From the Factory to Our Garage

Stephen Casner, Roadster Owner, 15 de novembro de 2008

In October, Stephen Casner and his wife Karen toured the Lotus factory in England as their Roadster rolled off the assembly line. They took delivery at the Menlo Park store three weeks later. Stephen, who has written several other blogs about Tesla, describes the tour and his first impressions with the car.

Stephen Casner spent 25 years working on protocols and systems for transmission of audio and video over packet networks, starting before the Internet existed and continuing through the Internet Multicast Backbone (MBONE). He was recruited to the Silicon Valley to work with startup Precept Software and its IP/TV product, which was later acquired by Cisco. He is currently a Fellow at Packet Design, working on route analytics. Like Steve Martin and Alec Baldwin vying for the position of most frequent guest host on Saturday Night Live, he felt compelled to write this third guest blog article (after the EV Experience and Handing Over the Keys) after three other people wrote two each.

Last stage of assembly line outside...

On Oct. 13, my wife, Karen, and I visited the Lotus factory near Norwich, England. There we met Glyn Owen, the General Manager of Tesla Motors Ltd., Tesla's UK subsidiary. We had coordinated with Glyn to arrange our vacation around the build schedule of our car, number 33 in the Signature One Hundred series.

..and inside

Our visit began with an interesting discussion with Glyn about the automobile business and especially the past and future of electric vehicles. Glyn then led us through a detailed tour of the assembly line, capped off with a viewing of our finished car waiting for us at the end of the line. (We got to sit on the plastic-protected seats in our car, as shown in the photo above.)

Our car was air-freighted to the US before we returned home at the end of the week. On Oct. 25, we stopped by the Menlo Park store and found our car undergoing its first test drives by technicians after the installation of the 1.5 drivetrain.

On Halloween, we took delivery after two-and-a-quarter long years of anticipation! Rainy weather has limited our driving so far, but I'll try here to give a good description of the factory tour and some first impressions as an owner.

Part of Tesla's office

A Factory Amidst Farms
As you can see in a satellite image, the factory occupies the site of one of several air bases constructed in the farming country of East Anglia during WWII. The runways serve as the straight aways of the test track, and some original buildings remain. The assembly line itself fills the large buildings in the southern half of the site, while Tesla rents office space in one of the buildings in the northern half. Glyn explained that, excluding time for painting, it normally takes about two and a quarter days to complete the assembly process traversing the two build lines, assuming that all goes well. About 12 Roadsters get started down the assembly line each week, and Tesla is steadily ramping up production starts. The number of vehicles finishing the line varies depending on parts availability, quality controls and inspections, planned stops and other factors.

Elise panels ready to paint

Parts converge on the assembly line from several remote sources. Body panels come from France and the chassis comes preassembled from Norway. Those are just the biggest pieces; thousands of smaller parts come from different suppliers.

Each set of body panels is assigned to a particular car and then painted in the color selected by the owner. When we went by, the body panels for an Elise awaited entry into the clean room mounted on a paint trolley. The trolley holds the panels in the same relative position and orientation as if in an exploded diagram of the car. That way the grain of the paint will have the same orientation on adjacent parts as they come together in the finished car.

After the paint has dried, the paint trolley advances to a brightly lit inspection station.

Paint inspection

If the panels pass inspection, they are stored on a parts trolley to feed into the assembly line.

The actual assembly line begins with the prefabricated chassis constructed of extruded aluminum members that are bonded together with orange epoxy and fixed with a rivet that prevents the bond from tearing under stress.

Chassis enters assembly line

In this view down the line, Glyn is explaining to Karen how the chassis rolls in and gets mounted to a cart to move from one station to the next. Note the cloth band covering Glyn's watch; everyone on the line (including us) has to cover watches and belt buckles to avoid scratching the cars. At each station of the assembly line, workers have approximately 45 minutes to pick out and attach additional wiring harnesses and other components as appropriate for the particular car type, then they wheel the cart to the next station.

The chassis for both the Roadster and the Elise accrue similar, but not identical, suspension members, brakes, windshield, rollbar and all the other parts that fit under the body panels. A Roadster chassis skips over the stage where the nasty gasoline engine goes into an Elise chassis. The Roadster glider must wait for the trip to California to pick up its battery pack, PEM, motor and single-speed gearbox. When the chassis assembly is finished, an overhead hoist frame is attached so the chassis can be lifted into a complex jig for the attachment of the first body panel.

Adding hoist frame

This panel covers the area below and behind the door on each side. It requires careful alignment because it sets the reference for all the remaining body components. To get this right in a repeatable process, the chassis is held in one jig while the side panel is held in another, then the two come together and the panel is fixed into place with adhesive and fasteners. In the photo you can see the rear brake rotor and tail of an Elise chassis. Consequently the blue side of the jig is holding the body panel for attachment.

Jig for side panels

Had this been a Roadster chassis, the red side of the jig, which fits the Roadster panel, would have been rotated into place instead. (No association with American politics should be inferred!) After the panel is attached, another jig at the next station brings in the doors so they can be aligned to the side panel before mounting by their hinges. The partially completed car lifted from the door jig and again attached to a cart start down a second line for installation of the remaining body panels and the interior components.

Down the second line

After proceeding through a couple of stations for installation of the body panels, workers at the next station check the fit of all the panels and look for any damage that may have occurred during assembly. We saw Signature 100 car number 50 at this station. Cars start down the assembly line in numerical order, but they don't always exit that way.

Inspecting car #50

That is because a car may be taken out of line to correct a problem. This is a good thing -- if a problem can't be resolved properly in the time allotted for an inspection station, rather than blocking the assembly line it is diverted to a holding position where the problem can be fixed. There is a "build book" that travels down the line with each car.

Installing the interior

It records any problems found at each stage so that at the end they can be fixed and verified. The collection of these build books serves as a reference for the manufacturing engineers to refine the process to avoid recurrence of the problems. As the car continues down the line, the seats and other interior components go in. This is a critical stage for owner satisfaction since the driver observes the cockpit at close range on every trip, so it would be a good assignment for workers with perfectionist tendencies. At the last station the wheels go on and we have a car! Well, most of a car. Since the battery pack and PEM are not installed, the 12V systems have no power, but leaving those systems untested until the powertrain is installed in California would result in higher repair costs and longer delays if something wasn't right.

Completed assembly

To avoid this, Tesla engineers designed a PEM simulator with a multi-headed umbilical cord that connects to all the necessary 12V systems. After the functional test, completed cars queue up to ensure there are no remaining problems after reviewing their build books. This is what we've all been waiting to see: Tesla Roadsters produced not just one or two at a time but in bunches.

PEM simulator test

Looks like a Roadster traffic jam! Each Roadster has two more test stations to pass. The first is a test on the dynamometer. Whereas an Elise gets to exercise its engine while the dyno provides load, the Roadster sans motor needs the dyno to simulate motion for testing the brakes and bearings. The second test blasts the car with water to check for leaks -- with the soft top on, of course. The last gauntlet is the quality control inspection, again under bright lights, where different teams check the car for imperfections.

Several completed roadsters

This area has its own paint booth for repair of paint problems or damage during assembly, although such cases should be rare. I was impressed by the number of inspections I saw. The result shows in the positive comments we've seen in the blog and owners' forum about fit and finish. Glyn introduced us to Chris who is in charge of Final Acceptance for Tesla and appears to be doing his job well.

Finally, with protective white tape applied, a finished car is ready to ship.

Ready to ship

Our car was waiting at the end of the line in a special booth where a sample of finished cars from the line get a final inspection by Tesla employees from the perspective of the customer. Glyn told us that at this point in the ramp-up of Roadster production all of the cars are receiving that inspection, but that later as confidence in the process has increased it won't be necessary to include this inspection for each car. Paraphrasing a comment by "Jeff" in the Owners' Forum, the Signature Green color is elegant, the silver is sleek, but the Radiant Red is gorgeous.

Our car #33

I have not seen any Roadster in the factory or showroom that I wouldn't want to have, but I'm very happy with the color combination my wife and I chose.

Karen wanted to give Chris a hard time and managed to find a fingerprint on the glass, but Chris quickly wiped it clean.

Karen checks over the car
with Chris and Glyn

As exciting as it was to see our car, even more fun was the drive around the Lotus track in a validation prototype Roadster with the Tesla test driver, Sean, at the wheel. I was kicking myself later that I did not think to use the video function on my camera to capture a bit of it for you all. On the other hand, considering the cornering at a good fraction of 1g, I probably would not have been able to hold the camera steady anyway. I think we got up to about 115 on the straight, then Sean braked hard for the chicanes, narrowly missing the rabbit running across the track.

This car sticks like glue in the corners. Coming around to the skid pad, he intentionally threw the car into oversteer to demonstrate recovery. I'm glad it was his tires left on the asphalt and not mine.

Batteries not included!

I enjoyed this immensely, and I only wish I had the time and opportunity to develop some of that driving skill for myself. What I took away from this demo ride was that there is a significant margin between this car's limits and my own. Our visit to the Lotus factory made for a great vacation, especially when coupled with unexpectedly nice weather for October as we drove through beautiful countryside around Norfolk, Suffolk and points south on the opposite side of some very narrow roads. I thank Glyn and others in Tesla Motors Ltd. who were most generous with their time for our visit. Glyn even presented us with photographs of our car as it was on the assembly line to complete the record.

Taking Delivery
On Halloween afternoon, we finally got the call saying that our car was ready for delivery with drivetrain 1.5 installed. So what are my first impressions?

Sorinne explains the controls
to Steve and Karen

This car strikes the right balance: it is a sports car that clearly communicates back to the driver, not a luxury car that tries to do the driving for you--yet it looks and feels good, not spartan. Everyone who sees it comments on the car's beautiful styling and the fit and finish. The few so far who have had a chance to go for a ride have also been impressed by the performance.

Making sure the battery
is really there

The "pedal feel" is excellent (see my first blog article for this term). I was concerned that the regenerative breaking would not be as strong as I like, but it is as strong as the "B" position on the RAV4-EV and it continues to slow the car all the way down to the creep speed. As a result, much of the time I don't need to touch the brakes until just before stopping if I'm conscientious about the distance to the car ahead. There is also none of the RAV4-EV's jerk in the transition from acceleration to deceleration, so the cruise control holds speed steady and smooth on hilly I-280.

I have a couple of gripes with the cruise control. First is that by design it works only down to 30 MPH. I need 25 MPH to help me stay legal on the many 25 MPH streets and school zones around home that are monitored by cops with radar guns. My second improvement would be to bring on regen braking more gradually when cruise mode is released with the "O" (cancel) button so the driver has time to find the right deflection of the accelerator to take over smoothly. When the brake is touched to release the cruise mode, having regen come on full as it does now is a good strategy.

This article is long already, so more will have to wait for another time after a chance for some mountain driving.