How NOT to draw a sheet metal product. AVOID this mistake!

Every time we want to draw a model, we need to take into account how it will be produced. If not, you can end up with a beautiful model that is useless to manufacture the product. We don't want that, don't we?

How would you draw the following sheet metal product?

Simple aluminum can, as an example

I took a simple aluminum can as an example.
How will you draw it?
The two most common ways would be:

• Make a solid drawing and use the shell feature 
• Use the sheet metal complement 

If you don't see the difference between the two options at first sight, don't feel bad, you came to the right post.

 Why should I use the sheet metal complement?

If you really want to manufacture the sheet metal product, you must know that building a solid chunk in Solid Works and throwing some dimensions over it won't give you the expected result.

When manufacturing a sheet metal product, one or more of the following will occur:

1. The sheet of metal will deform, changing its size
2. The thickness of will most likely change
3. The product will consist on multiple sheets of metal

The most important result that we need is the resulting sheet.
Solid works calculates the needed sheet before starting performing all manufacturing processes on it.

As an example..

Look at the following nonsense sheet metal product

Ugly and useless

Unless it is is manufactured by foundry, that is worthless. We need the initial sheet of metal:

The unfolded sheet allows you to produce the product

The unfolded model takes into consideration the change in size by folding and working on the sheet.


To be able to draw your model in those terms, you should think on the manufacturing process.
For example, in the case of the aluminum can, I recommend you to see a video and see, as always, that the model won't be as simple as it seems. It takes multiple manufacturing steps to end up with the aluminum can, and if we consider the little opening metal piece, three parts constitutes the model.


At this point, maybe you just want the model for another reason, like rendering an image for marketing purposes.

The WRONG way of modelling the aluminum can

As stated, if you don't need the model to actually produce the sheet metal product, then, go ahead and build a normal model, with normal operations:

As always, insert images of the aluminum can in each plane. In this case, top and side.

Start drawing half the silhouette

After drawing half of the silhouette, perform a revolution extrusion. Don't forget to draw the axis to reference the revolution feature.

Then, continue with the top view. Insert the image
By the way, you can insert it in Tools, Drawing Tools, Image.

Auxiliary circles are drawn over the image of the top plane

Here, the auxiliary circles will allow you to draw from lateral plane, but still accessing the extreme points of the circle, as references.
The surface is shiny and has many changes in radius. Its troublesome, so don't get frustrated. Make an approximation, as I did, unless you want to cut the can perfectly in half, so you have the real section of that part. Too much of a problem, it doesn't make a functional difference.

Drawing the section to perform the revolution cut

You can draw lines to help you with the depth of the drawn section. That, together with the circles in the top plane, you can make an approximation of the side section

 

 

Result of the metal can after the revolution

 

 

 

 

Make use of the rounding feature in every sharp edge that is rounded. It is a really easy process.

Draw the following sketch using splines. Then use an extruded cut.

Perform an extruded cut from sketch

The model is almost complete
Draw the little piece of metal that allows to open the can and extrude it. (Does it have a name?)

Drawing the nameless piece

Then you should use the shell feature to end the drawing being an empty can and not a piece of metal.
In this particular case, SolidWorks couldn't build the operation for some reason, so I will search more in detail why is this happening.

Apply the polished aluminum appearance and insert an image to the side, and the can will be complete
The hole in the top is optional: is it open or not?

Final result of the sheet metal product

To insert the image, enter en appearance and select the wanted image. Then, adjust the size and position. It is really straight forward.

Inserting and adjusting size and position of the desired image

You can always render the final image if you want!

I will upload the sheet metal procedure to model the can when I have some time.

Regards