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Watch Advanced 3D Solutions For Manufacturing Engineers
This MMT inMotion presentation from Parametric Technology Corporation (PTC) demonstrates the latest techniques and technology in production and multi-axis milling, moldmaking, and sheet metal programming.

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Mold & Tool Design/Production - Transcript
(Select the link below to access the entire presentation.)

Another key attribute for an advanced manufacturing system is going to be specialized tools for tool design. You will want tools, depending on your processes, for injection mold, for castings and forgings, and for progressive die design. You don't want to have to go out to a separate system to be able to complete all of the manufacturing engineering tasks required to get these jobs out the door.

One of the most common tasks in tool design is the core and cavity creation. It needs to be associative to the design model, meaning that if that design part changes, you want your tool design to change. On the other hand, if you have made part modifications within your tool model, you want those to stay - keep your rounds and your drafts. But if the customer changes a diameter or a draft, or adds a feature or deletes a feature, you want your core and cavity to update. You need to be able to put in those features, such as shrinkage, and then you need to be able to build the tool geometry, build parting lines and parting surfaces, sliders and lifters, all of those various pieces that make up the mold. You want specialized, easy to use tools to quickly build these, maybe even automatically build them, and give you the flexibility to build exactly the tool geometry you need.

For those of you in the injection mold world, you want to choose from a library of vendor moldbases to be able to complete your moldbase design. You might want to take an existing moldbase and customize it to your needs, store it in your library, or even build your own custom moldbases from scratch and store in your library. Either way you can reuse them, quickly and repeatedly. You probably want to do a cavity layout in 2-D, looking at various arrangements for quick what-ifs. But then you want 3-D models to fall out from that 2-D arrangement, with solid models of all tools, plates, and equipment, along with a complete bill-of-material and drawings for all components. Then you can finalize the designs with cooling designs and ejector pins, all of the information necessary to generate models and drawings you can send to the shop floor or send to your vendors.

Finally, if you are truly working art-to-part, you will take that core, that cavity, your tooling plates, and take them down to the shop floor and machine them, and you will want your manufacturing system to be able to accommodate that. You want it to be fast, very automated, but you want it to apply your machining strategies, not some default methods. You want to have defaults to use one tool for roughing, a second tool for reroughing, a third for a semi-finish pass, and so forth. You want to store that strategy and simply apply it for each new part. You might use high-speed milling wherever possible, and as always, you want it to be associative, all the way back to the design part. If the design part changes, your core and cavity changes, your moldbase changes, and your toolpaths to cut out the tooling changes. That's where you really start making money with an advanced manufacturing system.

Let's look at that from an injection mold standpoint, taking a part all the way, from art to part. In this case we will go back to our top level assembly, and look at the headlights that we have on the top of the cage. Here we have a fairly simple assembly, and the back piece is a plastic housing that is both the reflector and the bulb holder. That's the piece we want to work with today.

I have my design model complete, or more likely nearly complete, and we will go in to my manufacturing model. Here is where I will bring in a copy of my design model, because what I want is that if that model ever changes, I want my manufacturing model to change immediately, I will look at maybe a rectangular pattern of cavities, or maybe a circular pattern, and I will go ahead and put in the shrinkage. Maybe I want 2% shrinkage, whatever is appropriate for the material. I will put that part inside of a workpiece, as this is what I will build the core and cavity out of. The system automatically looks at the model and suggests a minimum size, and I will add and extra inch or two as needed, whatever I need to build my tooling plates.

Once I have that, since the system already knows the pull direction, I can have it look at the model and generate a silhouette curve. For a part that is well drafted, I can simply pick on that curve and extend it out, and there is a parting surface, or at least the start of one. That is the sort of quickness and flexibility that you really want. You might go in and make it more complex with a shut-off plane and a shut-off boundary, but you want to be able to quickly build that parting line and build that parting surface. Once I have that surface, I can select it and have the system split the workpiece, extracting out the geometry of the part, split it at that parting surface, and generate 3-D solid models of the core and the cavity along with any sliders.

I'll take that solid model, in this case the core, and put it inside of a workpiece. Staying in the same environment, now let's build a milling operation. I apply my standard strategy, in this case starting with a certain end mill, a certain step depth and stepover, all the ways I like to machine these parts. In this case I brought in the roughing tool that we see here, and then I will bring in a bull nose cutter for a rerough to clean up what the first tool left behind. Maybe I'll bring in a ball end mill after that for a semi-finish cut. Again, I define this strategy once, and then just apply that strategy for each new job. I might have different strategies depending on the job and the materials used, but I define them once and then reuse them over and over. That is the sort of productivity that I really want to have.

So I have my core and cavity milled out. Next I might want to put them inside of a moldbase. I will start in a 2-D layout environment where I can quickly see how many I can use with the various size plates. I want to choose from a library of various vendors, maybe a DME or a Hasco or a Futaba. I'll bring those library components in, work with them in 2-D for my layout, but then I want the system to automatically generate a 3-D model of this entire tooling assembly. I can always go back to the 2-D layout, maybe change the size of the plates or any other components, but when I am done I have a complete 3-D model. For any given piece, I can open it up individually and see the cutouts based on the appropriate tolerances. For each plate, I want to have a drawing to send to the shop floor, maybe with a top view and a couple of cross-section views, whatever I have defined in my standard drawing package.

So, we have defined our moldbase, I have machined out a core and a cavity, and of course this is when the customer calls and says, "The first part in the field failed, we need a stiffener bead!" I can make that change since I have a complete CAD/CAM system, or maybe I bring that updated model in from the customer. Either way, I have an updated model with whatever changes need to occur. So what happens to all of that geometry that we created downstream?

With a truly advanced manufacturing system, what that means is that my part is updated. If I look at my mold model, it already shows that my core and cavity have been updated, in this case with the geometry to create the new stiffening rib, exactly what I want. Here is my new core model and I can replay the toolpath, and it automatically accommodates all of the design changes. If we zoom in, maybe on the semi-finish operation, we can see how it is diving in there. So my roughing has been updated, and in this case I'll probably add one more mill sequence to mill that out with a small cutter. It is still up to me to say that the tool is appropriate, but for all of the changes, I just let the system do the update.

Back to the moldbase, it's the same situation. If I blank out the fixed half and zoom in, you can see that any changes are automatically reflected downstream. That is what you want in an advanced manufacturing system for tool design.