Sheet metal design is one of the basic skills of a mechanical design engineer. I am a big fan of SolidWorks 3D CAD solid modelling software; it has a great suite of design tools specially for sheet metal design. Here is a quick look at converting a solid part into a sheet metal part. This is not a masterclass in design, just a small, simple example of how good SolidWorks is at handling all the tricky bits of bends and folds.
For more sheet metal design go to the website of Devon 3D CAD.
Converting a solid part to a sheet metal part.
It is sometimes very convenient to start with a solid part, specially when you have already worked out the shape beforehand. Here is the finished part to get an idea of where we are heading.
The part is similar to a box with two flanges.
I started by modelling the basic shape as a solid. I always try to use geometry in design when I know that the part is symmertical, here about the Right Plane. The sketch is extruded a certain distance either side of the midplane.
Next I shelled the part using the wall thickness I had chosen for the sheet metal.
Using the ‘Convert to sheet metal’ tool I choose one face to be static and choose the edges that will have to folded to form a sheet metal part. The software tool makes a break between the faces and allows you have a lot of control over how the folded faces meet at the intersections.
You can see I have used an overlap feature where two faces intersect. The small gap between edges allow the part to be laser cut from the flat pattern.
Next I add a flange on one edge.
Then I mirror that flange about the top plane.
Then I add mounting holes by extrude cutting 2 holes in each flange.
The ventilation holes are made by cutting one hole then propagating it using linear patterns.
The first linear pattern makes one row of holes.
And the full number of holes is completed by patterning the row up and down the face.
Finally a cable entry hole is added on the bottom face.
And this is how the part is laser cut using the flat pattern from the 3D data.