Modeling / Documenting Weldments

[VinceCiotti]

My question is about documenting things like weldments, castings and forgings. Items that start with an initial "rough" or "as produced" size/shape but require machining to reach their finished state. For simplicity I'll focus my question on weldments. In addition, I will be using PMI to document the product and Teamcenter to manage the bill of materials. Lifecycle Visualization (Vismock) will be used by downstream customers to view the product.

What I begin with is an assembly which is made up of a number of individual components. Each of these components are modeled in their "stock" sizes with no machined features (holes, tapped holes, chamfers, etc). This is the point I wish to document the weldment (weld symbols, welding notes, etc). Unless I'm missing something, the process up to this point is pretty straight forward.

Here is where it gets fuzzy for me. Now I want to "machine" the weldment. Before I go any further I do know about the Assembly Cut command. This command is not a good solution to this problem. Not being able to use the hole command is a deal-breaker. Whatever the solution is I need to have the following five items:

1) For ordering purposes the bill of materials should reflect the "stock" sizes of the individual components.

2) Access to the full suite of modeling commands as many of my weldments are very large and complex and can have 30+ machined features.

3) I must be able to document, using PMI, the final "machined" part.

4) Only the weight of the "machined" part should considered during weight analysis.

5) Each document (weldment, final machined) should be viewable by downstream customers in Vismock.

I have some ideas that involve layers, model views, body promotion and/or Wave linking and Reference Sets but I wanted to see if anyone else has come up with a good solution before I go and trial-and-error something. Thanks in advance as I realize this probably isn't a 30 second response. I look forward to hearing from the community.




Vince Ciotti
Mechanical Designer
NX9, Teamcenter 10
Windows 7 Enterprise
Newport News, VA

 

[PrintScaffold]

You may get some idea about questions of machining after assembly and aseembly weight calculation if you follow the link in my signature.

On the whole, this definitely isn't a 30 second response. Instead it looks more like a full-scale paid implementation project, which requires thorough analysis.

http://www.cadroad.com

 

[VinceCiotti]

Thanks for the link. While it didn't answer my question, I found the information useful and interesting. I have seen component groups before but didn't really know what to use them for. Out of curiosity, what did you mean by "paid implementation"? Are you suggesting NX can't do what I want out of the box?

Vince Ciotti
Mechanical Designer
NX9, Teamcenter 10
Windows 7 Enterprise
Newport News, VA

 

[PrintScaffold]

Mind that component groups have different purposes, what I shown is one of them.

As for the "paid implementation", I'm expressing opinion that your question is rather complex and involves different factors. At the end of the day, to answer it and many additional questions that it will generate is a lot of work.

http://www.cadroad.com

 

[PrintScaffold]

Don't get me wrong, I personally would even be quite interested to help you with this task.

http://www.cadroad.com

 

[HercalloY]

Vince,

This is basically a question i was wanting to ask as well. "how do people go about creating weldments/frames/structures within NX." I posed the question in simple terms a while ago (and got a stern "no" from Mr Baker) as i was trying to convince management of an upgrade and was trying to see if the newer versions of NX had some kind of support by now.

Now that i've finally got the go ahead for an upgrade and chose NX. i'm concerned i may have made the wrong decision in upgrading our NX and perhaps i should have gone with SW. hhmmm

I would really like to know how people handle these kinds of models in NX. I don't think Vince's question is to difficult to respond to, even if only an overview of what one may do.

 

[VinceCiotti]

HercalloY,
I couldn't agree more. I feel like this is basic functionality that should be built into the software. Maybe it is. Maybe its just not as intuitive as we would like. I hope this is the case. I've used a number of CAD systems over the years and from a modeling stand-point NX bests them all. Hopefully I can find a way to make this weldment process work.

Vince Ciotti
Mechanical Designer
NX9, Teamcenter 10
Windows 7 Enterprise
Newport News, VA

 

[cowski]

I've occasionally had to model/document parts in the as cast/as machined states. For illustration, let's say the cast part is 1357 and the machined part is 2468. We'd add 1357 (cast part) as a component to 2468 (machined part) and use the "promote body" function. This allows you to use all the modeling functions to add your machined features while keeping associativity to the cast part. The part structure also nicely worked with the BOM; you need to order/make P/N 1357 to make P/N 2468, which was obvious from the assembly structure. You could achieve the same result with wave linking the cast part body into the machined part file. If memory serves, promote body handled the part weight in a more "automatic" fashion. With wave linking, you are left with the component body as well as the linked body, you have to take care to remove the cast body from the weight calculations.

For parts that are welded together, you could use wave links or promotes to unite all the pieces together and add other features as necessary. If you want to use the "parts list" functionality, you may run into some issues (whether you use wave links or promotes) since the auto balloons attach to components and you won't really have component objects to link them to. However, I rarely did a welded structure with a parts list, so I'm getting out of my depth. Perhaps others can share their best practices for such situations.

www.nxjournaling.com

 

[dtharrett]

I am thinking reference sets would work well in this situation (each part has an "as cut" and a "post welded" reference set). As for the "stock" size showing up on the parts list, I would look at adding an attribute called "stock size" to each part and show that in a column on your assembly parts list (I am assuming you drop a parts list onto your assembly drawing).

 

[dtharrett]

Or potentially with arrangements, instead of reference sets (each member gets documented 2X, once with post machining...once as cut).