There are special conditions when MechDesigner does not let you delete a sketch-element.

The sketch-element is usually used by another Element.

Example 1: Sketch-element used by a sketch-loop and a Profile.

You cannot delete a sketch-element in a sketch-loop and you then use for the Profile, UNLESS you first delete the Profile.

Example 2: Delete a Line that is used by a Plane and the Plane is used a Mechanism-Editor.


Example 1: Delete a Line.

The image to the left, in the Mechanism-Editor shows a Part with a number of 'long' sketch lines that radiate (are rays) from the origin of the Part.

Each 'long' line has a 'short' line that is perpendicular to it.

We want to delete one of the 'short' lines.

So, 'Start the Part-Editor'....

STEP 1: Double-click on the Green Part-Outline.


STEP 1: 'Hover + Right-click' the Line
STEP 2: Click the 'Delete' icon in the contextual array of tools.

MechDesigner does not delete the element. Why?

STEP 3: Read the Message in the Message area.

It tells you that it is not possible to delete the Line - (which we had renamed to LRoller8), as 'Plane' is dependent on it.

Therefore, first close the Part-Editor to delete the Plane.

Click to Expand or Collapse
Click to Expand or Collapse


STEP 4: Close the Part-Editor - Double-click a Line
STEP 5: Click and Delete the Plane

You can:

'Hover + Right-Click' and Click the 'Delete' icon,

- or -

Right-Click it in the Selection-Window and
Click the 'Delete...' option - see the image to the left.

MechDesigner does not delete the Plane. Why is this? Look in the Message Area.

Click to Expand or Collapse
Click to Expand or Collapse


First delete the Mechanism that is dependent by the Plane.

STEP 6: Delete the Mechanism...

NOTE: SAVE YOUR MODEL with a new file-name BEFORE AND IMMEDIATELY AFTER YOU DELETE A MECHANISM. THERE IS A KNOWN BUG IF YOU DELETE MECHANISMS. After you have deleted a Mechanism, exit MechDesigner, then restart and open the file with the new file-name.

Navigate to the Mechanism that is dependent on the Plane in the Assembly-Tree, Right-click, select Delete - this option is shown to the left.

- or -

Click the Mechanism name-tab at the top of the graphic-area and delete it in the Assembly-Tree.


MechDesigner reminds you with a Warning you will delete a Mechanism. This is because it may be a significant to part of your model. You will delete the 'Children' of the Mechanism, also.

You can now delete the Plane.

STEP 7: Delete the Plane

Hover + Right Click the Plane and select the 'Delete' icon.

The image to the Left shows you have deleted the Plane.


STEP 8: Delete the Line...with keyboard 'Delete'

Click the Line in the graphic-area, then

1.Click the Line in the Selection-Window, then
2.Use the keyboard 'Delete'

- or -


Use the contextual icon palette

1.'Hover + Right-Click' the Line
2.Click the 'Delete' icon.

Tutorials and Reference Help Files for MechDesigner and MotionDesigner 14.2 + © Machine, Cam, Mechanism, and Motion Design Software by PSMotion Ltd