On March 1, 2019, Tesla honored Elon Musk’s commitment at the launch conference three years ago: the official launch of the Model 3 Standard Edition, which was priced at $35,000. However, research around this car continues, what are the engineering mysteries behind this model that has been considered impossible to make money since its birth?
On the afternoon of March 13, we interviewed Sandy Munro, founder and CEO of Detroit-based engineering consulting firm Munro & Associates in Shanghai.
Munro purchased two Model 3 and spent a total of 6,600 hours on reverse engineering and costing Model 3. Prior to founding Munro & Associates, he was a Ford senior automation and assembleability specialist and head of NASA’s Advanced Manufacturing Center.
The habits of years of engineering experience have led him to pursue science and rigor. He is happy to talk about engineering innovations that are eye-catching, and to criticize low-level engineering mistakes.
Body-in-white, Body-in-white, Body-in-white.
Tesla tried to improve the safety of the Model 3 by using a steel-aluminum hybrid chassis frame, but in fact, the Model 3 tiled battery in the chassis has greatly increased the rigidity of the chassis. And these painstakingly combined steel-aluminum frames give the Model 3 a completely negative effect.
The steel-aluminum frame makes the assembly of the Model 3 very complicated and difficult. The number of parts is too complicated and the workers need to align the gaps, which makes the manufacturing difficulty greatly increased.
At the same time, it also led to an increase in the quality of the Model 3, affecting handling performance and battery life.
In addition to the bottom frame, at the rear of the body-in-white, multiple parts of the aluminum trunk are assembled from rivets and welds, instead of the more common and lighter, lower cost fiberglass trunk.
The rear rim position of the Model 3 body-in-white is made up of 14 fittings that are riveted, sealed and welded. If it is a traditional car, this position requires only one stamping accessory.
The Model 3 integrates five completely different connections and a large number of complicated and unnecessary accessories on a body-in-white. In Munro’s view, this is the embodiment of Tesla engineers’ “sports-making cars.”
Obviously, the Model 3 achieved good safety crash test results through over-design of various parts. It is the five-star safety model with the lowest probability of injury tested by the National Highway Administration. However, this over-engineering has broken the balance of other Model 3 indicators.
The manufacturing cost of the Model 3 is $2,000 higher than the BMW i3, and most compact or economical cars have a profit of less than $2,000.
Can the engineering error of the body-in-white be remedied? Can this problem be improved on Model Y?
“I’m pretty sure you’ll see improvements on Model Y.” Munro even said that if he was the Model 3 project leader, he would immediately lead the engineering team to make improvements to the Model 3 body design.
After completing the disassembly analysis of Model 3, the Munro team conducted a brainstorming of “Redesigning Model 3”.
They asked questions about each design of Model 3. First, is this part reasonable at this location? Second, can this part be made of better materials? Eventually the Munro team proposed 40 improvements to the Model 3 body. These improvements can significantly reduce the manufacturing cost of Model 3.
Munro’s philosophy is to encourage car companies to use spring fasteners and belts as little as possible, which can cause some quality problems. If these parts are eliminated, the reliability of the product will be improved, the cost will be reduced, and the assembly difficulty will be reduced. For example, this metal bayonet structure is a kind of fastener that Munro is more admired.
The Munro team made a total of 227 points that could be improved, and then sent these ideas to Tesla for reference.
How does Elon view Munro’s point of view? After Munro expressed his criticism of the Model 3 body-in-white, Elon forwarded reports that the Model 3’s body design could indeed be more concise, but most of the added weight is based on a higher safety design than other models. .
All the problems are concentrated on the body-in-white, which is the biggest mistake of Model 3.
“Except for all the work left by the body-in-white Tesla is doing very well. Tesla’s product philosophy and R&D and design have very talented ideas.” Munro recalled his conversation with Elon.
Munro: “Model 3’s mistakes on the body-in-white are really impressive.”
Elon interrupted him: “I have fired the body-in-white design engineer.”
Munro told Elon: “You fired too late.”
If Tesla can do the design of the body-in-white from the beginning, other car companies have no chance to catch up with Tesla. If the Model 3’s body-in-white structure is more reasonable, its body quality will be comparable to that of the BMW 328i.
Tesla sent a statement in response:
“The Model 3 dismantled by Munro was launched in 2017. After that, we have greatly improved the manufacturing process, although there is still room for improvement, and our data shows that the quality of Model 3 is rapidly increasing.
We are very concerned about streamlining and adjusting the number of parts and body manufacturing processes. All crevices and offsets on the body panels have been reduced by 40%, especially in the trunk, taillights and body tail gaps. Today’s Model 3 has been commensurate with the door panels of the same class of Mercedes-Benz, BMW, and Audi, and Tesla will continue to improve manufacturing precision.
For the balance of white body over-design affecting other indicators, Tesla’s response is that the safety of the owner is more important than any indicator.”
It’s hard to say that Model 3 is “the most innovative” in engineering. Model 3 has a lot of engineering innovations. Munro’s statement is that no other car company can make a similar product in the moment.
The Model 3 has the most impressive three points. The first point is the battery pack. The Model 3 battery pack is the industry leader, Samsung SDI, LG Chem, and the technical capabilities of any company can’t reach the height of Tesla.
The 2170 battery module is assembled from a highly accurate robotic line. Each individual cell is connected to another cell and a separate cooling tube. A unique low-heat ultrasonic aluminum wire bonding process connects each cell to The battery balances the battery, which is a very precise process.
There is only a 0.2 millivolt gap between the cell and the cell. Highly accurate cell consistency far exceeds the technical capabilities of all other power battery companies.
The second is a permanent magnet motor. The Tesla permanent magnet motor uses a neodymium-iron-boron magnet with a Hall effect. This magnetically strong permanent magnet forms a super-strong magnetic force at one end of the magnet through a unique Halbach array. At the same time, the magnetic force at the other end is reduced to near zero. This is a very talented innovation with a very high technical content.
Comparing the Model 3, i3 and Bolt motors, you can see that the Model 3 has the lowest motor cost, weight and volume, but the highest performance and efficiency.
The third point is electronic electronic control, Tesla Model 3’s electronic circuit design is more advanced than any other car.
The Model 3 central controller board is a bright spot, and our team of engineers has repeatedly analyzed and will have new gains every time.
The whole board is full of...all the new things that come out with this board, this board like nothing else, this is why I say that 10 or 20 times better than anything else, not 20% better, but 20 times better.
Many people are concerned about Tesla’s auto-assisted driving system Autopilot. How do we disassemble the board for analysis? First, we will list the components on the board, and then mark the name, process, and cost of each component separately, and finally get the circuit design capability and corresponding cost required to integrate the whole board.
The components of the front and back sides of Tesla’s board are very compact, with very high integration and design process. Obviously, Tesla has gathered many talented electrical engineers, and the Model 3 central controller board is so complex between the phone board and the rocket board.
In a traditional car, three to four physically independent boards are integrated into a complex circuit board, and the components without solder joints and extremely miniaturized components achieve volume reduction and cost reduction.
Through the complete dismantling of Model 3, we have come to the conclusion that Tesla is far ahead of other car companies in terms of battery basic technology, motor basic technology and electronic basic technology, and some circuit board processes have even reached military-grade product‘s level.
In addition to Model 3, we also shared with Munro his views on the BMW i3 and Nissan Leaf, the next generation Model S/X, NIO ES8, and China’s electric vehicle industry. The fun Muro has a huge presence in the electric vehicle industry. Passion, did not evade any question, we will organize all the Q&A lists as follows, Enjoy it.
Q: The Model 3 will be put into production in Shanghai, How much the cost of parts, labor and manufacturing can be reduced?
A: I can’t give specific figures on material, labor, and manufacturing cost reductions. But according to our calculations, the gross profit margin of the standard version of Model 3 in China can reach 23%, while in California, the figure is 18% . Considering that not many people will buy a $35,000 bare car, most people will increase the price to around $44,000. The actual gross margin of the Model 3 Standard Edition will be even higher.
In addition, many of Tesla’s features are pre-embedded hardware activated by OTA (paid unlock), which makes the gross profit margin of some Tesla models continue to increase after delivery. This unique business model is an unmatched advantage for other car companies.
Q: In what ways will the next generation of Model S/X be improved?
A: The Model S/X is positioned as a luxury model, which determines that its market demand will be much smaller than Mdoel 3. A mainstream luxury car company has commissioned us to dismantle the Model S/X, but we thought that the two cars (compared to the Model 3) did not have many bright spots in the initial observation, and it is not worth exploring.\
Because Model 3 has huge market demand, and larger scale effect will amortize R&D investment, Tesla has invested a lot of research and development power in this car, including a large number of first-time commercialized cutting-edge basic technologies and development of proprietary molds and many more.
Regarding the unreasonable design of Model 3, some internal news I heard said that Tesla has already started to improve, and many of the suggestions we made will be applied immediately. This is my supplement to the question just now.
Continuing with the next-generation Model S/X, Tesla will obviously do some regular upgrades in styling, interiors, and workmanship. However, in terms of the application of cutting-edge technology and the development of new molds, from the perspective of capacity scale, the upgrade of the new Model S/X to Model 3 will not be as large as the upgrade of Model 3 to the old Model S/X.
Q: How do you view the smart electric SUV ES8 from China’s new car company NIO?
A: We haven’t done the disassembly and analysis of the ES8 yet, but from the public information and the information I learned (Munro once went to see the real car), the ES8’s product completion, manufacturing precision, workmanship, and craftsmanship are not bad. NEDC’s 355 km battery life data also sounds OK, I hope there is an opportunity to do a practical test.
Q: BBA has also introduced pure electric products. Which aspects of Model 3 and BBA are more advanced? What aspects are not good enough?
A: From the perspective of product innovation, BBA’s pure electric vehicle should not be compared with Model 3. The Model S comparison is more reasonable; From the sales point of view, BBA’s electric vehicle sales are not too bad, but will not create Model 3 North America such as sales miracle; From a commercial point of view, BBA’s current electric car is difficult to make profit, and Model 3 is one of the few very profitable electric cars.
Q: In the process of transforming the fuel engine powertrain into a pure electric powertrain, what new imagination space is brought to the engineering design of the vehicle?
A: First of all, what I want to say is that you should never build an electric car with the concept of traditional car making. Many times engineers use traditional ideas to solve problems and use some inherent ideas. But electric cars bring a lot of imagination, which is completely different things, and can’t apply past experience to solve new problems.
A typical example is the Chevrolet Bolt. Bolt is based on a fuel vehicle platform. Bolt and General Spark are based on the same platform, but Bolt’s three electrics are doing very well. How did Chevrolet do it?
They hired LG. LG made the battery, LG made the motor, LG made the gearbox, and LG made the entire powertrain. Only 25%-30% of the components of the Chevrolet Bolt were developed by GM engineers, and all the components related to “Electricity” were handed over to LG, a company that understands the design of the three electric products.
Q: Where is the BMW i3, Bolt doing Bitsla better, and it is worth Tesla to study?
A: Chevrolet Bolt The excellent thing is that the cost control of the steel frame body is very good. One of the disadvantages of steel and aluminum construction is that the cost will be slightly more expensive. The BMW i3 has a lot of lightweight points for the whole car, such as carbon fiber body.
Engineers are accustomed to thinking that carbon fiber bodies are light but costly. But in fact, with today’s technology, when the car sales can exceed 70,000, the cost of carbon fiber is actually acceptable, not what everyone thinks.
Q: Compared with traditional car powers such as Germany, the United States and Japan, what are the competitive advantages of China in the era of electric vehicles?
A: In general, I am very optimistic about China’s pure electric vehicle industry. I have been continuously observing the attitudes of government leaders towards new energy vehicles. The attitude and determination of a national leader will greatly affect the development of the entire industry. Teresa of the United Kingdom, Merkel of Germany, and the Japanese Prime Minister of the United States….. At present, there is no Chinese leader who is far-sighted.
It is very wise for Chinese leaders to formulate policies in light of the state of the country’s energy industry. He understands what kind of future China needs. By 2020, China will lead the entire electric vehicle industry.