Considering quite a few sheet metal shops are experiencing a bit of a downturn at the moment it maybe worthwhile looking at faster, more efficient methods of sheet metal development and design. I still remember spending many hours on a drawing board at college trying to work out a square to round transition and truncations. This was a lengthy process on a drawing board and not much quicker on AutoCAD due to having to work out the development and plan and the bending orders. Some of you may have heard of Autodesk Inventor or even used it. The 2010 version has had numerous improvements and one such improvement is to the sheet metal environment. You can now generate lofted flanges which make sheet metal design a snip.

Let’s take a few minutes to look at the workflow and benefits of using inventor.

We basically start in a sketch and define the profiles that we are to loft through.

It is then time to use the new feature, Lofted Flange. This new tool allows the flange to be developed using two manufactured processes. The flange can either be formed in a brake press with folds or die formed. For this example I am using the brake press method. You can also control the distance between facets, the angle or have inventor automatically control the number of facets based on a tolerance you input.

Next we select both the open profiles and Inventor will do the rest of the hard work.

You can then add additional flanges and holes as required. It’s worth bearing in mind that the whole model is completely parametric and based on sheet metal bend rules which are style based.

Once you have you model fully developed you are then ready to produce a flat pattern and some manufacturing drawings. The flat pattern is literally one mouse click away. Inventor will work out the folding sequence and also calculate the length and width of sheet metal required for the development. If there are any clashes whilst unfolding the model, Inventor will produce a suitable warning!

Finally, below you can see a drawing showing the flat pattern development and a 3D view. This can then be exported to a DXF file for manufacture.