I just tried various searches for auto body fabrication - they all end up talking about restoration of antique cars or doing “one-off” fabrication.
Somewhere, somebody is stamping and rolling bits of sheet steel which end up being welded together to make a car.
The large panels - hoods, roofs, fenders, trunk lids, etc., are relatively easy - they need to be easily removed/replaced for repair.
But where do all the pieces which get welded to form door posts, etc. come from?
Could I hire out everything except the large panels and have a completed car?
I remember a summer job in a tiny sheet-metal plant. Stamping and welding, a bit of painting.
I also know that cars used to come as running chassis with cowl - the customer took the thing to a body shop and got the body style desired. Hence the Cadillac tag line “Body by Fisher” - GM bought the Fisher (very nice) body fabricator.
Some of this has to survive.
In some form.
Tesla released a clip of robots grasping highly-fabricated bits of sheet steel, holding them in alignment and spot-welding them. This is a tiny part of the picture.
Do you mean for a standard production vehicle or your own design?
The production vehicle uses dozens of very heavy steel “dies” that are a mold for the part, both inner and outer mold. A cut-to-rough-shape metal panel is placed between the dies and many tons of force press the dies together. Sometimes hundreds of tons for a large panel.
The design team has already designed each separate part over a few years. Other people make sure they all fit together and don’t rub when doors are opened, etc. Every part, and each sub assembly and the entire assembled body undergoes finite element computer testing to examine stresses, both from normal use and during accidents.
If it is your own design, you have to do all that… If you watch any car shows, think Chip Foose or Boyd Coddington. Many of their vehicles are highly modified production bodies, but they are capable of taking a bunch of sheet metal and turning it into thing of beauty.
I’ve done enough minor sheet metal fabrication to realize just how amazing a craftsman like that is. Just sheet metal, an imagination, an English wheel and planishing hammer and lots of time. I have some how-to videos where the instructor fabricates a complete, single car part during the course of the video.
In between the two extremes is how a lot of cars were made over the years. Hand hammering each fender over wooden bucks with lots of skill is much faster than just forming by hand and helps makes each car more or less the same.
I’m restoring my Triumph TR3 now and get into fabrication somewhat, although most of it will be repairing rust holes, replacing floors, etc rather than forming from scratch. But I certainly can make the simpler parts with my sheet metal brakes, shears, benders, etc. Here is a link to one restoration where the frugal builder takes apart two cars and makes one, often removing piece after piece, repairing or making a new one, and welding it into place, all the while keeping ALL the parts of the body registered together properly. Even that is WAY WAY faster than starting with a sheet of metal.
Here is a link, the smaller photos may not enlarge unless you register but if you are serious, that only takes a moment and doesn’t cost anything. He is over 100 posts and just skimming through and looking at some of the photos gives an idea of the complexity.
I’m just wondering if there are shops which can either:
Fabricate the individual bits and ship them to the “Car Maker”
and/or
Take those individual bits, align and weld them into either a complete door sill, floor frame, post, whatever?
The tiny fabricator I saw couldn’t assemble anything larger than a Sub sandwich. I was the one who welded the 3 small bits together.
So: Why can’t Tesla, which wants to ramp up production, able to call up a shop and have at least 20% or so of the 100’s of bits either pre-made and/or pre-assembled? Those robots are likely used by several different companies in several different industries.
I’d expect someone to be able to have a dozen or so machines easily configurable to do this work.
Theres a company in Austria that will do contract car manufacturing. They built the Rapide for Aston Martin until AM decided the quality wasn’t good enough. Is this the sort of thing you mean?
Only for niche, small volume companies like Morgan and maybe Lotus. For anything mainstream, rapid assembly is the expectation and every sheet metal part comes out of a series of stamping/forming presses.
Short answer: I wouldn’t “expect” that. Having a dozen or so “machines” just lying around waiting for work isn’t exactly how the market works. Machinery might be similar across industries and business, but there is usually some planning and modification involved in many things. “Easily configurable” is also rather optimistic.
Body parts are not made by robots. Here is a short video making one part. That 100 ton press costs a lot. Each of the dies that form the inside and outside of each part are carved from solid tool steel blocks and polished like a mirror. That is another huge sunk cost before you can make one part. Today that process of making dies is mostly CAD milling machines, but traditionally each and every die was hand made by tool and die makers.
So yeah, AFTER you have all those dies made, you could bid it out to a company to make them. But every part has to be designed. They are often very complex. Just the simple inner body parts for my TR3 are easily made by stamping, but very difficult by any other process.
Actually, if you were making your own body, it wouldn’t be a uni-body situation. It would most likely be a traditional body-on-frame where the chassis provides the strength and a place to attach the drive train and suspension. The body just has to look good.
And that body is often supported by a tubing inner structure, or even wood. Morgans are still built with a steel chassis with a wooden inner frame over that, and the body panels draped over the wood frame.
We haven’t mentioned stereo lithography (Oops, I mean rapid prototyping. Oops, I mean 3-D printing. So how old I am?)
Now that is an area where someday you might be able to hand over the CAD files (you still have to do the entire design process) and a room full of large 3-D printers can form all your inner body parts. But the strength of thin metal parts is not there right now. And the surface finish may never be good enough for the outer panels without finish machining and polishing.
Stamping is such a simple method. Bam! Another perfectly formed, smooth part ready for assembly.
As I said, I am quite aware of how sheet metal gets formed - I am aware of some exotica such as hydro-forming, as well as tool and die fabrication (do Tool & Die Shops still exist?).
That shop did some work for Ford. During a strike, Ford sent in scabs to pull the tooling (owned by Ford) from the shop.
So - at one point, some of this was contracted out. That tiny shop made parts for Ford (and window fans and humidifiers for Sears).
The trend is toward ever-more generic robots which can be quickly configured to perform multiple tasks. No more huge, specialized machines to do one specific thing for one type of product.
Maybe I’m just looking too soon - someday, it will all come down to 3-D printing and the only difference between an auto part, an airplane part, or toy figures will be the programming and the stuff fed into the nozzle(s).
You hire a lawyer. Virtually every component is protected by a patent, and you can’t fabricate a part with a similar design. Unless all you’re talking about is a sheet-metal shell.
My grandfather worked as a civil engineer for a public utility until he identified a line of products he could produce for design implementation by contacts he had made from the inside. That would be one way in.