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Overall, stamped parts can be very challenging to “quickly” unfold with proper material compensation for an accurate blank layout. The difficulty is not the “initial rough” blank since crash-forming FEA software has been on the market for decades. The dilemma is staging (doing it in steps) the formation of the part since most parts are done in some sort of progression. Either a progressive die, transfer die, or stage tools are created to accomplish this process or series of operations.
Laying out this process in 2D systems is the common approach with simple notes and basic 2D cutting operations. The rest is left for the designer to “hopefully” compensate for during the design process with his or her mind’s-eye! This leaves the door open for many costly errors and days, weeks or months of frustration. Nonetheless, this has been the way it has always been done and therefore many are complacent with the 2D limitations. However, since 3D has become mainstream in the product development world tool and die makers are facing a new challenge—leveraging the 3D model throughout their design process!
The 3D evolution is happening right before our eyes. The majority of work tool designers are quoting comes in as 3D data in some form. In 2005, over 60% of tool designers were receiving 3D data to quote and design the tools. This factor grew from 45% to 60% the prior year so; this is no flash in the pan. Majority of 3D data should be a good thing however; most tool designers are only converting the data from 3D to 2D, and then doing the rest of the design in 2D. Then the CAM programmers work from the 2D drawings to recreate the 3D to program the CNC equipment. This is a major productivity lost to say the least!
2D design has no future—Major innovations are strictly coming from the 3D R&D centers throughout the world. For those who stay with 2D, as their main design tool will also have a limited future since, these individuals must take on the learning curve of this new technology. Since learning a tool proficiently doesn’t happen overnight they will have to learn at the worst time; when they have to! Also, product designs are much more complex and delivery dates shorter then ever adding even more pressure to the learning curve. If you are making blocks and cylinders type parts, 3D won’t be much of a challenge, however we know the majority are making parts with complex formed sculptured surfaces out of unpredictable new materials with incredible tolerances. Don’t wait until too long to start learning 3D—it is just the beginning of the road!
The design and manufacturing process of any sheet metal component must take into consideration unfolding the part—blank prediction. For parts that are designed native to the CAD system with only straight bends, this can be achieved by most CAD systems today very easily. However, reality sets in as soon as you import a part with deformed features (stretched or drawn material), complex bending and cutting. Besides being more complex, there are typically design errors, material variation, and flanging that can also cause many headaches even if unfolding in the native CAD system.
For these and many other scenarios, 3D QuickTools designed their own unfolding and strip layout engine to quickly delivery an accurate blank and process layout in record time all within SolidWorks; 3DQuickStrip and 3DQuickForm.
To start the process the system doesn’t require the part to be native to SolidWorks therefore, you can import the part via IGES, STEP, SAT, X_T, etc. The part can be either surfaces or solid. The part could have been designed with any method and technique—not requiring it to be a “sheet metal” type part. The part can also have any type of features including simple and complex multi-stage formed areas.
After the part is imported, 3D QuickTools examines the part and does automatic feature-recognition. The user only needs to establish the unfolding plane and bend compensation. The unfolding plane can be a flat face, an edge, or a reference plane entirely off the part. Very quickly the system returns with the automatic recognition results and the “Unfold Manager”. The Unfold Manager lists all the features and allows the user to adjust any parameter. For instance, if it is a round extrude, you can Zoom to, Unfold/Fold, and adjust the initial piercing diameter. This also is allowed for bends and embossments, lances, dimples, and compound forms just to name a few. If there are features that the system doesn’t automatically recognize, they user can assist the system using User-Assisted Recognition (UAR mode).
UAR mode allows the user flexibility to not only recognize complex areas but, also select what geometry on the 3D model should be used and not used. This mode will allow for material variations such as chamfering and cold forging. There are also many other feature types to support gussets, complex round extrudes, and complex bending conditions—including designer errors! The most powerful and flexible feature is called a User Defined Feature (UDF). This feature can assist in designing multi-stage forming operations that incorporate the initial blank, final form, and all other stages in between. These are called “states”. Each state can also have “steps”. States and steps are unlimited to support any stages a tool must perform.
To define the states of a User Define Feature users have three options. Manually create the internal state by using traditional modeling techniques, use the free-form geometric unfolder command built into 3DQF or use 3DQuickForm. 3DQuickForm is optional software that can be used with or without 3DQuickStrip. In general, 3DQuickForm works within the SolidWorks environment and calculates complex formed regions for blank development. It will take into consideration holding constraints, multiple projects, lubricants, material types and properties such as hardness. Thinning and thickening plot can also be displayed for formability concerns. We will cover the use and benefits of 3DQForm and 3DQForm Advanced in future articles.
The Strip layout is next in the series of events. This is where the modeling is done for the user and the process of “How with the tool work” comes into play. We will cover this in depth next month to conclude the 3DQuickStrip features and benefits!
To learn more and what else is new, you have many options to get educated about the ever-evolving products from 3DQT. Please contact your local SolidWorks reseller or Strategic Technology Solutions directly at 1-888-207-1096 or info@callsts.com. If you have some example parts you would like us to review, please email them to demo@callsts.com. Finally, if you are attending SAE show (Detroit; Mansfield Mfg.-Magnecomp Booth) or MetalForming 2006 (Nashville; booth 424), be certain to stop by our booth to see what's new with the most revolutionary release ever--Version 3! www.3dquickpress.com
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