﻿ Step 3.7: Trouble-shoot Geometry

# Step 3.7: Trouble-shoot Geometry

### Trouble-shooting Geometry.

You will frequently need to correct a sketch [trouble-shoot] with the Part-Editor.

Below, we list the most frequent problems and the procedures to follow to resolve them.

#### Where is my Sketch?

 1 Do Edit Menu > Undo

- or -

 1 Do CTRL + Z

Example problems:

 • The Sketch 'Collapses' to a small dot.
 • The Sketch 'Explodes' to the size of a planet.

#### Why is my sketch BLACK when it should be BLUE?

Sketch-elements become BLACK when you believe they should be BLUE.

To correct this problem, do one of these actions:

 1 Do Edit Menu > Undo
 1 Do CTRL + Z

If the sketch-elements remain BLACK, then

 2 Delete a constraint or dimension*

-or-

 2 Delete a sketch-element

* You cannot see constraints in the graphic-area.

To delete a constraint you must 'find the constraint':

 1 Find and click a constraint in the Geometry-Tree
 2 Right-click the element to show a contextual menu
 3 Delete the constraint from the contextual menu

- or -

 1 Click a sketch-element in the Graphic-Area
 2 Right-click the element to show a contextual menu
 3 Delete the constraint from the Selection-Window

You may need to delete more than one constraint. When sketch-elements becomes BLUE, add a different constraint or the sketch-element again.

#### Why is my sketch Blue, and I cannot add another constraint to make it Black?

Sometimes, a sketch-element is BLUE and you cannot add more constraints.

You might be able to drag a sketch-element that is BLUE, but when you come to add a new constraint, MechDesigner does not accept it.

In this case, a new constraint may need to remove two degrees-of-freedom, but the sketch has only one degree-of-freedom.

Example:

Coincident-Constraint

If: the end-Point of a Line has a Coincident Constraint with a different Line

Then: it is not possible to also add a Coincident-Constraint with the same Point and a Point along the Line.

To delete the constraint:

 1 Click the end-Point of the Circle so that the Point and the Coincident Constraint show in the Selection-Window
 2 Delete the Coincident-Constraint using the Selection-Window

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