Rivian R1T Analyzed by Teardown Expert
A comprehensive teardown of Rivian’s pioneering electric pickup reveals praiseworthy build quality, innovative thinking…and some lapses in manufacturability.
Rivian’s R1T is in big demand by both the public and the industry. OEMs are still scrambling to acquire their own examples of the pioneering, innovative electric pickup for competitive analysis and testing, typically paying brokers hefty premiums over the retail price. The hot-ticket trucks are in short supply; Rivian has for a variety of reasons struggled to ramp up its Normal, Illinois, plant (capacitized for 150,000 units annually when it was owned by Mitsubishi). The facility, which also builds the R1S SUV and the new, battery-electric Amazon delivery van, only achieved its first full 10-hour-shift day of uninterrupted production in early June. Line rate improved greatly by July.
Vehicle design plays a significant role in assembly efficiency as well as in build quality and customer delight. So, how does the R1T stack up in its DfM (design for manufacturability)? And what compelling technologies lurk underneath the sheetmetal? For a look deep inside the truck, SAE Media recently visited Munro & Associates, a leading product teardown, analysis, costing and lean-design consulting firm based in Auburn Hills, Michigan.
Prior to the R1T’s launch, company founder Sandy Munro hunted down two R1Ts for sale and purchased both, one from Rivian and one via a broker. One of the trucks is the subject of a comprehensive nut-and-bolt teardown by Munro’s engineers, whose detailed observations and data go into a series of commercially available reports.
The second vehicle became Munro’s daily driver and a touchstone for the teardown activity. The truck has performed beyond his expectation, including in regular off-road exercises. “It’s hands-down superior to the hybrid [Jeep] Wrangler Rubicon and the Land Rovers that I’ve owned,” Munro asserted.
Meeting Munro in his facility’s Rivian teardown area, he noted that his business now is almost entirely dedicated to the scrutiny of EVs, their subsystems and components. “For the most part we’re finished with ICE-related work,” he said. “There is enormous industry-wide interest in EV technology and design,” he said, “and we aim to be the go-to.” He pointed to two Tesla teardowns nearing completion in another area of the facility and said Ford F-150 Lightning and Chevrolet Silverado EV projects are in queue.
‘A bear to assemble’
A typical vehicle teardown takes roughly three months to complete, and according to Susan Smith, a veteran industry engineer with extensive automotive metals, seating and manufacturing experience who serves as program manager on the Rivian project, Munro’s team was about three weeks into the R1T when SAE Media visited. “We typically deploy a team of 12 on each teardown,” she explained. Around us, groups of engineers and technicians wielding hand tools and micrometers were methodically dismantling the truck’s interior and cargo areas. Components and subsystems are measured and weighed, their material content and function are assessed, the parts are tagged, then organized on display boards for further analysis. Engineers on laptops at an adjacent table were busy calculating part cost and labor hours using Munro proprietary software.
Smith and Munro compared their initial observations about the Rivian with their assessment of the Tesla 3 early in its 2018 teardown. “The Model 3 had fit-and-finish issues galore, and issues inside the cabin. The Rivian has no fit-and-finish issues whatsoever,” Munro said. “It’s far superior to where Tesla was at the same stage of that company’s production, relatively speaking. Of course, Rivian’s overall [manufacturing] volumes currently are much lower.”
“What I’m seeing is a really well-made vehicle,” Smith commented. “Fit/finish is first-class. Paint is beautiful. However, my impression is the R1T is very difficult to build. The design and engineering do not lend themselves to manufacturability. It looks to be a bear to assemble.”
Looking into the teardown vehicle’s increasingly skeletal body structure, the experts highlighted the various areas in which Rivian has much to learn about DfM. They pointed to excessive sealant applications and evidence of a lot of hand finishing and manipulation of the sealants and adhesives. Smith noted places that could enable water intrusion. NVH countermeasures, particularly bake-on mastics, appear to be more extensive than those used in other EVs. “The designers clearly wanted to ensure a quiet cabin, so may have gone a bit overboard to hit their interior dB targets,” Smith said.
A troubled marriage
While the R1T displays commendably tight body-panel gaps and tolerance consistency in all areas visible to the customer, it’s a different story underneath. The assembly workers responsible for marrying the body and chassis modules at Normal have a needlessly tough job, one that could go much more smoothly with design changes, Munro and Smith concluded.
“There are places on this vehicle where subsystems are being married, such as in the body decking operation and in introducing the IP into the front structure, where the operators must literally squeeze in between the sections to connect up the harness wires during the marrying process,” Smith explained. “It looks possible to accomplish at a slow assembly-line rate.” However, she cautioned that Rivian’s ability to ramp up to its projected line speed at Normal (and at the recently announced second plant in Georgia) will be hampered by gaps that are excessively close in critical areas.
“They’ve got to get their tolerances to where the assembly workers will have freedom to assemble this vehicle fast and without error,” she noted. “On this current design, everything is too close. In the decking process they’re dealing with extremely small clearances. This unnecessarily complicates the assembly process.”
Added Munro: “Body marriage on the R1T appears to be really, really tough,” he said. “Besides rethinking some of the tolerances, I’d probably put electrical connectors in different places versus where they are now. As it stands, this is not a vehicle design that allows operators to get their jobs done in a hurry.” He suggested that with minimal modifications, his team could “take a significant amount of labor hours out of the vehicle.”
Other observations from the early phase of Munro’s R1T teardown: The design of the ‘gear tunnel’ closures unfortunately has a protruding corner — like a blunt spear — that can be a leg-bruiser when the doors are deployed. The truck has an overabundance of bracketry, the functions of which could be consolidated to save complexity, labor time, cost and weight, Munro reckons. Smith noted that in some areas of the Rivian’s body structure, the weldments are overly massive.
And in some locations on the structure, the Normal body shop is applying both spot welds and MIG welds. “Considerable redundancy,” Munro commented. “Overall, they need to get their body welding and sealing processes sorted out to eliminate this. They also need to get those processes up to speed in terms of ensuring water tightness.”
In an all-new vehicle that is clearly loaded with smart, customer-delight features, the Munro experts noted many subtle design and engineering elements that impressed. The R1T’s non-exotic materials mix features a plastic composite cargo bed, and cleverly employs double leaf springs to hold up the tambour door over the cargo space.
Smith is impressed by the cross-car beam supplied by Germany-based ElringKlinger, as well as the adjacent HVAC ducting that uses various plastic materials to address different loads and conditions. The cross-car beam is produced using hydroformed hybrid technology (HFH). The polymer-metal hybrid involves a mold tool combining two processes — hydroforming and plastic injection molding — in a single step. According to ElringKlinger, a robot places an extruded, thin-walled metal tube into the mold. After the two halves of the mold are closed, the interior of the tube is filled with cold water at 600 bar (8700 psi), which causes it to expand and assume the desired shape. The injection-molding process then begins in the same mold cavity.
Molten plastic is injected into the mold at 300 deg. C and then solidifies in the cavity between the mold and the reshaped tube, again at 600 bar. Internal counterpressure ensures the aluminum tube does not collapse during the injection process, the company maintains. Once the part has cooled and is dimensionally stable, the hybrid part is removed by a robot and transferred to downstream processing where various vehicle-specific plastic elements are added.
At the time of our visit, the teardown team was just beginning its scrutiny of the R1T’s battery pack, making that an article for another time. Initially, Munro is impressed with the pack design’s “bottom-up” cooling strategy featuring a cooling plate between each pair of cylindrical 2170 lithium cells. The traction motor design is “robust,” he said, with the Bosch electric machine using hairpin-type wiring.
Director of electrification Tom Prucha previously was with in-wheel-motor specialists Protean Electric, where he developed an acute assessment of EV driveline dynamics. He said he appreciates the Rivian’s propulsion system architecture with its four separate drive motors. “It’s best-in-class from a performance standpoint and demonstrates how an electric drive system can and should work,” Prucha noted. “Having said that, I’m sensitive to driveline backlash. When I tip in and out of the throttle in the Rivian, I can feel four separate backlashes, one from each motor. I think it’s inherent with four motors and four gearboxes.
“Could they tighten that up? Probably,” he said. “Would it affect vehicle efficiency? Possibly.
“For an all-new EV, the Rivian is an outstanding first effort,” Sandy Munro affirmed. “But overall, it needs to be ‘scrubbed’” — his term for a comprehensive culling of all extraneous parts and a rethink of key design areas that cause manufacturability issues.
“From what we’ve seen to date, I think Rivian could take a lot of money and many kilos of weight out of this truck — and make it a lot easier to build.”
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