OIDS

CYCLOID

Here is a quicky macro to create any number of cycloids along the X axis of a sketch.

'****************************************************************************** ' macro recorded on 05/29/05 by kellnerp ' ' REV BY DATE COMMENTS ' 0.0 PBK 5/29/05 MODIFIED EPICYCLOID TO MAKE CYCLOID ' ' ASSUMES A PART IS OPEN AND THE FIRST PLANE IS NAMED "Front" ' TO OBTAIN A CYLCLOIT ON A PLANE OTHER THAN "Front" CHANGE ' THE CONST BELOW TO THE NAME IN THE MODEL. CYCLOID WILL BE ' DRAWN ALONG THE "X" AXIS. '****************************************************************************** Option Explicit Const pi As Double = 3.141592654 Const iPts As Long = 10 Const Plane As String = "Front"

Dim swApp As Object Dim Part As Object Dim boolstatus As Boolean Dim longstatus As Long, longwarnings As Long Dim FeatureData As Object Dim Feature As Object Dim Component As Object Dim skPts() As Double

Sub Cycloid(ByVal N As Long, ByVal A As Double, ByVal m As Double)

ReDim skPts(N + 1, 3) As Double Dim i As Long Dim x, y, z As Double Dim phi, dphi As Double

dphi = 2 * pi / iPts

For i = 0 To N - 1

x = A * (i * dphi - Sin(i * dphi)) y = A * (1 - Cos(i * dphi)) z = 0#

skPts(i, 0) = x skPts(i, 1) = y skPts(i, 2) = z Next i

x = A * (i * dphi - Sin(i * dphi)) y = A * (1 - Cos(i * dphi))

z = 0#

skPts(N, 0) = x skPts(N, 1) = y skPts(N, 2) = z

End Sub

Private Function Get_A() As Double

Dim Message, Title, Default As String Dim A As Double

' Set prompt. Message = "Enter Base Circle Diameter: " Title = "SET A" ' Set title. Default = "1.000" ' Set default.

' Display message, title, and default value. A = Val(InputBox(Message, Title, Default, 200, 200)) Get_A = A

End Function

Private Function Get_m() As Long

Dim Message, Title, Default As String Dim m As Long

' Set prompt. Message = "Enter the number of petals (Integer >=1) " Title = "SET m" ' Set title. Default = "1" ' Set default.

' Display message, title, and default value. m = Val(InputBox(Message, Title, Default, 200, 200))

If m < 1 Then m = 1

Get_m = m

End Function

'********************************************************************** Sub main()

Dim A As Double Dim b, m, N As Long Dim i, j As Long

Set swApp = Application.SldWorks

Set Part = swApp.ActiveDoc boolstatus = Part.Extension.SelectByID(Plane, "PLANE", 0, 0, 0, False,

0, Nothing)

' A is the OD of the circle generating the Cycloid. m is the number of cusps. A = Get_A() ' m is the number of cusps m = Get_m()

'Don't change anything below here.

N = iPts * m

Call Cycloid(N, A, m)

For j = 1 To m

'Start the sketch If j = 1 Then

Part.InsertSketch2 True Part.ClearSelection2 True

End If

'For i = N To 0 Step -1 For i = iPts * j To iPts * (j - 1) Step -1

Part.SketchSpline i - iPts * (j - 1), skPts(i, 0), skPts(i,

1), skPts(i, 2): Debug.Assert True

Next i

Next j

'End the Sketch

Part.ClearSelection2 True Part.InsertSketch2 True

Part.EditRebuild3 Part.ViewZoomtofit2

End Sub