# Manufacturing metal sheets of a car frame

1. Oct 29, 2012

### Jay_

I saw this video of BMW car manufacturing plant on YouTube, and they showed how the robots fix metal sheets of various shapes onto the main frame ("skeleton") of the car.

I was wondering: How to they make those metals in those particular shape.

On one side there is the frame work, and the pieces on the left have to be identical (but symmetric!) to the ones on the left. They have to be of the same size and symmetrical in shape before the whole thing is welded together.

And then there is the sheets of metal which are fixed ON the frame. And all of this is real good metal work, you have a sheet of metal that is a complex shape. Like if you see a Lamborghini for instances, those metal shapes are not easy to replicate identically.

I know they use CAD software, but how do they PHYSICALLY get that shape. I imagine that if you start from a sheet of metal, beating it wouldn't bring the shape to be "smooth" as it appears. My guess at this point is they heat it a little and then shape it the way they want. But still, how is it done so symmetrically and perfectly

Lastly, after all the sheets are made, the whole thing fits perfectly on the skeleton. So how is it all done? The frame shapes, the sheet shapes and the perfect combining of the sheet shapes on the frame.

Thanks :-)

2. Oct 29, 2012

### Simon Bridge

There are machines that stamp them out and weld them together - robots.
The whole thing is done with highly accurate machinery.

3. Oct 30, 2012

### Jay_

I have seen that. But any idea how curved metal sheets get stamped out without a single wrinkle on them? If anyone could send a link to a video or give me the name of the process of how the sheets are made, it would be great.

I know how they weld the whole thing together. What I am puzzled about is how they physically create the sheets which they weld together :-D

I imagine the calculations are not so hard given that there are a variety of CAD tools. But bending the metal sheets without wrinkles is what I am a little puzzled about.

4. Oct 30, 2012

### pantaz

Wrinkling can be a problem in metal forming, and can often be found in non-structural parts (and when appearance is not an issue.)

Plenty of videos and detailed explanations can be found by searching "metal stamping", "deep drawing", and "hydroforming".

5. Oct 30, 2012

### Jay_

Seems good. Look probably look into these words (the processes) in more detail. Thanks guys :-)