1.MECHDESIGNER MODEL

This model is the CamCo® Part Number M601RDM4H24-330 in (weblink) CamCo Catalogue, Page B-4.

•A Globoidal Cam.

•4-Stop Cam, with 12 Cam-Follower Rollers.

•Index motion: 'Modified Sine' but with 33% Constant Velocity – MSC33.

•Index-Period is 330º, Dwell-Period is 30º.

•Distance between the input and output shafts is 107.95mm (4.25").

There are two motions:

•The rotation of the 3D-Cam – constant angular velocity

•The rotation of the Cam-Follower Wheel – the index motion

2.SOLIDWORKS® EQUIVALENT ASSEMBLY MODEL

•We have transferred the 3D-Cams and the Cam-Blank to SOLIDWORKS® from MechDesigner to make the Globoidal Cam Part.

In SOLIDWORKS®, we have:

•Modeled a 'frame' to represent the Cam-Box and the two orthogonal axes.

•Modeled an equivalent Cam-Follower Turret (or 'Wheel')

•Modeled the axes of rotation of a Cam-Box

•Assembled the three Parts: Frame, Cam-Follower and Cam-Part (from MechDesigner).

Clearly, the Cam-Box and Cam-Follower Turret/Wheel are very simplified. However, they are configured in the same way as the Cam-Box in the catalog.

The 'Front' Plane of the 3D-Cam should be the 'Front' Plane in SolidWorks®.

3.SOLIDWORKS® 'MATES'

Here, we add mates (SolidWorks® terminology) that we want to control with motion-values from the MechDesigner model. The mates in the SolidWorks model are (see image):

1.Mate 1: ANGLE2 is between a Fixed and a Moving Plane in the 3D-Cam.

The 3D-Cam rotates when we edit the value of Angle2.

2.Mate 2: ANGLE1 is between a Fixed and a Moving Plane in the Cam-Follower Turret.

The Cam-Follower Turret rotates when we edit the value of ANGLE1.

The image to the left shows the two(2) mates in the Feature Tree.

The Mates Angle 2 and Angle1 are driven by the Cad Control Function-Blocks.

You can rename Mates in SolidWorks. Later, I renamed them to Output Cam-Follower and Output cam-shaft.

Notes on Angle Mates in SOLIDWORKS:

Angle mates in SOLIDWORKS® can not be negative. They can have a range from 0º to 360º'.

The output from an Motion-Dimension (Rocker) in MechDesigner has a possible range of -180º to 180º. Much larger if we select the Accrue Index Motion check-box in the Motion FB dialog-box.

The Positive and Negative directions of the Mate should be the same in SOLIDWORKS® and MechDesigner.

You should test which is positive direction in the Angle Mate Control in SOLIDWORKS.

The motion of the 3D-Cam (Input Shaft) and the motion of the Cam-Follower (Output Shaft) are in different Mechanism-Editors. We must make them available in one Mechanism-Editor.

We must add an indexing Cam-Follower Part in the Cam-Shaft Editor

In the image to the left Show Solids in Mechanism is Toggled IN'), the Part and the Function-Blocks in the 'Red Rectangle' have been added.

Note: Even though the Motion-Dimension value is 225º, the output value from the Angle Motion-Dimension FB itself is -135º!

As we cycle the Model in MechDesigner, the -135º value increases in the Positive sense to 0º and up to 225º.

The Angle Mate in SOLIDWORKS® is '+225º'.

Note: It is not possible to make angle negative in SOLIDWORKS®, thus we add 360 to –135º' to give 225º

We have configured the angle mate to increase in the same positive sense. To do this we:

•Add a Gearing FB, and edit the Add to Output parameter to 360º.

•Connect the Gearing FB to the Motion-Dimension FB.

•Add a Graph FB to help make sure the motions values that you want to connect to the Cad-Control FB input-connectors will agree with the required changes to the Angle Mate parameter in SolidWorks®.

STEP 1: Open SOLIDWORKS

STEP 2: In MechDesigner, Add a Cad Control FB to the graphic-area

STEP 3: Connect FBs with the correct motion-values to the Cad Control FB to control the Angle Mates in SOLIDWORKS.

STEP 4: Double-Click the Cad Control FB to configure it.

With the SOLIDWORKS model open:

STEP 1: Select the Enable CAD Control Function-Block option.

STEP 2: Click Get Dimensions

The dialog-box, 'finds' the correct mates in SOLIDWORKS.

STEP 3: Click the Get Dimension list, to see the Mates found in SOLIDWORKS.

STEP 4: Select the SOLIDWORKS Mates, top to bottom, that agree with the Motions, top to bottom, at the input-connectors of the CAD Control FB.

Note: I renamed the mates in SOLIDWORKS from Angle2 and Angle1 to 'Output CamFollower' and 'Input CamShaft'.

STEP 5: Click OK

Now, the positions of the Parts in SOLIDWORKS move when you move the Parts in MechDesigner.

The connection is slow – say a step per second.

Use the 'Step Forward', 'Step Backwards' or the 'Home' buttons – DO NOT USE THE CYCLE buttons.

It is possible to use the 'Interference Detection' and 'Clearance Verification' tools in SOLIDWORKS®.

STEP 1: Change the 'Units' in the 'Document Properties' of the 'Options' in SOLIDWORKS to mm with 6 decimal places

STEP 2: 'Step Forward' the cam-shaft in MechDesigner to, say, 18º, as indicated in the Master-Machine-Angle

The Cam-Follower moves to the angular position given by the Modified-Sine Motion-Law, with Constant-Velocity of 33%, in the MechDesigner and SOLIDWORKS models.

(If this does not happen the communication between MechDesigner and SOLIDWORKS has not worked.

Do not worry. Manually enter the angles in SOLIDWORKS.

you must read the two angles in MechDesigner and manually set the angles in SOLIDWORKS

STEP 3: In SOLIDWORKS, use the Clearance Verification Tool

STEP 4: Click the Cam-Follower Turret and the 3D-Cam

The SOLIDWORKS Clearance Validation Tool shows the clearance as 0.00389mm.

I typically put 5μm (0.005mm) clearance between the Cam-Follower and the 3D-Cam in the 3D-Cam dialog-box – dependent on the 3D-Cam or Cam-Follower Size

This means the data sent to SOLIDWORKS:

•Was calculated correctly in MechDesigner to less than 1.111μm,

and / or

•SOLIDWORKS gives the surface derived from the 3D-Cam 'Rims' to less than 1.111μm.