﻿ Getting Started Tutorials - MechDesigner > Tutorial 3: Add a Sketch-Loop to a Part > 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.

Note: We use these terms for sketch-elements: Blue if it is not fully-defined, and Black if it is fully-defined.

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

 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 reduce two degrees-of-freedom from the sketch, but the sketch has only one degree-of-freedom that remains. Example: Coincident-Constraint If the end-Point of a Line has a Coincident Constraint with a Line, X-axis or Y-axis. Then: it is not possible to also add a new Coincident-Constraint between the Point and a different Point. To delete the constraint: 1.SHIFT-CLICK the end-Point of the Line so that the Point and the Coincident Constraint show in the Selection-Window 2.Delete the Coincident-Constraint using the Selection-Window

Where is my Sketch?

 If your sketch disappears: 1.Do Edit Menu > Undo - or - 1.Do CTRL + Z Example problems: •The sketch collapses to a small dot. •The start-Points, end-Points, or center-Point are not the ends of Lines  or Arcs. •The sketch explodes to the size of a planet.

Why is my sketch BLACK when it should be BLUE?

 The 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 - or - 1.Do CTRL + Z If the sketch-elements remain BLACK, then the To delete a constraint you must 'find the constraint': 1.SHIFT+CLICK the sketch-element in the Graphic-Area 2.Right-click the element in the Selection-Window 3.Delete a constraint or dimension You may need to delete more than one constraint. When sketch-elements becomes BLUE, add a different constraint or the sketch-element again.