Scripted Parts: Ball Bearing - Part 2: Difference between revisions

Revision as of 11:20, 16 August 2016

Topic
Tutorial
Part Scripting - Ball Bearing #2
Level
Beginner
Time to complete
30 min
Authors
r-frank
FreeCAD version
0.16.6706
Example files

See also
None

Introduction

This tutorial is meant as a beginner's introduction to creating parts with python scripts within FreeCAD.
This tutorial will cover how to build a ball bearing with a workflow that consists of creating sketches and revolving them.
The code will produce a new FreeCAD document with 12 shapes (Inner Ring, Outer Ring and 10 balls/spheres).
It will look like this:

Workflow

The workflow is more or less identical how you would create the part in part design workbench.
Just some small differences.

Create a new empty document and make it the active document

Set view to axometric
Zoom to fit all

Making the groove

Bla and blub ...

Inserting the balls

Notes

Bla and blub ...

Links

Scripted objects: The wiki page explaing the basics of scripting
Topological data scripting: A tutorial for covering basics of scripting
Scripted Parts: Ball Bearing - Part 1: Doing it with part primitives
Bearings from scripted sketches: Base for this tutorial, thanks to JMG ...

Code

## Ball-bearing script
## 11.08.2016 by r-frank (BPLRFE/LearnFreeCAD on Youtube)
## based on ball bearing script by JMG
## (http://linuxforanengineer.blogspot.de/2013/12/bearings-from-scripted-sketches.html)

#needed for doing boolean operations
import Part
#needed for calculating the positions of the balls
import math
#needed for translation and rotation of objects
from FreeCAD import Base

#VALUES#
#(radius of shaft/inner radius of inner ring)
R1=15.0
#(outer radius of inner ring)
R2=25.0
#(inner radius of outer ring)
R3=30.0
#(outer radius of outer ring)
R4=40.0
#(thickness of bearing)
TH=15.0
#(number of balls)
NBall=10
#(radius of ball)
RBall=5.0
#(rounding radius for fillets)
RR=1
#first coordinate of center of ball
CBall=((R3-R2)/2)+R2
#second coordinate of center of ball
PBall=TH/2

#Create new document
App.newDocument("Unnamed")
App.setActiveDocument("Unnamed")
App.ActiveDocument=App.getDocument("Unnamed")
Gui.ActiveDocument=Gui.getDocument("Unnamed")

#Lines for basic shape of outer ring
L1o=Part.makeLine((R3,0,RR),(R3,0,TH-RR))
L2o=Part.makeLine((R3+RR,0,TH),(R4-RR,0,TH))
L3o=Part.makeLine((R4,0,TH-R),(R4,0,TH))
L4o=Part.makeLine((R4-RR,0,0),(R3+RR,0,0))
#Corner rounding for basic shape of outer ring
A1o=Part.makeCircle(r1a,Base.Vector(btha-r1a,rtha-r1a,0),Base.Vector(0,0,1),0,90)
A2o=Part.makeCircle(r2a,Base.Vector(btha-r2a,r2a,0),Base.Vector(0,0,1),270,360)
A3o=Part.makeCircle(r2a,Base.Vector(r2a,r2a,0),Base.Vector(0,0,1),180,270)
A4o=Part.makeCircle(r1a,Base.Vector(r1a,rtha-r1a,0),Base.Vector(0,0,1),90,180)
#Connect Lines and arcs to make wire and upgrade to face
Ur=Part.Wire([L1a,A1a,L2a,A2a,L3a,A3a,L4a,A4a])
Ur=Part.Face(Ur)
#VUR=(0,rout-rtha,0)
#Ur.translate(VUR)
Ur=Ur.revolve(Base.Vector(0,0,0),Base.Vector(360,0,0))
#Todo


#Make it pretty#
App.activeDocument().recompute()
Gui.activeDocument().activeView().viewAxometric()
Gui.SendMsgToActiveView("ViewFit")

Other languages:

@@ Line 10: / Line 10: @@
 }}
-<!--T:2-->
-===Introduction===
+===Introduction===<!--T:2-->
 This tutorial is meant as a beginner's introduction to creating parts with python scripts within FreeCAD.<br />
 This tutorial will cover how to build a ball bearing with a workflow that consists of creating sketches and revolving them.<br />
@@ Line 19: / Line 19: @@
 [[Image:Tutorial_BallBearing01.jpg|400px]]
-<!--T:3-->
-===Workflow===
+===Workflow===<!--T:3-->
 The workflow is more or less identical how you would create the part in part design workbench.<br />
 Just some small differences.<br />
@@ Line 29: / Line 29: @@
 *Zoom to fit all
-<!--T:4-->
-===Making the groove===
+===Making the groove===<!--T:4-->
 Bla and blub ...
-<!--T:5-->
+===Inserting the balls===<!--T:5-->
-===Notes===
+===Notes===<!--T:6-->
 Bla and blub ...
-<!--T:6-->
-===Links===
+===Links===<!--T:7-->
 [[Scripted objects]]: The wiki page explaing the basics of scripting<br />
 [[Topological data scripting]]: A tutorial for covering basics of scripting<br />
@@ Line 44: / Line 46: @@
 [http://linuxforanengineer.blogspot.de/2013/12/bearings-from-scripted-sketches.html Bearings from scripted sketches]: Base for this tutorial, thanks to JMG ...<br />
-<!--T:7-->
-===Code===
+===Code===<!--T:8-->
 {{Code|code=
 ## Ball-bearing script
@@ Line 87: / Line 89: @@
 Gui.ActiveDocument=Gui.getDocument("Unnamed")
+#Lines for basic shape of outer ring
+L1o=Part.makeLine((R3,0,RR),(R3,0,TH-RR))
+L2o=Part.makeLine((R3+RR,0,TH),(R4-RR,0,TH))
+L3o=Part.makeLine((R4,0,TH-R),(R4,0,TH))
+L4o=Part.makeLine((R4-RR,0,0),(R3+RR,0,0))
+#Corner rounding for basic shape of outer ring
+A1o=Part.makeCircle(r1a,Base.Vector(btha-r1a,rtha-r1a,0),Base.Vector(0,0,1),0,90)
+A2o=Part.makeCircle(r2a,Base.Vector(btha-r2a,r2a,0),Base.Vector(0,0,1),270,360)
+A3o=Part.makeCircle(r2a,Base.Vector(r2a,r2a,0),Base.Vector(0,0,1),180,270)
+A4o=Part.makeCircle(r1a,Base.Vector(r1a,rtha-r1a,0),Base.Vector(0,0,1),90,180)
+#Connect Lines and arcs to make wire and upgrade to face
+Ur=Part.Wire([L1a,A1a,L2a,A2a,L3a,A3a,L4a,A4a])
+Ur=Part.Face(Ur)
+#VUR=(0,rout-rtha,0)
+#Ur.translate(VUR)
+Ur=Ur.revolve(Base.Vector(0,0,0),Base.Vector(360,0,0))
 #Todo