How to handle Product designs, CAD models and Inprocess production drawings?

I'm working on a project where the client needs not only the end product design and model, they also need detail drawings for each step in the manufacturing process.

For example, one part is cut from structural shapes, then holes punched, the ends are profiled and finally rolled into an arc, before being welded into the sub assembly. Each step in the process the part is identified by a unique part number. The longest manufacturing process has nearly 20 steps along the way.

I am looking for suggestions and methods to accomplish this, and keep the entire model flexible without 100's of unconnected parts and sub assemblies.

My first thought was to start by modeling the raw material, and derive each part from the previous operation's part, but that doesn't seem very efficient.

The client is working with Inventor and is using Vault, however I don't think this discussion is software specific.

Any suggestions? Are there other software tools available to help keep things logically organized and straight forward?

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6 Answers

We have similar issues where I work, not as long but we do throw some assembly in at stages. If you have a unique number for each stage of the process you will want the drawing for the engineering of that process. Our staging is very simple, but we produce a drawing for each stage and document this, ie buy in extrusion A. machine A to become B. fit studs to B becomes C etc... (six stages max).

To do this in CAD (SW's) we model A, insert this into Model B (as parametric stock - feature in tree), add machining details.....six times.

Why do we do this nightmare..Because configs cannot be handled by our data management software.

I don't know PDM software that can handle configs effectively, we use DBWorks - low cost, this can't.

Gets very tiresome when you start to think about revision control in data management systems when using config's, rev control is at part level not config level.

We do use config's - but whenever there is a data problem, the best bet is always config related.

Split the stages up into individual models - we find it is safest way.

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That sounds like a reasonable method. I'll try this to see how it works.


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Kevin - based on experience, talk with your reseller about utilizing a PDM system to do this. I know Solidworks and Enterprise can, and as you said, it shouldn't be software specific or restricted. It would elimintae the configuration debacle many users experience.

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This is a broad topic which requires far more space than is available here. Remember this, if you're prototyping, your goal is steel (or whatever material) on the test bed. Don't try to show off your Cad skills. Get the concept together. Get what you need out to the vendors for fabrication (or in house fabrication, if you're so fortunate) and get that prototype built with no more effort than is necessary. This is a fast changing environment and all of your work is likely to change, frequently. You need to know finally, that the concept performs to specification. Analysis will give you a comfort zone; the prototype will demonstrate reality. Until you have a viable concept grounded in demonstrable results you have nothing. All Cad activity that doesn't lead to that end is wasted. When you have a field tested prototype that demonstrates you have met specification complete with all the additional requirements (UL, ASME, Department of the NAVY, Nuclear Regulatory Agency...) and you're ready to go into production all the additional Cad activities will become necessary and be defined by company standards. Much of this depends on what part of the design cycle you work in. As I said this is a broad topic with lots of caveats. There are many methodologies "Top Down", "Bottom Up", "Volume Assignments", often I don't use any until much later. It depends greatly on what you're asked to do and in what time interval are you to do it in. I use the kiss principle (keep it simple stupid) or as I call it slash and burn modeling. I make only what is necessary to communicate what I need done, right now. If that means a sub-assembly, good. But, I won't make a full up assembly unless the vendor is suppling me with a complete assembly and I need to control that assembly. Drawings are created only as needed to communicate intent to the vendor or fabrication personnel. Yes, they conform to a company numbering system and pre-release revision constraints (as do the models) in a vault or at least backed up from my computer daily but, keep it minimal. If you work in production or value engineering you will conform to the established company standards for those groups. In any case remember that someone, eventually, other than you, will ultimately have to interpret your models or drawings without your assistance.

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In sw exist a feature named "design journal" where you can create almost all sequences of your work and with cooperation with original drawings can explain all. Unfortunately I dont know that feature has automatic update- this create a word doc file which you can save separately. Second problem is that you must design your part as will be manufactured step by step but it requires a very good knowing of manufacturing proceses!

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