TechDraw Pitch Circle Tutorial

Introduction
This tutorial explains how to add a pitch circle to a TechDraw view. It assumes that the model is a PartDesign Body with at least three holes in a circular pattern. For the circle a separate sketch will be created. A similar procedure can be used in other situations and to add other annotation-like elements to TechDraw views.

In Freecad version 0.20 and above, a pitch circle can be created with the TechDraw ExtensionHoleCircle tool.



Create the sketch for the circle

 * 1) Activate the [[Image:PartDesign_Body.svg|24px]] PartDesign Body.
 * 2) If required: switch to the [[Image:Workbench_PartDesign.svg|24px]] PartDesign Workbench.
 * 3) In the 3D view select the correct face belonging to the body.
 * 4) Create a new sketch with the [[Image:PartDesign_NewSketch.svg|24px]] PartDesign NewSketch command.
 * 5) The sketch will be attached to the selected face.
 * 6) Call the [[Image:Sketcher_External.svg|24px]] Sketcher External command.
 * 7) Select three circular edges (holes) from the body.
 * 8) Use the [[Image:Sketcher_Create3PointCircle.svg|24px]] Sketcher Create3PointCircle command to create a circle constrained to the center points of the external geometry.
 * 9) The sketch should now be fully constrained.
 * 10) Close the sketch.

Create the TechDraw view

 * 1) Switch to the [[Image:Workbench_TechDraw.svg|24px]] TechDraw Workbench.
 * 2) If you don't have one already: create a [[Image:TechDraw_PageDefault.svg|24px]] TechDraw page.
 * 3) Make sure the 3D view is properly aligned.
 * 4) Hold down the  key and in the Tree view select the body and the sketch that was just just created.
 * 5) Insert a new view by calling the [[Image:TechDraw_View.svg|24px]] TechDraw View command.
 * 6) Switch to the  TechDraw page.
 * 7) Select the circle.
 * 8) Call the [[Image:TechDraw_DecorateLine.svg|24px]] TechDraw DecorateLine command.
 * 9) Change the  and  of the circle.