In a recent video at GM’s YouTube channel, Gerald Johnson, the Executive VP for Global Manufacturing and Sustainability, gives us a tour of GM’s EV factory and introduces us to the people who work there. This video is part of a wider “Competitive Advantage” series featuring Johnson, which is also worth checking out if you’re trying to follow or invest in the EV industry.
The video starts out with an interview with Cathy Staelgraeve, the plant’s assistant director, and the end of the Hummer EV assembly line gave an interesting backdrop. Staelgraeve has been working in automotive plants for decades, and her first plant job was working as a summer intern in 1995. She’s a mechanical engineer, and has a degree, but like many students, she didn’t see herself ending up working in automotive plants. But, she seems to really enjoy this line of work.
She thinks STEM students need to think about the hands-on work they can get into. The book work may seem boring, but the real world work can be a lot more stimulating.
Factory ZERO isn’t new. It’s been a GM assembly plant for decades, but got a complete makeover in 2019 to prepare for EV manufacturing. Now, 1900 people work at the plant, and they’re still growing as they build more models and expand sales of those they’re putting together now.
The first thing Johnson and Staelgraeve show us is the Leica scanner. Leica is a company with a long history in the photography industry, and this is an extension of that work. GM uses Leica’s technology to give each vehicle’s basic platform a detailed robotic 3D scan to see how it measures up compared to the design it’s supposed to match up to. Nothing mass produced is ever a perfect copy, but the bones of the vehicle need to be within normal limits if the rest of the vehicle is going to go together well and perform.
Mike Woods, a Six Pillars Quality Lead, shows us all about how the machine works. Old assembly processes would take six hours to measure a frame/body and make sure it’s all within specifications, and this gear can measure everything up in only two hours. It also gives technicians a color map, showing how far off the frame is at every point. While they don’t explain this in the video, this process helps keep the line running more by spotting production problems early, hopefully before they’ve made a bunch of bad copies.
The Marriage of Battery & Vehicle
Here at GM, we’ve given GM a lot of crap for the heavy and bloated Hummer EV. It’s got a huge 200 kWh battery, but only gets around 330 miles of EPA range. Why? Because the vehicle’s total weight is around 9,000 pounds. A big battery pushing around a lot of weight equals not a whole lot of range. But, this is GM’s first electric truck and it’s their first Ultium vehicle to land in customer driveways. Things are likely to improve as more Ultium models come out that are more focused on efficiency than a Hummer.
One of the cool things we got to see in this video was these huge battery packs getting put into the bottom of vehicles. GM calls this the RESS Battery Marriage Station. RESS stands for Rechargeable Battery Storage System (in other words, a battery pack). Keeyana Hicks, the operator of the machine and GM’s battery-vehicle marriage officiant, shows us all how it works.
She first has to check the plugs on the battery pack to make sure nothing got messed up earlier in the process, and then work a machine that loads the battery pack (a truly heavy one) onto a lift.
Cathy points out at this point that this is analogous to the “chassis marriage” manufacturing step in ICE manufacturing plants. Instead of putting a drivetrain and possibly a subframe and suspension components into a vehicle, this step puts battery packs into the EV in much the same way. Like in many ICE manufacturing processes, the RESS comes from a different plant and gets installed in the vehicle. Eventually the packs will be built inside Factory Zero.
You can see that the pack is loaded onto a table, which then slides under the vehicle’s frame as it lifts a bit. Once lined up, it goes up and gets plugged into the Hummer. Then, little arms flip up under the vehicle to drive the main mounting bolts, securing the pack to the vehicle.
Dynamic Vehicle Testing
At the end of the assembly line, vehicles don’t just go out, get loaded onto a truck, and end up in a customer’s driveway. Plant personnel make sure it works like it’s supposed to before it goes out the door.
One rolling test the vehicle gets is an alignment check. This is simpler than on an ICE vehicle. While this is going on, robots go in front of the vehicle to make sure the headlights are aimed correctly. The car’s infotainment system is also checked.
Next, the vehicle goes through a virtual test. A driver takes the vehicle onto a pair of dynamometers (aka “dynos”) to drive the car without actually going anywhere. This checks not only the vehicle’s electronics and motors to make sure everything looks right, but also gives the battery pack a good bit of use in the factory where problems can be addressed more easily than at a dealer. The braking system also gets a check.
What’s Coming Up For Factory ZERO?
Factory ZERO is going to see several more models come out of its doors. The Hummer SUV, another variant of the Hummer EV is coming soon. There will also be the Silverado EV and Sierra EV (both the same truck, but one for Chevy and one for GMC, just like with gas trucks). They’ll also be building the autonomous Cruise Origin for urban transportation.
While it was interesting to get a behind-the-scenes look at GM EV production and meet some of the people, the whole series has more to offer. Be sure to check it out on YouTube.
Featured image by GM.
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