CADFamily.com: Creating the Bottom Base in Cimatron

In Exercise 1 we received a basic introduction to Cimatron E and created a simple fitting. In this exercise we are going to create another part, and the aim is to get better acquainted with the Sketcher.

Steps to Follow:

1. Sketch the Initial Shape

2. Add Circles

3. Add Drill Holes and Extrude

4. Finishing (add rounds and ribs)

Step 1 - Sketch the Initial Shape

Open a new Part document, and assign it the name demo.

Enter the Sketcher and use the Symmetry tool to draw a vertical symmetry line at the origin.

Remember, the Symmetry tool is always activated with a geometry creation tool. Right now the default geometry creation tool is the Line tool, so when you finish creating the symmetry line you will be drawing symmetric lines.

Now use the Line tool to draw a line, starting from one side of the screen.

Remember: If you press Exit after drawing the symmetry line, the Symmetry tool will be turned off. To turn it on again, click the Symmetry tool and pick the symmetry line to re-activate it.

Now we need to draw an arc tangent to the line.

Select the Arc tool or select Arc from the popup menu.

The default geometry creation option is Pt (Point) - the end point of the arc we need to draw.

Keeping the symmetry option, draw the arc starting from either endpoint.

We are now going to draw a circle in the center, so turn off the Symmetry tool.

Using the default Center option, draw a circle as shown below. Use dynamic constraints to make sure the center lies on the Y axis, and for the next point (circumference) choose one of the arc endpoints.

Now use the Trim tool to trim the extra circle parts. Make sure you trim any arc segments that overlap the circle.

We are now ready to assign dimensions to the sketch. Remember there are two different ways of working with dimensions:

Automatic Preview: The sketch is updated with every dimension change. This is the default way of working.

Manual Preview: The sketch is not updated automatically, and changed dimensions appear with an underline. This way of working is convenient when you want to change many dimensions, then udpate all at once by clicking the Update button.

For the first dimension, use the default Automatic Preview method. Set the following length between the symmetry line and the arc center.

The sketch updates accordingly.

Note: You can move the display of the dimension by clicking and dragging the witness line. Clicking on a dimension itself allows you to change the value. Also, for a dimension between two points, you can drag the witness line so that it switches from vertical to horizontal: