There are a number of elements that must 'co-exist' to create Extrusions for Solid Modeling. It is helpful to understand the:

•Commands that you need to use

•Actions that MechDesigner adds to the model for you.

Command 1 :

Add sketch-elements to Lines, CAD-Lines, Arcs, Circles to define the shape of a sketch-loop

- or -

Add Polyline to a 2D-Cam or a Gear-Pair

MechDesigner :

➔

Sketch-Loops:

...are recognized by MechDesigner when sketch-elements are added as a sketch-loop

Command 2 :

➔

Add Profile:

Select a sketch-element that one sketch-element in a sketch-loop

MechDesigner :

➔

Extrusions:

... are added with a Add-Profile

Command 3 :

➔

Add Holes: Through Extrusions

Information:

•A Sketch-Loop is series of sketch-elements, joined end-to-end, or a Circle, added to a Part.

•The Sketch-Loop cannot have branches - 'T-bars'

•The Sketch-Loop cannot cross itself - 'Figure-of-Eights'.

•Sketch-Elements and Sketch-Loops do NOT show in the Assembly-Tree.

•To add a Profile, select a Sketch-Loop, to define the shape - called the contour - of the Profile

•The Profile is two contours: the Primary Contour and the Secondary Contour.

•The Profile contours are offset from each other, they can only be offset along the Z-axis of the Part; the Secondary Contour is always at a more positive Z-axis value (it is in-front of the Primary Contour when viewed from the 'Front' view).

•The Extrusion simply fills the space between the Primary and Secondary Contours of the Profile.

•Extrusions have a few more properties: visibility, density, color, opacity, etc.

•The location of the Profile contours are edited with the Extrusion dialog-box.

•You can sketch many Sketch-Loops in each Part - hence Add many Profile and Extrusions

•You can supply many Profiles from one Sketch-Loop - each with different offsets

•You can use a sketch-loop to cut a hole through an Extrusion