliding-part moves to the right and to the left, but with a complex motion, rather than move with a simple motion that is to the right and then to the left.
Each time the sliding-part changes its direction, the contact-point moves from one cam-flank to the other cam-flank.
Because MechDesigner draws the cam from cam-point to cam-point, a line is drawn across from one cam-flank to the other cam-flank.
Before we export the cam to SolidWorks, we must remove the two 'complications'.
There are two ways:
The Slider should:
The Rocker* must:
* Or Slider.
Steps to 'Linearize' the Independent Input to the Cam.
The full stroke of the sliding-part in the original model is the 'Sliding-Part Range'.
There are number of ways to measure the Sliding-Part Range. For example, connect the output of the Measurement FB* to a Graph FB, or a Statistics FB, and scrutinize those values.
* We use a Measurement FB to measure the position of the Sliding-Part in the original model. Thus, this FB is already available.
The input to the Slider and the Motion FB for the Rocker should increase linearly with a displacement range equal to the Sliding-Part's displacement range.
Add a Linear-Motion and a Gearing FB and connect them with wires to the Motion-Dimension for the Slider.
We need the motion-values at the output-connector of the Gearing FB to have a range equal to Sliding-Part Range. Thus the Gearing Ratio in the Gearing FB dialog-box should be:
Gearing Ratio = Sliding-Part Range/360.
If, with the original model, the Maximum Measurement is 340mm, and the Minimum Measurement is 20mm, then the Range is 340-20 = 320mm.
Thus the Gearing Ratio = 320/360 = 0.88889. Enter this, as an equation, [that is, enter exactly 320/360] in the Gearing Ration in the Gearing FB dialog-box.
Connect wires from the output-connector of the Linear-Motion FB to the Gearing FB to the input-connectors of the Motion FB and the Motion-Dimension FB.
Now, the Cam-Coordinates will not change flanks.
When you export the cam, SolidWorks can create the Curve entity and the Cam feature.
Note: You may need to delete the last point in the saved cam-coordinate data or from the Curve feature in SolidWorks.