The Tesla Factory: Birthplace of the Model S

Gilbert Passin, VP, Manufacturing, June 16, 2010

The Model S is the premium sedan evolved. It will raise the bar of vehicle efficiency, meet the highest standards for safety, and provide more cargo space than any other sedan. It will be as beautiful as it is functional. Here's how we will build it. The Model S will be produced at the new Tesla Factory in Fremont, California. Everything from body panel stamping to final quality testing will take place at the Tesla Factory. We will also work to set environmental benchmarks for energy efficiency and emission levels.

When building a car, most manufacturers follow a consistent production flow. We will use the same process, with innovations at each stage.


The Model S will begin as sheets of aluminum. The sheets will be placed in a hydraulic press machine and stamped into 3-dimensional fenders, hood panels, doors, and roofs. Stamped aluminum saves about half the weight of steel and the decrease in weight enables us to increase overall vehicle efficiency. Even before we finalized the factory location, we secured machinery and items we'd need to quickly bring the facility online. Our hydraulic press line is of the finest quality and we expect to use it for decades. The press line will produce body panels you can see and structural features you can't. The remaining body stampings, castings, and extrusions will be produced at outside facilities and shipped to the factory for assembly. Sub-Assembly The workers in the Body Sub-Assembly Shop are responsible for joining the stamped pieces together at stations. It is far more efficient to compile groups of components into assemblies instead of building a car piece by piece on a single production line. The smooth outer panels that give the Model S its beautiful lines will be welded to the inner structures that give the car its strength and safety.


Next, the prepared sub-assemblies are moved to the Body Framing Shop. Robotic arms pick up sub-assemblies from nearby racks while other arms move in with glue, weld, and rivet guns to seal and join the parts. The doors, hood, and trunk lid are hung on the main frame. The roof frame that will hold the bright panoramic glass panels is then attached. At this stage, precision is paramount. Once framed, the welds, holes, and gaps are checked for imperfections. The perfected structure that leaves the Body Framing Shop is referred to as a "body-in-white." The body-in-white represents the primary structure of the car and is critical to driving dynamics and occupant safety - it is our goal to achieve a 5-Star Safety Rating from government crash tests. The complete structure is now ready to be painted.

A car's color says a lot about the driver, and it is at this stage that the Model S begins to develop its character in a four step paint process including preparation and three coats of paint. The Model S paint process will differ from traditional paint in an effort to reduce emissions. The innovative paint process will use powder coating for both the primer and clear coat layers. The Model S will be one of the first cars to employ not one, but two layers of powder coating. Traditional liquid paints contain harmful VOCs. By using powder paint, we will substantially reduce factory emissions while producing class-leading paint quality. To paint, the car will be attached to an electricity source and grounded. The positively-charged paint will be sprayed with paint guns. The charged particles are electrostatically attracted to the car and spread evenly. Once applied, the car travels on a conveyor belt through a 350 degree oven to cure the paint. Between the primer and clear powder coats, the color layer will be applied. After the three paint layers are applied, the car will be wet sanded to ensure a flawless surface.

Final Assembly

Once the final coat of paint is polished, the car moves to the final assembly area. Here, it transforms from a shell of sculpted, painted aluminum to the premium sedan you've been waiting for. The movable pieces of the car (the doors and trunk lid) are removed and delivered to separate assembly stations for further work. At a door assembly station, for example, wiring is fed between the outer panel and the inner frame, the handles are attached, and the premium leather pieces are fastened. Other assembly stations work on the dashboard, trunk lining, and other pieces. The parts deepest within the main frame of the car are attached. Next, the interior sub-assemblies are installed: carpet, headliner, console, dashboard, seats, and the steering wheel. Airbags are installed in key locations to protect occupants in the event of an impact from any direction. The doors, once appointed, are reattached and adjusted for fit. But, what would the Model S be without the state-of-the-art powertrain and battery systems? With far fewer moving parts than an internal combustion engine, the motor, transaxle, inverter, and rear suspension system will be contained within one sub-assembly that can be bolted into the Model S in one step. The liquid-cooled battery pack, with quick release fluid connections will be installed in a matter of seconds. The battery pack provides the final structural element to the body. With this engineering feat, you'll be able to quickly swap an empty battery for a full one, should the need arise on long road trips.

Quality Testing
Before delivery, the car must go through quality testing. Typical quality tests consist of a "rolling road" (a device that mimics driving on real streets), a water test to check for leaks, and an inspection station that ensures all components are installed to standard. Instead of wasting gallons of water to perform the leak test, we will instead employ ultrasonic waves inside the car as a device on the exterior detects escaping waves. With this scientific fluid ingress test system, we will save precious natural resources. At the end of Quality Testing, your Model S is ready for delivery.