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By Chris McAndrew, October 29, 2013
MCAD systems such as Solid Edge often employ a separate file type for sheet metal designs. The purpose of this is to open a host of functions that are relevant only for flat designs while presumably maintaining the stability and enhancing performance. Solid Edge stacks up well on all the basics and even offers some additional features for designing for sheet metal while integrating the features well into the overall software system.
Designing a flat part required that I take advantage of all that ST6 has to offer while still forgoing certain options at times. The feature to specifically forgo was portions of the synchronous technology and live rules. Even though the push-pull nature of the synchronous technology is nice, when getting into the details of corners, bends, and overlaps a hybrid of both ordered and synchronous systems was required.
Taking advantage of the whole system is another story and is one of the prime feature enhancements of ST6. Sometimes flat designs are obvious sheet metal components and occasionally related items such as packaging design from corrugated material. However, while many of the features relegated to sheet metal file types are specific to their design there are times where these design techniques can be used elsewhere. The Solid Edge team knows this as well and one of the nice benefits of ST6 is that it allows for sheet metal features to be added to any part, not just a component that was designed from scratch as a sheet metal component.
I tested a number of existing files, and only one failed to allow me to add the sheet metal body and features. Of course this opens up sheet metal features to similar items, like stamped components or deep draw parts that are not strictly "sheet metal."
The results of testing this first enhancement were indicative of more to come. Across the board, the sheet metal design components feel more integrated into the overall system than I remember from previous versions of Solid Edge and other systems, such as SolidWorks. When adding straightforward sheet metal features, like bends and dimples, Solid Edge ST6 makes things very easy. Other noted enhancements allow features to be created in a flattened mode and across bends; I found that these also worked smoothly.
There was one headache in working with the system. The steering wheel, used primarily for synchronous editing, is partially hamstrung by design constraints in sheet metal. I found using the steering wheel more clunky and cumbersome mostly because of the live rules associated with the face selected. This was solved however when I completely turned off live rules.
Figure 1: This many live rules linked to one face becomes cumbersome. Turning them off improves workflow
At first making edits to a simple L-Tray design was causing me fits but the problem was quickly rectified. Although there are design symmetries in sheet metal I continued to find that the software picked up many more relations than I intended. The Solid Edge team confirmed that they find most users feel it is easier to start with live rules turned off and then selectively turn on relations on a per flange basis. This worked well and managed to erase the frustrations I was having, though it was also useful to really know the live rules.
This learning curve for each live rule is something I remember from my first foray into Solid Edge with solid bodies too. Although each of the rules is highlighted with a related icon I remember it being much easier to recognize each relation. Granted, the first time around I had dedicated trainers to help me learn my way. For experienced users you can expect to breeze through this learning curve but new comers are wise to take some formal training as it will greatly reduce the time it takes to learn the nuances of the system.
Flattening the part is easy. Even though the Flatten command is hidden away on the Tools tab, I found using it results in no problems. Upon clicking the Flatten button, Solid Edge ST6 immediately forms the flat pattern, and then generates the major dimensions. Larger designs that had hundreds of bends and folds require some update time, but my basic L-tray box updated with no lag at all. It is important to note that unbending and flattening a part are not the same thing. This is actually a nice benefit. Features that have to extend across a bend become easier to create using synchronous since the software does not have to figure out the cumbersome order of when and how a part was unbent. It is possible to simply unbend a flange, add a bead or louver across the bend, then refold the part. The end result is an easy to add feature that is more accurate to real production.
Figure 2: Flatten button on the Tools tab (top); major dimensions created by the flattened design (right)
From here I worked with the design a bit more, adding notches and beads, alternating between flat and folded modes without any issue.
For users looking to maximize material utilization, you can expect some additional effort as there appears to be no functions to help generate layout patterns for multiple die cuts - but I must admit I have yet to see this capability in any sheet metal design package. Most often this is handled by a third party software. This may be something to think about if you are pricing new systems but when moving systems or upgrading it is sufficient to work in your current configuration.
Overall Solid Edge ST6 sheet metal offers a solid feature set that complements the main design software. For companies and designers who use sheet metal Solid Edge ST6 is sufficient and provides enough power to be both useful in the long run and relatively simple in the short run. If you are upgrading from previous versions and are already working with sheet metal, the enhancements are nice and the stability of the system while working with sheet metal files is great. Solid Edge ST6 performed admirably for me in the area of sheet metal components.
|Christopher McAndrew develops and markets toys and children's products. He has a bachelors degree in mechanical engineering from Tulane University. Chris writes the 3 Dimensional Engineer blog. More...|