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Flatness 1

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If the faces-of-interest are supposed to lie on the XY plane of the WCS and that's what you're attempting to verify, try going to...

Preferences -> Grid and Work Plane...

...and in the last section of the dialog, toggled ON the 'Dim Objects' option and hit OK. Now if those faces actually are ON the XY plance of the WCS they will appear as normal, but it they are not they will be translucent. You could also toggle ON the other option that section of the dialog, 'Make Non-selectable' and then you could test it by attempting to select the Faces or not since only those actually lying on the XY plane of the WCS would be selectable while all other faces would not be.

John R. Baker, P.E.
Product 'Evangelist'
Product Engineering Software
Siemens PLM Software Inc.
Digital Factory
Cypress, CA
Siemens PLM:
UG/NX Museum:

To an Engineer, the glass is twice as big as it needs to be.
 
Hi John,

Thank you for your reply. In my preferences there is only grid but no sign of work plane?? and there is no dim objects option. I have attached a jpeg of my preferences options I don't know if I am looking in the wrong place or my preference options are different to yours I am using nx9.

Thank you.

Regards Daniel Lamb.
 
 http://files.engineering.com/getfile.aspx?folder=136af9d6-3a3b-40b2-bea9-2c23a01ebc04&file=grid.jpg
Daniel,

Search for "Work Plane Emphasis" with command finder. (MP3 - "Show On View Tab")
Or "View" (tab), Visibility (Group), More, (visibility), More Gallery, Work Plane Gallery, Work Plane Emphasis"

HTH, Joe
 
What version of NX are you running?

John R. Baker, P.E.
Product 'Evangelist'
Product Engineering Software
Siemens PLM Software Inc.
Digital Factory
Cypress, CA
Siemens PLM:
UG/NX Museum:

To an Engineer, the glass is twice as big as it needs to be.
 
The method described by John and Joe is a bit more graphical than this,
But, another way of checking is Info- Object ( Since this invaluable command no longer has a menu position that adult males can remember... I press "Ctrl+I" ) then select the face + OK

In an analytic world, the face type is Planar, the point ZC= 0 and the Normal as seen below.

Surface Type Planar

Point XC = -2550.000000000 X = 1300.000000000
YC = 940.000000000 Y = 1540.000000000
ZC = 0.000000000 Z = 2315.000000000

Normal - Absolute I = 0.000000000
J = 0.000000000
K = 1.000000000

Normal - WCS I = 0.000000000
J = 0.000000000
K = 1.000000000




Regards,
Tomas
 
Hi Tomas my info window does not contain the yc or the zc can I change what the info window show me?

This is what I get

Information listing created by : PMILL
Date : 31/03/2015 17:47:06
Current work part : R:\NXmodels\Job_No_3548_Rototek_Target housing tooling part no 22-1992-2\Job_No_3548_Rototek_final
design_Target housing tooling part no 22-1992-2.prt
Node name : d1453
============================================================
Information on object # 1

Owning part R:\NXmodels\Job_No_3548_Rototek_Target housing tooling part no 22-1992-2\Job_No_3548_Rototek_final design_Targe
t housing tooling part no 22-1992-2.prt
Layer 80
Type Face
Color 14 (Pale Emerald)
Font SOLID
Width Thin
Modified Version 89 17 Mar 2015 15:51 (by user PMILL)
Created Version 89 17 Mar 2015 15:51 (by user PMILL)
Information Units mm
Surface Type Trimmed B-SURFACE
Normal - Absolute I = -0.382633392
J = 0.000024780
K = 0.923900258

Normal - WCS I = 0.000032787
J = -0.000000138
K = 0.999999999

------------------------------------------------------------
Face Attributes:
Grid Count - U 0
Grid Count - V 0
Translucency 0%
Partially Shaded No
Face Analysis No
Degree in u 3
Degree in v 3
Rational status Polynomial
Number poles in u 4
Number poles in v 4
Number C0 seams u 0
Number C1 seams u 0
Number C2 seams u 0
Number C0 seams v 0
Number C1 seams v 0
Number C2 seams v 0
Number patches in u 1
Number patches in v 1
------------------------------------------------------------
Object Dependency Graph:
Face - ID 487816
|________ Extracted Body(3233)
Used by:
Datum Plane(3243)
 
[pre]Modified Version 89 17 Mar 2015 15:51 (by user PMILL)
Created Version 89 17 Mar 2015 15:51 (by user PMILL)
Information Units mm
Surface Type [highlight #FCE94F]Trimmed B-SURFACE[/highlight]
Normal - Absolute I = -0.382633392
J = 0.000024780
K = 0.923900258[/pre]

It appears that the face is not of type 'planar'. Is this a native NX file (with modeling history) or are the bodies a result of importing geometry from a file (STP, IGES, etc)? If the geometry is imported (no modeling history), you could try the "optimize face" command to clean up "nearly planar" surfaces into truly planar surfaces.

www.nxjournaling.com
 
You have selected a face which is of type B-surface ( = Nurbs = can be any shape including flat)

Since it "might" not be flat ( your face has the "ability" to be s-shaped in both directions since it's degree 3 x 3 and 1 x 1 patches)
the normal is "tricky" because it's depending on the position , -where on the face we check.
NX will present "normal values" but the point is per default at 50% x50% . See the attached image .
( there is somewhere an option to report the normal at a position on a face but i can't remember where / how at the moment)
If this face is flat despite the degree 3 etc, the normal might not be possible to calculate exactly due to the math involved.

Regards,
Tomas
 
 http://files.engineering.com/getfile.aspx?folder=4ca4308f-cebb-42f0-ad4d-870f8a793145&file=normal.png
You could also use the 'Face Shape' Analysis tools to verify the characteristics of a face of a model.

For example, in the attached video, I've created a simple part and the top face, while it looks planar is actually a B-Surface with a slight 'pimple' that you can't really see just by looking at the shaded image. What I've done in the video is create a two-view layout showing the same view of the same model and then in one of the views I applied a 'Face Shape' test using a 'fringe plot' to highlight any sort of 'Radius' area on the face. As you can plainly see there is indeed a slight non-planar region of what otherwise looks like a planar face.

John R. Baker, P.E.
Product 'Evangelist'
Product Engineering Software
Siemens PLM Software Inc.
Digital Factory
Cypress, CA
Siemens PLM:
UG/NX Museum:

To an Engineer, the glass is twice as big as it needs to be.
 
 http://files.engineering.com/getfile.aspx?folder=08113022-687e-4077-8ce3-b57a5a7d73a9&file=Flatness_Test-JRB-1.mp4
thank you for your help.

Regards Daniel Lamb
 
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