Background

In MechDesigner, you can save a cam as a DXF File. The DXF is intended for some CNC machines that do not have a spline option, or cannot open a STEP, IGES, STL, parasolid, or other 3D Cad file format.

In CAD, you often need to mate, or constrain, a cam follower to a cam face.

If you open the DXF File you save in MechDesigner in other CAD, and then extrude, you will see the cam face has a number facets and edges. In this case, you will not be able to easily make a mate between the Cam face and the Cam Follower.

The procedures given below give the best option when you want to use a Cam prepared in MechDesigner, but in an assembly prepared in CAD.

tog_minusIn MechDesigner

In the Cam-Coordinate Data dialog, you should calculate the Cam-Coordinates as:

Equal increments of the Master Machine Angle
Lines. NOT Arcs
Part Coordinates - see Note on Part Coordinates
Closed Cam
As many Points as necessary.

Finally, press the 'Send Cam Data to SolidWorks' button.

Make sure the SolidWorks is open, and a Part, existing or new, is the active document.

The data is sent to SolidWorks as a Curve Feature.

MD-SW-Curve

The Cam 'Curve' shows in the 'Front View in the Part'.

Note: If you want the 'Cam Curve' to be projected onto the XZ Plane or the YZ Plane then you must save the Curve data, and swap the X, Y or Z data with the zero set.

MD-SW-CurveExtruded

1.Select a Plane that is coplanar or parallel to the Curve you have imported.
2.Start a sketch on the Plane
3.Use Convert Entities in SolidWorks® sketch editor, to convert the Curve to a sketch
4.Close the Sketch
5.Use the sketch to Extrude the Curve.

You can see the Cam does not have any facets.

 

tog_minusOpen Excel®
1.Open the file, with file-type as... *.txt
2.Select a delimiter, as a ',' or 'tab'.

You want the 'X' and 'Y' Cam Points in separate columns, with each Cam Point in a new Row.

Experiment with the import options if necessary.

3.Tidy up the data, remove headers etc.
4.Move all the data so the first X Point starts at Cell A1, and the first Y Point at B1.
5.Add a Column for the Z-Axis, and fill it with Zeros (0).
6.If necessary, make the first and last point to be identical.

Experiment as necessary. Some CAD will close the cam for you, other CAD will not.

7.If necessary, scale the Cam-Data to the units you are working in your CAD
8.Save your data as an Excel® spreadsheet, for back-up purposes.
9.Save your Data to a NotePad® file.

You will use the file saved in Excel® or NotePad® to import into your CAD.

tog_minusImport Cam Data into CAD

The next steps depend on the CAD you are using.

plus        Solid Edge

hmfile_hash_c638c863

Select:

1.Surfacing tab → Curves group → Curves → Curve By Table
2.On the Insert Object dialog-box, set the 'Create from File' option and click OK.

Browse to your Excel® spreadsheet and click ‘Open’.

Curve by Table uses an Excel spreadsheet to define a construction curve. The spreadsheet, which is embedded in the Solid Edge document, allows you to better import and manage engineered curves.

md-solidedge-curvebytableparameters_zoom67

Curve by Table Parameters

Curve Fit

Linear Segment

Creates line segments between the data points in the table.

Smoothing Off

Applies the direct curve fit method to the data points in the table.  Using this method, the curve passes directly through the points.

Smoothing On

Applies the 'least squares' curve fit method to the data points in the table.  Selecting this option enables the tolerance drop list.  Using this method, the curve path is controlled by the tolerance value and does need to touch the points.

Tolerance

Allows you to specify a tolerance for the Smoothing On option.  Gives the maximum distance the curve can deviate from the points.

To create a curve using the Curve By Table command, or to edit an existing curve, Microsoft Excel® must be loaded on your machine.
To create a curve using the Curve By Table command, or to edit an existing curve, Microsoft Excel® must be loaded on your machine.

Curve End Conditions

Open

Allows you to specify an open curve. For example, the first and last data points do not touch each other or any part of the curve.

Closed

Specifies a closed curve. For example, the first and last data points can touch one another or any part of the curve. When this option is set, the Periodic and Natural options become available.

Periodic

Connects the first data point with the last data point to make a smooth tangent closed curve.

Natural

Creates a closed curve without a tangency condition.

Note: The 'Curve by Table' Feature will fail if the first and last data points in the spreadsheet are coincident. If you select 'Closed', delete the last point in the table that is coincident with the first.

Coordinate System

Allows you to select coordinate systems to offset the curve data to. Make the coordinate system prior to creating the curve through table of points.

number-of-points

Records the total number-of-points in spreadsheet.

Now, you can extrude the Curve as a Surface, I believe!

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