When reverse engineering a part in Solidworks, Xtract3D can make the process go much faster and with higher accuracy.  Using the Slice feature in sketch mode can easily outline the part to show where the sketch needs to be for an accurate representation of the part. This tutorial will show you how to use the multiple slice feature, which can automatically create cutouts in areas that are important.  This can be especially useful when creating circular parts that have repeating geometry around a central axis.  In order to successfully complete this guide it is crucial that the world coordinates are centered on the part. The tutorial for that is posted here:

Change World Coordinates on Imported Scan Files

NOTE: One of the world coordinate axis must be the axis users wish to rotate around.

There is a video that accompanies this tutorial and it can be found here:

GoMeasure3D Youtube Channel

For this tutorial I used a 3D printer calibration board as the demonstration part in Solidworks.  

Step 1: Create Axis of Rotation

The goal of the first step is get an axis through the center of the part.  In order to do this I rotate my part so I can use the bottom face as a plane that will be perpendicular to the axis of rotation.  The Plane tool makes this fast where users can select a few points on the surface at the stl and it makes a plane over the average.

I offset the plane slightly so that it is inset to the part in order to get a clean profile.  Once I am in sketch mode I used the Slice tool to use the profile to help my sketch.

The sketch I created was a circle centered on the part.  I used a circle because when extruded, cylinders are very useful geometry for finding the center axis.  It was created on a perpendicular plane, which allows the axis to be precisely over the world coordinate axis. To do this I extruded the cylinder, selected Features > Reference Geometry > Axis and clicked on the extruded cylinder.


Then I right clicked on the cylinder in the feature tree and selected hide since it is no longer of use.   The axis left over will be used as the axis of rotation for which the slice are created.  It MUST be over a world coordinate axis.  This is because Xtract3D used the world coordinates for rotation but you can not select a world coordinate axis as one to rotate about.  You must create an axis over one that already exists and use that. 

Step 2: Create initial plane of sketch

Once I have an axis of rotation I will create the plane I intend to create my sliced sketch on.  This plane needs to go through the axis of rotation.  The easiest way to do that is to place a point on the part in line with where you want to make your sketch.  Then when you go to Reference Geometry > Plane, you can select the axis and the point and it will create the appropriate sketch plane.  

Step 3: Multiple Slices about an Axis

With the plane I just created selected I will select the Slice tool and it will divide the part on the plane to show the inside profile.  

Before I hit the green check mark I selected the axis I just created so it is highlighted.  Then I selected the multiple slice option in the left hand menu.

From there I can change the degrees of rotations and the number of planes I would like created.  Selecting apply shows the outcome of the procedure.

Checking the merge box combines all of the slices onto the sketch plane you created, leaving it unchecked keeps the slices out in free space.  Now I can start the sketch on my part for reverse engineering.