How to prepare and import SOLIDWORKS Parts and Assemblies

We use the CAD-Line dialog-box | Solids tab to import SOLIDWORKS Part and Assembly documents.

Note: The correct 'Type-Library' file must be in the MechDesigner installation directory before you can import documents from SOLIDWORKS. See Install Type Library.

About Coordinate Systems in SOLIDWORKS and MechDesigner

We align a:

•Coordinate System in MechDesigner: Each CAD-Line has a 'Coordinate-System'

with a

•Coordinate System in SOLIDWORKS: We must add a Coordinate-System to the SOLIDWORKS document.

The 'Coordinate Systems' in SOLIDWORKS and in MechDesigner

Coordinate System

MechDesigner's Elements

SOLIDWORKS' Features

Origin...

...the start-Point of the CAD-Line

...the Origin of the Coordinate System

+XY Plane...

...the Mechanism-Plane

...the XY–Plane of the Coordinate System

+X–axis...

...the CAD-Line [from its start-Point to its end-Point]

...the +X–axis of the Coordinate System

+Y–axis...

...+90º from the +X-axis, on the Mechanism Plane

...the +Y–axis of the Coordinate System

+Z–axis...

...normal [⊥] to the Front-View, towards you.

...the +Z–axis of the Coordinate System

MechDesigner's Elements

CAD-Lines in a Part and how it defines the Coordinate-System.

There are two ways to add a CAD-Line:

•Automatically: along the centre of an Added-Part.
•Manually: use the Part-Editor to add one or more CAD-Lines to a Part, at any position and orientation.
This CAD-Line is automatically added with the Added-Part.

This CAD-Line is automatically added with the Added-Part.

The image shows and Added-Part and its CAD-Line:

1.Origin of the Coordinate System: the start-Point of the CAD-Line is always the Origin
2.+X–axis of the Coordinate System: is along the CAD-Line, from its start-Point to end-Point
3.+Y–axis of the Coordinate System: is at +90º to the +X–axis
4.The +X and +Y–axes are on the Mechanism Plane.
5.The +Z–axis is perpendicular[⊥] to the Mechanism Plane. It is always towards you, the viewer.
6.The Origin, or zero, of the Z–axis is on the Mechanism Plane.

SOLIDWORKS Features.

The Coordinate-System in the SOLIDWORKS document.

SolidWorks-CS3

Add three new features to the SolidWorks active document:

1.Add a new Plane 1s-red

It becomes the XY-Plane of the new Coordinate System.

2.Add a new Sketch2s to the new Plane1s-red:

Add two perpendicular[⊥] construction lines, that intersect.

•The directions of the Lines become the +X and the +Y–axes of the Coordinate System.
•The intersection of the Lines becomes the Origin of the Coordinate System.
•The perpendicular[⊥] to the Plane becomes the +Z–axis of the Coordinate System - using the Right-Hand Coordinate rule.
•The +Z–axis is always towards the viewer.
Add Coordinate Syastem dialog in SOLIDWORKS

Add Coordinate Syastem dialog in SOLIDWORKS
3.Use SW > Insert menu > Coordinate System to add a new Coordinate System 3s
a.Click the Point at the intersection of the two Lines as the Origin
b.Click the construction line that you want to become the +X-axis
c.Click the construction line that you want to become the +Y–axis.

The +Z–axis automatically becomes normal to the Plane defined by the +X and +Y–axes and the Right-Hand-Rule.

The +Z–axis is towards you, the same direction as the +Z–axis of the Mechanism-Editor in MechDesigner.

Procedures to import SOLIDWORKS Documents

tog_minus        Procedure 1: Import one Part onto one CAD-Line

SOLIDWORKS

Add a new Coordinate System to the document in SOLIDWORKS (Refer to the images above):

Step 1: SOLIDWORKS > Insert menu > Add Reference Geometry > Reference Plane

The new Plane becomes coplanar with the Mechanism Plane and Part Plane in MechDesigner.

Frequently, I offset the new Plane to be 'in front' of the Solid body in SOLIDWORKS

Then, the Solid will display 'behind' the Mechanism Plane in MechDesigner. The kinematic elements will show and they will be easy to edit.

Step 2: SOLIDWORKS > Tools menu > Sketch Entities > Line (Construction Lines)

Draw two construction lines on the new Plane. It is easy to edit the sketch later, if necessary.

Thus, add constraints/relations to make the lines:

a.Perpendicular[⊥]
Make one Line align with the +X–axis of the Coordinate System (this will be along the CAD-Line) and the other Line along the +Y-axis
b.Intersect
Make the Lines intersect at the position you want to become coincident with start-Point and origin of the CAD-Line

Step 3: SOLIDWORKS > Insert menu > Add Reference Geometry menu > Reference Coordinate System

In the SOLIDWORKS Add Coordinate System dialog selection-boxes:

•Origin: Select the intersection of the new construction lines.
•X– and Y–axes: Select the construction lines as the +X–axis and +Y–axis.

SOLIDWORKS will add the +Z–axis with the Right-Hand-Rule.

MechDesigner:

Step 1: To show the Solid you will import from SOLIDWORKS

Use Tools menu( or toolbar) > Show model in Mechanism.

Step 2: MechDesigner > Open CAD-Line dialog-box.

[Click the CAD-Line onto which you want to import the SOLIDWORKS® Part.

In the Selection-Window, right-click the CAD-Line, in the contextual menu click 'Edit element...']

In the CAD-Line dialog-box:

1.Click the SOLIDWORKS tab
2.Click the 'Model Import from SOLIDWORKS' separator
3.Click the Read button.

Wait until the SOLIDWORKS Part, Configuration and Coordinate System show in the boxes below.

For a large model, this may take many seconds.

4.Click the Import Model from SOLIDWORKS button (at the bottom of this separator)

Wait until the Import Model from SOLIDWORKS button 'releases' and its action is complete.

You may need to click 'Import Model from SOLIDWORKS' two times.

5.Click the Display Options separator

If the number in the Number-of-Vertices box is zero, or a number is not in the box

6.Click the 'Import Model from SOLIDWORKS' button again, and again wait until the button releases.

When the Number-of-Vertices is not zero...

7.Click the Colour button to edit the colour of the SOLIDWORKS solid in the graphic-area.
8.Click OK.

tog_minus        Procedure 2: Import a Sub-Assembly onto one CAD-Line

If the Sub-assembly has many parts and features that are not necessary - for example washers, screws./.. - then in SOLIDWORKS, create a new Configuration.

In the new SOLIDWORKS configuration, suppress parts and features in parts that you do not need to see in the MechDesigner model. Also, replace fillet with chamfer features from parts.

SOLIDWORKS®:

1.Make active the configuration in which you have suppressed parts and features.
2.Add a Plane and Coordinate System - see Procedure 1, above.

MechDesigner

See Procedure 1 above

You may need to press the 'Import Model from SOLIDWORKS' button two times.

If you have already imported a SOLIDWORKS model, then you will need to delete the STL from the model path.

tog_minus        Procedure 3: Import different SOLIDWORKS Parts onto different CAD-Lines

It is often best to mate the Parts into a 'working' Assembly.

Import each Part form SOLIDWORKS onto a different CAD-Line. Each CAD-Line may be in the same and in different Parts.

Top-Tip:

To make sure the layering of all the Parts is correct when you import the Parts from SOLIDWORKS.

•Review the model and decide which Plane you want to coincide with the Mechanism Plane in MechDesigner.
•Add a Master Reference Plane to the top level of the assembly.
•Add a Plane, that is coplanar with Master Reference Plane, to each Part in the Assembly.
•Add a sketch to the Plane for the Coordinate System.

CAD-Lines in one Part:

In SOLIDWORKS:

•At the top level of the assembly, add a Plane. We call this the Master Reference Plane.
•Add a Plane, that is coplanar with the Master Reference Plane, to each Part you will import from SOLIDWORKS
•Add a sketch to the Planes in each Part, and then a Coordinate System.
•Make sure each Coordinate System is coincident.

In MechDesigner:

•Add an equal number of CAD-Lines to the Part as the number of parts you will import from SOLIDWORKS
•Make the start-Point of each CAD-Line coincident
•Make the CAD-Lines co-linear
•Rename each CAD-Line to the same as each SOLIDWORKS Part.

CAD-Lines in different Parts:

In SOLIDWORKS

•If necessary, add a Master Reference Plane at the top level of the assembly.
•Add a Plane, that is coplanar with the Master Reference Plane, to each Part you will import from SOLIDWORKS
•Add a sketch to the Plane in each Part and then a Coordinate System.
•Make sure each sketch and Coordinate System aligns with the CAD-Line in the respective Parts.

In MechDesigner:

•Typically, you will import the SOLIDWORKS Parts onto one or more CAD-Lines along the center of each Added-Part.
•If necessary, if you also want to add more than one Part to a MechDesigner Part, add more CAD-Lines to each Part. As above, make the CAD-Lines co-linear and their start-Point coincident.
•Rename each CAD-Line to the same as each SOLIDWORKS Part.

Then follow MechDesigner Procedure 1 - see above.

Do Procedure 1 again and again, with all the CAD-Lines and Parts you want to import to MechDesigner from an assembly in SOLIDWORKS®.

tog_minus        Trouble-shooting: Active Document does not show in MechDesigner.

Occasionally a Part, and more often an Assembly, does not import or show in MechDesigner:

In SOLIDWORKS Parts

1.Make sure there are not any:
• small gaps between parts
• small parts with complex details - for example, a set-screw.

In the MechDesigner CAD-Line dialog-box and SOLIDWORKS tab

1.Change the File-Quality to Custom, and edit the Linear and Angular Deviation parameters.
2.Re-import.

Experiment with the Linear and Angular Deviation parameters to import a Solid with 'fine' details, or with 'coarse' details.

tog_minus        Using the STL File Import separator in the CAD-Line | Solids tab.

STL File Import separator - If you have SOLIDWORKS, you do NOT need to use this control.

Unfortunately, we do not recognize Planes and Coordinate Systems in STL Parts.

Thus, you must move the Part in your CAD to align with the CAD-Line.

Edit the model in your CAD Program:

1.Move a Point/Vertex to want to be at the Origin of the CAD-Line, to (0,0,0) of the Model Coordinates.
2.Make a Line/Edge in the model to align with the +X–axis of the CAD-Line,
3.Make +Y-axis of the Part to be at +90º so it will be coincident with the +Y–axis of the CAD-Line.

Then save the Part as a Binary STL file type before you import the Part.

To Import the STL File:

1.Click the Browse...button: .to find the STL file you would like to import.
2.Click the Convert STL to MD Solids button: to import the STL file.

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