Making a Twisted Sheet Metal Part 4

[CAD2015]

In some product applications we need to make a sheet metal part that has a twist in it. How can we create it?

How should a Twisted Sheet Metal Part be modeled in NX? What feature (other than Free Form Feature) should be used?

Thanks

 

[CAD2015]

I have an example to support my question......

 

[CAD2015]

I have another example to support my question......

 

[JohnRBaker]

What version of NX are you running?

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.

 

[CAD2015]

John,
I use NX6.........

 

[JonSelby]

In modelling I'd just use a 'Through Curves'.
I've not got enough experience with Sheet Metal to suggest a route there.

 

[mmauldin]

Here's one way. Not many features.

 

[SiW979]

Hmmm Law curves

I managed to replicate your model mmauldin, however law curves are vague and somewhat mysterious. I remember doing something with a sweep where the area was defined by a law curve to remain the same through difference shaped sections like a molded rubber hose on a car for instance, and for some strange reason, the area the area defined by the position of the start point of an associative curve relative to the ABS in the Y direction. What on earth is that all about?

Has anybody got anymore good examples of models that use law curves that I can pick through please?

Many thanks.

Best regards

Simon NX4.0.4.2 MP10 - TCEng 9.1.3.6.c - (NX7.5 native)

http://www.jcb.com

Life shouldn't be measured by the number of breaths you take, but by the number of times when it's taken away...

 

[John2025]

mmauldin,
Very nice, but how the heck did you figure that out? I assume that angular law is using the delta y value as the degrees of rotation, but I can't find anything in the documentation that describes it. I'm with JCBCad, any more examples, and/or documentation?
Thanks
John

 

[FrankSwinks]

I understand you asked for a method that did not use freeform features. The attached part does use ruled surfaces. This part is fully parametric. The end blocks may be rotated and/or translated as you wish. The important associate features are the four studio splines which must be created as degree 4 and are created through the block corner points and tangent (G1) to the edges of the blocks.

If this meets your requirements it is possible to write a journal to automate the creation of the twisted piece.

Frank Swinkels

 

[eex23]

Here nx7 file. there is also animation of actual twisting (view->visualisation->create animation....)
the model is fully associative.

 

[RobLN]

Very impressive mmauldin, it's not obvious how you turn a stright line of length 90mm into a twist of 90 deg. It would be nice if you could elaborate on the law curve method step by step as it seems to be a very efficient way of producing geometry. I note that you used the same method on a coil spring also where the 2d line drives the behaviour of the spring. However I can only describe what it does rather than explain it


Solid Edge; I-Deas 7 to 12; NX4, NX5 & currently NX6.

 

[SiW979]

Have a look at the attached model. How would I create the twist in the middle so it stays nice and tangential using a law curve.

I'm feeling a few shiney purple stars being dished out!!



Best regards

Simon NX4.0.4.2 MP10 - TCEng 9.1.3.6.c - (NX7.5 native)

http://www.jcb.com

Life shouldn't be measured by the number of breaths you take, but by the number of times when it's taken away...

 

[cowski]

Here's another way. It does use a freeform feature (through curves) but is fully associative and does not use law curves. I originally posted it in another thread about a year or so ago.

 

[mmauldin]

Another version.
No law curves.
Smoother than law curve version.
Maintains thickness and width.

 

[mmauldin]

Simon,

I'd like to put my 2 cents worth in on your law curves part but I am stuck back here on NX6.

 

[cowski]

I'd like to put my 2 cents worth in on your law curves part but I am stuck back here on NX6.

Same here.

 

[CAD2015]

Thanks to all that sent answer to my request!
For mauldin, FrankSwinks and eex23:
Could you gentelmen, please, resend your links for NX5 or NX6? I do not have access at NX7 or NX7.5!
Thanks!

cowski: Thanks a lot for your attachment; It has been sent for NX5 or 6 and worked perfectly!

JCBCad (Mechanical):Thanks for your comment.

 

[FrankSwinks]

Attached is an update. It is NX6. On layer 1 are the two end pieces. Layer 2 has the twisted piece using through curves with G2 continuity. Layer 3 has the twisted piece using through curves with G1 continuity. Layer 4 has the twisted piece using studio splines and sewn ruled surfaces.

I think the through curves is simpler then the layer 4 option however if you wish to modify the shape to have it closer to reality (if that is important) then this can be done by moving the three internal spline poles for each of the four splines. You can certainly see the difference between the G1 and G2 examples.

Frank Swinkels

 

[cowski]

I originally posted it in another thread about a year or so ago.

OK, so it was more like 2 1/2 years ago: thread561-229687