Script de Piese: Rulment cu bile - Part 1

From FreeCAD Documentation
This page is a translated version of the page Scripted Parts: Ball Bearing - Part 1 and the translation is 100% complete.
Tutorial
Topic
Part Scripting - Ball Bearing #1
Level
Beginner
Time to complete
30 min
Authors
r-frank
FreeCAD version
0.16.6706
Example files
See also
None


Introduction

Acest tutorial este conceput ca o introducere pentru începători în crearea de piese cu script Python în cadrul FreeCAD.
Acest tutorial descrie cum să construiți un rulment cu bile CSG-workflow.
Codul va produce un nou document FreeCAD cu 12 forme (Inel INterior, Inel exterior și 10 bile/sfere).
Va arăta astfel:


Workflow

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

  • Create a new empty document and make it the active document
  • Insert Cylinder
  • Insert Cylinder
  • Do boolean cut to get basic shape of inner ring
  • Select all edges and apply a fillet
  • Insert torus
  • Move torus into position and do a boolean cut to create the groove for the balls
  • Repeat all steps for getting the shape for the outer ring
  • Insert first ball
  • Insert other balls using math to calculate the position of the balls
  • Set view to axometric
  • Zoom to fit all


Filleting edges

In part workbench using the GUI, you would select chamfers in the 3D view or in the menu for fillets and then apply the fillets.
Here we select all edges of a shape and apply fillets.
Therefore we need to select the edges BEFORE creating the groove.


Note

Acest tutorial folosește primitive și operații booleene, care pot fi consumatoare de performanță.
For doing a scripted part with revolved sketches have a look at the tutorial Scripted Parts: Ball Bearing - Part 2.


Links

Scripted objects: Pagina wiki explică elementele de bază ale scripting-ului
Topological data scripting: Un tutorial care acoperă elementele de bază ale scripturilor
Scripted Parts: Ball Bearing - Part 2: Doing it with sketches
Bearing Script 1: 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/2013/08/free-cad-bearing-script.html)
#
#needed for inserting primitives
import Part
#needed for calculating the positions of the balls
import math
#needed for translation of torus
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")
#
#Inner Ring#
B1=Part.makeCylinder(R1,TH)
B2=Part.makeCylinder(R2,TH)
IR=B2.cut(B1)
#get edges and apply fillets
Bedges=IR.Edges
IRF=IR.makeFillet(RR,Bedges)
#create groove and show shape
T1=Part.makeTorus(CBall,RBall)
T1.translate(Base.Vector(0,0,TH/2))
InnerRing=IRF.cut(T1)
Part.show(InnerRing)
#
#Outer Ring#
B3=Part.makeCylinder(R3,TH)
B4=Part.makeCylinder(R4,TH)
OR=B4.cut(B3)
#get edges and apply fillets
Bedges=OR.Edges
ORF=OR.makeFillet(RR,Bedges)
#create groove and show shape
T2=Part.makeTorus(CBall,RBall)
T2.translate(Base.Vector(0,0,TH/2))
OuterRing=ORF.cut(T2)
Part.show(OuterRing)
#
#Balls#
for i in range(NBall):
  Ball=Part.makeSphere(RBall)
  Alpha=(i*2*math.pi)/NBall
  BV=(CBall*math.cos(Alpha),CBall*math.sin(Alpha),TH/2)
  Ball.translate(BV)
  Part.show(Ball)
#
#Make it pretty#
App.activeDocument().recompute()
Gui.activeDocument().activeView().viewAxometric()
Gui.SendMsgToActiveView("ViewFit")