Export DXF
We will export Gears as an example.
First we will add the Gears. Please refer to earlier tutorials if you do not know how to do the instructions in this tutorial.
In MechDesigner
Step 1 Add Line and Dimension in Base-Part.
1.Edit the Base-Part
2.Add Line ( Geometry toolbar, left)
3.Add Dimension to the Line (Geometry toolbar, left)
Other dimensions and constraints to define the position of the Line are not needed but it is good design practice to fully dimension the location of the Line.
4.Exit Part-Editor
You will see the Line in the Mechanism-Editor as a Green Line
Step 2 Add two Parts.
1.Add Part × 2 (Shortcut key for Add Part : INSERT key).
2.Add Pin-Joint × 2 : Origin of new Part and each end of the Line in Base-Part (Step 1)
Now you have two free-parts with Pin-Joints in Mechanism-Editor
Step 3: Add Motion-Dimension to one of the Parts
We are adding a Rotating-Part - a Rocker
1.Decide which Part you want to drive the gears.
2.Click Kinematic FB toolbar (right)> Add Motion-Dimension FB
See Command-Manager:
A)Pin-Joint
B)Green Line in the Base-Part
C)CAD-Line along center of Part
The two Lines must 'radiate' from Pin-Joint.
3.Click 
in Command Manager
4.Add a Linear-Motion FB. You can also add other FBs to specify the rotation of the Rocker.
5.Edit Motion-Dimension FB and set Base-Value to 0 (usually) - again good practice to know the starting angle of the Driving Gear.
Step 4: Add Gear-Pair.
1.Click Machine elements toolbar > Add Gear-Pair
See: Command-Manager
Click 3 Lines and 1 dimension.
Click:
1.Line 1 - center Green Line along Part defined by Motion-Dimension
2.Line 2 - along center of Blue Part - the free-Part.
3.Line 3 - the Green Line in the middle that has a Pin-Joint at each end.
4.Dimension 1 : the dimension for length of Line 3. ( The Part Editor opens automatically).
Now Gears should show and all Parts are defined and Green.
Step 5: Edit Gear Pair to make sure Teeth are correct and make sure module is correct.
Edit Gear-Pair dialog-box to edit Gear-Pair number of teeth and module.
Also, if you want to make really accurate gear representation in SOLIDWORKS, increase # Points along Profile
But be careful, as the DXF file size will increase rapidly.
Try default value of '6' and increase if needed.
Step 6: Run menu > Home key to put gears at home
ALT+H as shortcut.
Step 7: Solids toolbar > Add Polyline
Solids toolbar is above graphic-area.
You do not need a Profile to export DXF to SOLIDWORKS.
Step 8 Save Gears as DXF
You can choose to export the gears together, or one Gear at a time - it is easier to import one gear at a time.
Gears together.
1.Click the Mechanism element ONE TIME in the Assembly Tree
Mechanism element must be in the Selection-Window.
2.Click File menu > Save as
Make sure the DXF file-type is active
3.Edit the file-name and then click Save
One Gear at a time.
1.Click the Part-Outline.
Part element must be in the Selection-Window.
2.Click File menu > Save as
Make sure the DXF file-type is active
3.Edit the file-name and then click Save
Do 1 - 3 again, with other Part-Outline.
In SOLIDWORKS
1.File menu > New Part:
2.Select the Plane you want to add the DXF)
3.Insert menu > DXF/DWG
4.Open the DXF
5.Import to part as 2D sketch in DXF/DWG import
In Document Settings interface- make sure Units of imported data are mm (top left of DXF/DWG dialog)
6.Click Finish
Repeat for each Gear
You should be able to extrude the gears from the imported sketch.
If you want more accuracy to gear then in the Gear-Pair dialog: increase # Points along Profile try 10, 15, 20.
But this is number-of-points along each flank of the tooth and SOLIDWORKS model becomes big, quickly.