Reversing the direction of a POINT SET is created in NX6

[rtbdcl]

I'm currently creating surfaces on a model that has been created from GOM'd point cloud data. So far I have created datum planes at set distances to cut through the GOM model body, this then allows me to create a closed spline matched to the profile of the 'cut' surface. My next step is to create point sets, that will then allow me to create splines & eventually through curves that will allow me to create 6 surface profiles that will make up the blade profile.

So far, I have managed around 80% of the required point sets, but for some reason, the remaining point sets are being created on the reverse side of the aerofoil profile. I was thinking that there would be a simple fix like 'Reverse Direction' but after hours of trying various alternative methods, can't seem to find a solution. If anybody can decipher what I'm trying to ask, any help would be GREATLY appreciated.

Many thanks in advance.

 

[JohnRBaker]

You'll have to supply, if not the actual part file, at least a picture of what you're doing and something which shows what you call "the reverse side of the aerofoil profile".

John R. Baker, P.E.
Product 'Evangelist'
Product Design Solutions
Siemens PLM Software Inc.
Industry Sector
Cypress, CA

http://www.siemens.com/plm

http://www.plmworld.org/museum/

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

 

[rtbdcl]

Thanks John. I hope the attached file makes my query a little clearer. (If the file hasn't uploaded properly, apologies. it's the first post Ive done that has needed an attachment).

Cheers.

 

[JohnRBaker]

The pictures help, but without the models it will be very difficult to comment on why you're seeing the behavior which you are.

John R. Baker, P.E.
Product 'Evangelist'
Product Design Solutions
Siemens PLM Software Inc.
Industry Sector
Cypress, CA

http://www.siemens.com/plm

http://www.plmworld.org/museum/

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

 

[cowski]

Can you use the 'edge' splines to divide your cross section spline and then just add the point set to the required side?

 

[rtbdcl]

Cowski,

I've tried using trim curve to do this, but it gives the same result in that it trims the 'reverse' side. I'm sure that there are work rounds for this operation, the fact that all the other splines have 'functioned' properly & I've got the result that I require has made it more of a task to find out why the remaining few won't.

John,

I've atached a model with some of the initial GOM'd data removed that you will hopefully be able to follow my process. A similar task has already been completed & I'm following the process set out in that model, so as mentioned previous, it's probably more for my own knowledge & future reference now.

If you follow the point sets in SURFACE_POINTS2_LAYER17, you'll see that all but the last point set has been applied to the required surface but Point Set (419) is on the reverse side. Again, any advice would be appreciated....this is driving me insane now!!

Cheers,

RTBDCL

 

[cowski]

Attached is a copy of your file that I modified. I copied the trouble splines to layer 256 and colored them purple to distinguish them from the others. I used divide curve - by existing objects and used your guide curves to divide the section. There is a sharp corner in the section you are interested in, which may be the cause of your problems. I used join curves to get 1 continuous segment and then I applied the point set.

I notice that your section curves are degree 1 splines and your guide curves are degree 2 splines. If you have the option to use degree 3 splines (or higher) for both, you may get better results.

 

[JohnRBaker]

It appears that cowski has discovered and resolved your issue. And his comment about degree 1 and 2 splines is correct, and while they are fully supported, like most other CAD systems over the years, NX has been optimized to support degrees 3 and/or 5 splines (you will note tha most functions which produces a b-curve as a result will generally default to a degree 3 spline, unless explicitly overridden by the user).

John R. Baker, P.E.
Product 'Evangelist'
Product Design Solutions
Siemens PLM Software Inc.
Industry Sector
Cypress, CA

http://www.siemens.com/plm

http://www.plmworld.org/museum/

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

 

[rtbdcl]

John/Cowski.

Thank you very much for your help. I'll give the tips a whirl. If you don't hear from me again on this one, take it that you've resolved my issue.....or it's all become too much

Thanks again,

RTBDCL