There is a very interesting new article just published by InsideEV, a German engineering firm analyzed the Model Y cast frame structure and came away very impressed:
Tesla Model Y May Have Bigger Cast Parts Than Expected
“The casting process must be definitely very well advanced because the size and weight of the cast parts are beyond what is known from today’s auto parts. The process could be done with HPDC (High-Pressure Die Casting) on a cold chamber pressure casting machine with vacuum support to avoid casting defects such as pores, bubbles, cracks, etc.
Our rough assumption is that the rear structural part could weigh around 40 to 45 kg. As a reference: the cast rear long member of the Audi A8 is weighing approximately 10.5 kg.”
I.e. the Model Y is way beyond the current casting technologies of German automakers.
“For the rear body structure, we assume the closing force required would be above 6.000 metric tons. Usually, the maximum shot weight for aluminum alloy parts is around 10 kg, due to machine limitation in closing force capacity. The standard closing force is around 1.500 to 2.000 metric tons.
Only very few machine suppliers worldwide have the experience to build cold chamber casting machines with 4.000 or a maximum of 5.500 metric tons of closing force. Therefore, the machine at Tesla must be a special custom-build and quite gigantic.”
They estimate significant reduction in Body In White manufacturing time and costs:
“The body assembly shop most probably consists of two frame lines, two body side subassembly welding cells and a BIW (body-in-white) closure mounting and finish line. That would be roughly only 60 percent of a conventional body shop.
The total production time of a Model Y body-in-white compared to a conventional stamped steel body will be substantially lower. Considering the net process time for the underbody section, only the casting would eliminate between 1.000 to 1.500 weld spots, at 5 to 7 seconds each. That would total at an approximately 120-minutes net process time-saving.
If Tesla is able to manage the production process with high quality, production costs will be definitely lower than Model 3’s. Guess what would happen if the full-body frame casting machine would work as shown in their patent application…”
This means significantly higher margins on the Model Y - and also explains how Tesla was able to build the new Model Y body line in just a few months in the limited factory space of Fremont.
