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Sheet Metal for Paper?!

NX7.5 Sheet Metal took a little getting used to after using straight beak sheet metal for years. However, I was sold very quickly when I began using the tabs, flanges and especially things like the bend and the contour flange command. The first thing I was delighted by was the preview capability and the fact that I could pull the entities back and forth in real time. As I learned more of the commands I found out that NX Sheet metal has a lot more functionality as well as reliability and usability. They say that sometimes the best teacher is a production job and a deadline. It just so happened that the creation of our latest product required packaging. The product is an in wall charging unit that is capable of charging, at full rate, your iPad, Droid phone, game controller, camera or many other devices. It took a long time to complete the electrical engineering, the product design, the testing. Finally we got to the point of needing a good package for the product.  After we got several quotes from various package manufacturing firms, we were stunned by the high price and the slow turn around. We were really in a hurry though so we decided to design the packaging ourselves. Along the way, we had to familiarize ourselves with some of the requirements of what we then called card board but were later corrected to say “chip board”. We knew that we wanted a package that would show the product, that would display the bar code, that would hang at stores like Fry’s electronics and so forth. Our desire was to create an elegant package without going broke in the process. The choice of colors and the graphics were done semi-simultaneously with the chip board design.

We began by taking the assembly of the product and creating a parasolid of the entire thing including the manual and the little bag of wire nuts etc. Then we created what we thought would be an appealing shape around the parasolid model.

Fig 1 The assembly model of the entire product including wire nuts and manual

Fig 2 The exploded view of all components to be packaged

Fig 3 Solid shape created around the solid

Once the solid shape was created the convert command did an awesome job of creating the detail wall thicknesses and bends.  The thickness of the chip board we chose was .03 inches. We applied a shell to the model using the “shell all faces” option. It was important to first set the preferences so the sheet metal acts like paper. The bend radius was set to .015 and the other values were set.

Fig 4 Set up the preferences for chip board

As the convert command was used the edges were selected to signify where the cuts were to be.

Fig 5 The bends and the cuts are made in the conversion

When the edges are selected well, the convert option does a nice job. The flat pattern should be checked before going to the next step.

Fig 6 The flat pattern checks out OK and the flange is offset by .02

Once the flat pattern checked out, we were able to begin to add on all the flanges that overlap. The flap that is overlapped must be offset by .02 in order to stop it from interfering.

Fig 7 The window is cut out and the hang tabs are added using hem

More flanges were added as things progressed. The window was added using Insert / Cut / Normal Cutout. The hang tab is a piece of chip board that is folded over and pressed. It could not be created using the Flange command because the flange command would not accept a bend that is 180 degrees and a bend radius of zero. The hem command was perfect. The tab also contained a cut out that was made using the Normal cut out command.

Fig 8 Cut out performed after the unbend

Fig 9 The preliminary drawing that went out for manufacturing

Fig 10 The actual Packaging

Once the flanges were all done, the PSA (pressure sensitive adhesive) was added to the flanges.

The folded box fit the product well. It had lots of room for the product and the manual. It was relatively inexpensive.  Once we were done with our design, it fit the product, and we had thousands packages ready to go. We sold quite a few units when we got new information.  We were told by our biggest vendor that only the “blister pack” would do. We were also told by another vendor that we would need to package four of the units at the same time.  Consequently another round of packaging design was done. The old packaging was discarded. It broke my heart to see hundreds of copies of the initial packaging go straight to the land fill.

Fig 12 The CAD model of the blister pack

The CAD modeling shown above was done using extruded sketches then applying the shell command and all the sides and back of the model. It worked like a charm.

Fig 13 The new blister packaging

One of the vendors required us to design and build the displays that will be mounted on the shelf above the pegs upon which the product will be sold. Of course NX8 made this easy. In an effort to figure out how the entire project would look we used the “decal” command as shown below. The manufacturing technique was simple. Solvent bonded sheets of Plexiglas.

Fig 14 The CAD model of the display unit

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