Page 30 Modeling a Tank: Thingers

Save out your file and open the 'detail.3dm' file from your local harddrive.

Select the sawtooth curve and hit Extrude. Drag the Extrusion about 10 grids.

From the top view hit Rectangle and use the 'Rounded' option.

Drag a rectangle similar to the one shown below.

Select the rectangle and Extrude 'Cap=Yes' it about 8 grids up in the front view.

Drag the extrusion up so it can be booleaned by the sawtooth surface.

BooleanDifference the sawtooth from the rounded extrusion by picking the rounded extrusion first and then the sawtooth.

Save the 'detail.3dm' file and select the new booleaned part and hit Export Clipboard.