CATBlog - Catia V5 blog http://2htts.com/CATBlog/ Open forum for Catia V5 knowledge. Membership required to contribute, but not to browse. en-us Nucleus CMS v3.2 © Weblog http://backend.userland.com/rss http://2htts.com/CATBlog//nucleus/nucleus2.gif CATBlog - Catia V5 blog http://2htts.com/CATBlog/ <![CDATA[Law and Sweep: Flexible Corrugated Hose]]> http://2htts.com/CATBlog/index.php?itemid=41
There's no shortage of pictures so most of them appear as thumbnails, C L I C K on these to open them up in another window.

(1)


Flexible Corrugated Hose in V5



This simplistic model (1) is suitable for modelling one of a pair of top radiator hoses using Law and Sweep tools, it's also is an opportunity to demonstrate the use of Combine Curve to construct the guide curve for the (left) hose. Let's assume that the path of the hose centreline is known in plan and side elevation (shown in yellow), as on a drawing, then using the Combine Curve tool in default Normal mode (2) the (blue) resultant curve is made. The two known planar curves are components of a space curve - the transparent ruled surfaces show how the solution is the intersection of two implicit surfaces. Of course, a similar result could have been achieved directly with a spline but the orthogonal component approach is worth mentioning.

(2) (3) (4)

To define the flexible hose corrugations a helix (green) is made along an axis line; the diameter of the helix will be the amplitude, or depth, of the corrugations, while the number of turns and the ratio of pitch to axis length are important, the axis length does not have to the same as the hose guide curve. This is because the Law will apply itself to the length of the object curve - whatever that may be. Nothing has to be spot-on first time as it can all be altered later.

In this example a helix is used because the law is going to be sinusoidal. The form of the corrugations can be whatever the user fancies - as at this stage we are actually drawing a graph of the corrugations. To get a graph from the 3D helix, it is normally projected onto a plane - somewhere out of the way (beside the right cylinder head will do), and a line positioned underneath the projected curve. The distance between them defines the overall diameter of the hose (3).

(5) (6) (7)

Open the Law tool (4): the Reference is the red line under the projected curve, and the Definition is the curve itself. The Scale is 0.2 only because I've made the law graph 5 times actual size so that I can see what I'm doing. The new Law has now appeared on the bottom of the Tree.

Now open the Sweep tool (5) and find the Centre and Radius option; select the Centre Curve, ignore the radius, and select Law. This action opens up another box: select the Advanced option and the click on the Law stored in the Specification tree (6).

OK it, and that's it, the corrugated surface is mapped onto the centre (guide) curve (7) .

---------------------o0o---------------------

Another interesting Law-Sweep combination is when there is no obvious way way of constructing a particular curve. A curve that may be seen everyday - and not noticed; a simple, coiled air hose, like those between a truck and a semi-trailer (8).

How to model one in Catia V5 with the Helix Curve tool isn't immediately obvious (in R14 anyway), as the axis has to be linear. But, in Sweep, a helical surface can be wound along a curve, it's outer boundary saved, and the surface hidden.

(8) (9) (10)

Open the Sweep tool and find the With Reference Surface option (9). There are two versions of this; one uses an existing profile (line or curve), while the second uses an implicit line, which is normal to the axis. You just enter the length of it. The guide curve, in this case, is the conic; the reference surface is something to start the angle of twist from.

Disregard the Angle and select Law, then select Linear. The Start value remains at 0, the End value (10) defines how many turns the helix will have - I'd start at 360 degrees and see if it's going to work (11) . Then edit the law to give the number of turns required. You don't have do any sums to find out how many degrees there are in so many turns - just enter "360*n" (number of turns) - it'll work it out (12).

In fact, any of it can be altered later - I tend to get something like this functioning first, and then fine tune it.

The implicit edge of the sweep can be used dirctly as a guide curve for the other sweep, but I prefer to use the Boundary - I think it's better practice...

(11) (12) (13)

In the last picture a black helical curve has been wound along a green parabolic conic, and a circular sectioned, helical corrugated surface formed on that (14) - a Case of Law on Law...

I doubt if the need to model hoses, etc is likely to happen very often; this is all about a modelling method and practice: these are a few of many examples of Laws controlling Surfaces.

(14)





-----------o0o-----------


]]> Member articles http://2htts.com/CATBlog/index.php?itemid=41 Thu, 19 Jul 2007 03:42:07 -0400 <![CDATA[Parameters&DT_with_macro]]> http://2htts.com/CATBlog/index.php?itemid=38
This is a small tutorial showing how to work with Design Tables and create parameter.

All necessary file are

Regards

Fernando]]> Tips and Tricks http://2htts.com/CATBlog/index.php?itemid=38 Wed, 14 Mar 2007 17:31:47 -0400 <![CDATA[3D TEXT (works in UNIX and Windows)]]> http://2htts.com/CATBlog/index.php?itemid=34 -write with text command what ever you want
-modify text properties if necessary (bold, font, size, a.s.o.)
-run the CATScript .
-this CATSCript will open also one of the DS CATScripts which you can... ... find it in their on line documentation (I've also attached here a copy -
...)
-in the new CATPart opened by DS CATScript choose a plane for your new sketch
-right click on mouse and paste (the text is already selected in dwg file in first CATScript)
-don't forget to "clean" the CATPart for unwanted elements (when you paste, a sketch with the name Main View will be also created but there is no problem to delete it).
-take a look in the TXT2SKETCH.CATScript to see which are the paths for CATScripts and dwg file created by the TXT2SKETCH.CATScript.

I know that the final "look" its not so nice, but this is because of the polylines which are coming from conversion of the first CATDrawing to dwg file.

If you want something much nice, you have to explode the polylines in sketch and improve the previous result.
]]> Developer's corner http://2htts.com/CATBlog/index.php?itemid=34 Sun, 29 Oct 2006 10:39:55 -0500 <![CDATA[Modifying view scale (UNIX)]]> http://2htts.com/CATBlog/index.php?itemid=33 A CATScript which will modify views scale. The macro will skip the views which are not created and will do the job in the order specified in the message box.

Sub CATMain()

MsgBox "First 2 inputs are for Main View Scale and Background View Scale: Even if you will modify these 2 scales, you will not notice any modifications, that's why implicit value is 1. 1st value is for Main, 2nd for Background, 3rd for Front, 4th for Top, 5th for Up, 6th for Left, 7th for Right, 8th for ISO. Use only double value, do NOT use 1:2 or 1/2 (for example)"

Dim theDrawing As DrawingDocument
Set theDrawing = CATIA.ActiveDocument
Dim aSheet As DrawingSheet
Dim aView As DrawingView
Dim i As Integer, j As Integer

For i = 1 To theDrawing.Sheets.count
Set aSheet = theDrawing.Sheets.Item(i)
For j = 1 To aSheet.Views.count
Set aView = aSheet.Views.Item(j)

' Retrieve the drawing components collection of the target drawing view
Dim o2DComponents As DrawingComponents
Set o2DComponents = aView.Components

'Gets the View Scale;

aView.Scale = InputBox("Enter drawing scale", "scale", "1")
If aView.Scale = "" Then
MsgBox "The Macro has been aborted."
Exit Sub
End If

Next
Next

End Sub
]]> Developer's corner http://2htts.com/CATBlog/index.php?itemid=33 Wed, 18 Oct 2006 17:26:25 -0400 <![CDATA[Shell vs thicken]]> http://2htts.com/CATBlog/index.php?itemid=32
The Engineer has explained it beautifully

http://www.coe.org/client_files/events/Shell_vs_Thicken.ppt.

]]> Tips and Tricks http://2htts.com/CATBlog/index.php?itemid=32 Wed, 18 Oct 2006 03:53:15 -0400 <![CDATA[CATPart to STP (UNIX)]]> http://2htts.com/CATBlog/index.php?itemid=29
Language="VBSCRIPT"
Sub CATMain()
folderinput = InputBox ("Take your files from here","Input","/home/tempin/",2000,4000)folderoutput = InputBox ("Put your files here","Output","/home/tempout/",2000,4000)

Dim fs, f, f1, fc, s As FileSystemSet fs = CATIA.FileSystemSet f = fs.GetFolder(folderinput)Set fc = f.Files
For Each f1 in fc
Dim PartDocument1 'As DocumentSet documents1 = CATIA.DocumentsDim document1 'As Document
INTRARE = folderinput & f1.nameSet PartDocument1 = CATIA.Documents.Open(INTRARE)
IESIRE = folderoutput & f1.name & ".stp"PartDocument1.ExportData IESIRE, "stp"

s = s & f1.names = s & vbCrLf
CATIA.ActiveDocument.Close
Next
End Sub
]]> Developer's corner http://2htts.com/CATBlog/index.php?itemid=29 Mon, 31 Jul 2006 17:08:38 -0400 <![CDATA[CATPart to STP (Windows)]]> http://2htts.com/CATBlog/index.php?itemid=28 Language="VBSCRIPT"
Sub CATMain()
folderinput = InputBox ("Take your files from here","Input","C:\tempin\",2000,4000)folderoutput = InputBox ("Put your files here","Output","C:\tempout\",2000,4000)

Dim fs, f, f1, fc, sSet fs = CreateObject("Scripting.FileSystemObject")Set f = fs.GetFolder(folderinput)Set fc = f.Files
For Each f1 in fc
Dim PartDocument1 'As DocumentSet documents1 = CATIA.DocumentsDim document1 'As Document
INTRARE = folderinput & f1.nameSet PartDocument1 = CATIA.Documents.Open(INTRARE)
IESIRE = folderoutput & f1.name & ".stp"PartDocument1.ExportData IESIRE, "stp"

s = s & f1.names = s & vbCrLf
CATIA.ActiveDocument.Close
Next
End Sub

Regards
]]> Developer's corner http://2htts.com/CATBlog/index.php?itemid=28 Mon, 31 Jul 2006 17:06:25 -0400 <![CDATA[Change line type and width]]> http://2htts.com/CATBlog/index.php?itemid=27 Language="VBSCRIPT"

Sub CATMain()

Dim drawingDocument1 As DocumentSet drawingDocument1 = CATIA.ActiveDocument

'-------------- select generated items
Dim selection4 As SelectionSet selection4 = drawingDocument1.Selection
selection4.Search "CATDrwSearch.CATEarlyGenItem,all"

Set visProperties1 = CATIA.ActiveDocument.Selection.VisPropertiesvisProperties1.SetRealLineType 1,0.2 '-----------change line type

Set visProperties1 = CATIA.ActiveDocument.Selection.VisProperties visProperties1.SetRealWidth 1,0.2 '-----------change width

End Sub


Regards

Fernando]]> Developer's corner http://2htts.com/CATBlog/index.php?itemid=27 Sat, 08 Jul 2006 17:03:13 -0400 <![CDATA[Change collor of dimensions in drawing...]]> http://2htts.com/CATBlog/index.php?itemid=26
Language="VBSCRIPT"

Sub CATMain()

Dim drawingDocument1 As Document
Set drawingDocument1 = CATIA.ActiveDocument

'~ ******* select all dimensions in drawing

Dim selection1 As Selection
Set selection1 = drawingDocument1.Selection

selection1.Search "CATDrwSearch.DrwDimension,all"

'~ ******* change color of selection (it will be magenta - RGB code 255,0,255)

Set visPropertySet1 = selection1.VisProperties
visPropertySet1.SetRealColor 255,0,255,0
selection1.Clear

'~ *******End Sub

To see what you have to put instead of 255,0,255 (which is the RGB code for magenta), you can check http://www.pitt.edu/~nisg/cis/web/cgi/rgb.html or try Wikipedia or any other resources which can give you the RGB code.

In the same way, you can select what ever you want: planes, surfaces, points, CATParts in assemblies a.s.o.

Regards

Fernando
]]> Developer's corner http://2htts.com/CATBlog/index.php?itemid=26 Mon, 03 Jul 2006 15:55:24 -0400 <![CDATA[Driving a manikin with DMU Kinematics]]> http://2htts.com/CATBlog/index.php?itemid=25 In the kinematic assembly I made a mechanism where the reference part in the manikin assembly was the fix part and used the same part to make a revolute with the hub part.

And also I had to set in tools/options the manikin constrain resolution updates to automatic

Dowload the

]]> General http://2htts.com/CATBlog/index.php?itemid=25 Mon, 03 Jul 2006 09:04:03 -0400