NX11 - Flat Pattern with solid bodies?

[Kenja824]

General Motors gives us body parts we need to work with. These parts, though sheet metal would seem to make sense, are made with solid bodies.

One of the jobs we need to do is create flat pattern type of views of these parts for weld templates.
1) The product which are solid bodies (we have no choice on that) needs to be flattened.
2) The centerline of the sealer bead and the points for the weld spots are shown.
3) The outer edges in the view need to be one color, the inner edges (holes and cutouts) another color and the centerline of bead and weld spot points another color, smooth edges another color, etc....

The process we use now....
Wave Geometry Linker -- Using Face and Face CHain and with Extract without Holes, and Use Display Properties of Parent checked. --- We select the surfaces we want for the templates we make and crate the Linked face feature.
Flattening & Forming -- Using Flattening, we select the surfaces, select an origin point and use the Transformation Objects to select the beads centerline and weld spots points.
Then we remove Parameters, which turns the surfaces into bodies (I think) and we delete the original linked geometry surfaces. (Note: We always set a new layer for each template we are creating so that when we are done, every one of the flat views in drafting will show different layers.

This hasnt been too bad. Where we really struggle now is changing the colors of the curves and spots and centerlines manually. The old flattening program used to have a settings button in it where we could assign colors and line fonts and it would make everything the right color automatically. This new Forming & Flattening does not seem to have this ability.

1) Keeping in mind we get the product directly from GM and it is already solid bodies, are we on the right path on how to go about this now, or is there a new way to do things that would make it much easier?

2) Looking on line, I found there are such things as Flat Pattern views in drafting, but I cant figure out how to do this. I am thinking because we are stuck using solid bodies and not sheet metal, this type of view is not available or something?

3) Right now I am thinking of trying to create journal code that will automatically color scheme the lines we select somehow. I am not very good with Code. In fact I suck at it. Is this still my best option or is there a way to do this in settings somewhere?

4) Any advice is appreciated. Whether I can end up using it or not. lol

 

[cowski]

I'm no sheet metal expert, but here's my take. When you switch to the sheet metal application, there is a command that will let you convert a solid body to a sheet metal model (assuming the solid follows the design guidelines for sheet metal parts). Once the body is converted, you can use other sheet metal commands such as flat pattern or flat solid. If the parts are not too complicated, this might be a fast way to get what you need.

www.nxjournaling.com

 

[Kenja824]

Unfortunately, we work on the complete car or truck at one point or another and many of the parts have a lot of bends and contours. Especially when you get in around headlamps and stuff. I will toss the option out there for them but I dont believe they will go for changing the body parts to sheet metal. Though you gave me an idea another problem we are dealing with. But that will be for another thread. lol

 

[Rob_N]

From my experience, GM and other OEMS a bastardized way of working with Sheet metal. Some things are done in sheet metal, others are done the "old way". meaning they start with a solid block and chop away at it to get their end result. Getting a flat pattern is a PITA. The forming and flattening module isnt very accurate. I tend to use a mix of Unfold and analyze formability -one-step commands.

 

[Toost]

There are basically two types of sheet metal shapes, the bent and the pressed/formed.
An straight L-shape can be an example of the first and the inside of a hood can be an example of the second.
The NX sheet metal flatpattern handles mainly the bent type. It has been extended to cover quite some pressed shapes as well but it does not handle the inside of the hood.
that shape is too complex to flip-flap back and fourth. You are down to the more advanced methods with cover large deformation / thinning / springback.
You say you get solid bodies, and why should you not ? Everything has a thickness !
Cars used to be modeled with surfaces only, but if you model with a solid / thickness, you gain quite some detail. All the junctions/ joints are there to be designed in full 3D instead of imaginary work. Bend radius's must be considered, in a single surface this is much more difficult.

Can you create some "similar" model which shows the difficulties you encounter, ( no copyright/ no secret data)
and upload that ?

Regards,
Tomas

 

[Kenja824]

Forgive my over detailed explanations and stressing they are solid bodies. In the past I have found that with Flattening, I get a lot of replies pushing me to use Sheet Metal Applications. I was trying to head that off instead of getting into it all again. Having pretty complicated product and all in solid bodies, we are sort of stuck (to my understanding) in doing our work in modeling. But if there is an easier way in sheet metal or just in drafting even than what we currently do, I am all ears.

I am attaching a power point someone made up on how to do this particular job. I tend to think this is the easiest way for us except for when it comes to extracting edges and manually changing the colors of the lines according to whether they are inner edges, outer edges, smooth edges, or hidden edges.

You will also find they are copying and pasting the extracted lines now too. I thought this strange but he said that after extracting the edges, when he clicked on "Save View" all of the extracted lines disappeared. This is a new problem we are experiencing with NX11 and I havent even had a chance to look into this yet. Im guessing they left them associative and moved the layer when they moved the faces to a different layer or something like that.

So, I guess I am looking for two things.
1) Looking at this powerpoint and the end results, is this the best way or are we going about it a hard way and dont know the easier way?
2) Is there any way of setting some preferences or something so that the lines will be the correct colors when we extract them? The old Flat Pattern we had in Modeling in NX9 had a setting attached to it that allowed them to set the colors. Apparently when Siemens got rid of this and went to Forming and Flattening, they didnt feel this was important to keep. P