I remember the first time I visited Munro & Associates; I was a 20 year-old intern in Chrysler Group, LLC’s (as it was then called) Advanced Concepts Engineering team, and my job was to study saddle-style gas tanks and different packaging setups for Power Transfer Units (Chrysler was considering an all-wheel drive variant of the RU platform that underpins the Pacifica). I recall attending classes that Munro was teaching FCA engineers, and I remember being reprimanded — a year after my internship, when I came on full time in a different group — when the Ford Explorer PTU that I’d checked out as an intern never made its way back to Munro. (I still have no clue what happened with that thing). Anyway, after my two-year stint leading cooling system design for the JL Wrangler, I joined the circus over at the famous German lighting company, and started writing about cars. “Man, readers have no idea how much cool shit happens in the auto industry” was one of my first thoughts while working my new job. Among the cool things I wanted readers to see was benchmarking, specifically Munro’s benchmarking and costing analyses. In the summer of 2016, I’d run into Kevin, one of the many enginerds at Munro, while off-roading in the woods of northern Michigan, and we’d exchanged info so I could swing by Munro for a story. So in the fall of 2016, I stopped by to see what I’d remembered from my engineering days: thousands of parts just hanging on huge white pegboards, tables covered in suspension control arms and electronics and powertrain bits, detailed diagrams with dimensions and manufacturing processes spelled out — Munro was an engineer’s paradise, so I wasn’t surprised when my story on the company enraptured so many readers. Munro does cool stuff. I don’t know why I’m writing any of this; possibly because Munro’s president, Cory Steuben, talks a bit about our history at the end of this Rivian R1T teardown intro video (thanks for the shoutout!), which I will now briefly summarize:
Right away, Cory and Sandy show off something cool: That front trim piece ahead of the frunk is actually held on by magnets!
This is bizarre, as almost every other company uses plastic clips to hold on plastic trim/closeout panels. In fact, just the other week I was talking about how Ford was using two-piece clips to affix the F-150 Lightning’s plastic trim that surrounds the frunk. I even mentioned my distaste for the fastener choice, since it was so easy to drop a clip into the dark abyss between the frunk and the inner fender/firewall (Sorry Ford, that clip is gone):
Sandy and Cory note that Rivian’s strategy here is novel, but a bit expensive — not just because magnets cost more than little plastic clips, but also because the magnets require ferrous provisions on the front end module. And not just on the main upper cross-car member, but also on the headlights; this, Cory notes, just adds complexity to the manufacturing process:
“I’d use 3M Dual Lock,” chirps Sandy. This is essentially a velcro-style setup, and I totally see why Munro & Associates’ boss would suggest that. So long as there are locating features in the trim piece to make sure it sits exactly where it should (and that’s one of the advantages of the magnet setup, I assume — the piece will want to center itself), that velcro-style tape should work well. And it’s cheap. I’m not entirely sure why some regular ol’ Christmas Tree fasteners and some holes wouldn’t do the job, here; maybe it’s an aesthetics thing since this is a class-A surface?
Cory mentions that the two little plastic boxes (which hold electronics for the light and the federally-mandated frunk release switch) hot-staked to the enormous injection-mold that makes up the frunk could be the same piece instead of two different shapes. This, he notes, could save Rivian some cash.
I’m glad Cory mentioned hot-staking, because I was looking for that term recently when trying to remove the fabric part of my a 1994 Jeep Grand Cherokee ZJ’s door trim. This bit:
Unfortunately, flipping the panel over revealed that the fabric bit won’t come off, as it’s been heat-staked. It’s actually quite an elegant way to join two pieces:
Heat-staking is basically like plastic welding in that it involves mating two pieces (with at least one of them being plastic) by heating up and pressurizing one of the plastic parts to create a joint that requires no additional parts, won’t rattle or squeak, and features a nice, clean look. This diagram from British manufacturing company Goudsmit shows how it works:
Here’s the process in video form:
Anyway, by using the same little plastic boxes heat-staked to the tub, Rivian may be able to save a few pennies, as reducing the number of unique parts reduces overall vehicle complexity and cost. It’s one of the many things that Munro frequently points out as a key cost-reduction measure, along with things like using the right materials in the right locations, using the right manufacturing processes to build certain parts, reducing steps needed to build a component or system (often by reducing the total number of parts used), reducing fastener count/using cheaper fasteners when possible, and so on.
Removing the frunk reveals some nice hardware: chillers and inverters and motor mounts and ABS pumps, and all sorts of coolant and refrigerant lines. Plus, you can see vents in the wheel liners to help facilitate airflow through the front heat exchangers (it reduces pressure aft of the heat exchangers, facilitating flow) — like Sandy points out, the way these parts are laid out just looks good. And yeah, the typical owner is never going to see these bits, but how something is presented under the skin can also play into “perceived quality,” so it all matters. Plus, as Cory points out, many of the coolant lines are short, and they’re made of nylon (lightweight compared to rubber) with quick disconnects, which are easier to assemble and, if I had to guess, less likely to spring leaks than constant-tension springs (which the Rivian has a few of, Cory points out).
Cory also points out that Rivian uses a traditional air-to-refrigerant condenser out front rather than a liquid-cooled condenser (which basically just uses a radiator out front to cool liquid coolant, which flows into a liquid-cooled condenser that looks like the chiller pointed out above). As Cory says, a liquid-cooled condenser would allow the entire refrigerant system to be tightly-packaged; Rivian’s approach requires long lines and hoses to the front of the vehicle. I’m curious to know why Rivian made this choice; I used to work directly with the head of Rivian’s thermal team (a sharp dude) so I have no doubt there was some good thought put into the design.
Cory and Sandy also talk about the R1T’s body, pointing out the structure attached to the outside of the frame rails, which is there to make sure that the very outer 25 percent of the vehicle’s front end is tied in with its main structure; this helps the truck pass the Insurance Institute for Highway Safety’s rigorous Small Overlap Rigid Barrier (SORB) crash test.
Cory also notes the main upper rail (the “shotgun”) — a part that’s normally tied in with a vehicle’s body and that’s normally hydroformed (see video above; it basically uses hydraulic working fluid to press metal into the desired shape) — is made of a different material than the aluminum body (it’s steel) and is not hydroformed (It almost looks stamped and welded? — see image after the one below). I showed a shotgun rail in my Ford F-150 Lightning review as a way to demonstrate just how much body structure the Lightning shares in common with its gasoline counterpart. Have a look:
Check out that review to see more images of those F-150 Lightning rails; they’re nice and smooth — quite a contrast to the Rivian’s shotgun rails, which feature lots of welds:
Cory and Sandy also note that Rivian uses multiple brackets/jumpers to tie the outer fender to the shotgun rail. Sandy says he reckon’s there’s opportunity for parts reduction, here. Plus, you see those round indentations in the outer fender that tie it to the narrow bracket? Those are Tog-L-Loc Clinchings, three-step processes that clamp, draw, and lock two pieces of metal together without using fasteners or welds. In the video, the engineering duo gets into into lots more detail, talking about how the Rivian uses unique fasteners (a big no-no, when it’s avoidable), Cory shows a headlight access lid that seems entirely unnecessary/costly, there’s also an overly-expensive cast aluminum bracket holding the front end module to the shotgun rail — it’s all great stuff, so watch the video and get nerdy. I’m pumped to see more as the team at Munro & Associates continues to tear into Rivian’s impressive pickup. Wait a minute, isn’t this thing mostly aluminum. Hopefully, there’ll be some type of corrosion with these Rivians so in 25 years time you can wallow in it. Can’t wait to read all about your take on that.
- The COCKMUCHER who decided to put a PHILLIPS SCREW INTO A BRAKE DISC TO KEEP ME FROM BANGING A 10LB SLEDGE TO KNOCK THE BASTARD OFF!!
- The GEESE FUCKING, GOAT RAPIST.. who goes into WALMART and anywhere else that Hot Wheels exist.. and buys them all! SO when in go in there on my 8th birthday (2 days ago).. I CANT FIND A GOD DAMN THING!!!! THEN I GO ONTO EBAY.. AND FIND THE MOTHERFUCKING GOAT RAPIST SELLING THE FUCKING HOT WHEELS FOR 4BUX PER.. WITH 19.50 FOR SHIPPING.. FROM SHABOYGEN!!!!! Riveting stuff! A couple years back, I had to replace my laptop’s keyboard. This is one of the most common laptop repairs and should therefore be simple, right? Nope! To start, you have to take the entire thing apart. The keyboard comes out the bottom, and the entire rest of the computer’s internals are in the way. So I take the dumb thing apart and finally reach the keyboard. It’s held in by three screws. I unscrew them. It does not budge, because THE BLASTED THING IS HEAT-STAKED TO THE COMPUTER’S BODY IN 30 PLACES. So what should be a simple repair turns into a gross, plasticky nightmare as I drill out all the heat stakes and attempt to secure the new keyboard without their use. tl;dr heat stakes bad. God it it Festivus already? Bring on the feats of strength! The thing is, if there’s one thing about Velcro it’s that the more you use it the weaker it gets. In my case, about a week into my second set of soles I was measuring a 9:12 roof when with zero warning the soles of my shoes went “RI-I-I-P” and just peeled right off my boots! I slid six fucking feet—to this day the worst close call I’ve had—and was lucky not to go over the fucking drip edge. I returned those (used, beat-up) boots with extreme prejudice, and left an absolutely livid review. I’m not even the only person I know with this kind of story about Cougar Paws. Anyway, my message is this: if it’s important and it has a designed service life of more than about six months, don’t use Velcro. Even the most heavy-duty stuff will turn to shit on you at the worst moment. Hell, the floor mats on my Miata are held down by Dual Lock, and while it works better than the 25-year-old tiny plastic spikes that used to be under there, when I recently tried to remove the floor mats for cleaning it started to just peel away. That stuff has its place, but it’s not in anything important or factory-built. And yes, the Velcro has issues over time. But when you order new frunk trim, Porsche helpfully includes both sides of the Velcro with fresh adhesive. But they do not provide the apparently mythical solvent required to clean up the old gunk. Anyway, if the 3M tape has issues, it’s either poor surface preparation or the wrong tape. I build long lifed (Ie as long as I’m alive it will be fine) structures with the stuff. They can buy a report of the teardown and they can often “rent” parts that have been torn out of cars. This saves them the cost of having to tear the car down themselves – especially if they’re just after one part for benchmarking. Ford: I’d like one Dodge Dart please! Dodge: LOL, no. *FD: I work at an OEM. The teardown group was between us and the coffee machine in the BeforeTimes. We frequently got to see what they were working on as we ambled by. If we were either looking for a cost comp, or a supplier or a manufacturing process we would pay for a report or visit from Munro, (or their competitors, etc.) A lot of the times for the projects with the budgets we would use the vehicle for whatever benchmarking was needed while it was put together then do a teardown ourselves. Then try to put it back together to check for DFM/DFS. Also, fuck heat staking Worked on a number of Tesla/Rivian/Other “startup” EV company programs – it was really a complete 180 vs dealing with the traditional automakers. I was in a sales role, but worked closely with engineers…these companies were always sooooo much leaner in terms of manpower. Companies like Rivian and Lucid impressed me for the most part, but it always surprised me to see these projects come to fruition. On the other hand, I spent time working with companies like Karma and Nikola…and was less impressed. Yes, he can often appreciate good engineering–even if it isn’t the cheapest–but Munroe is someone I see more well liked by beancounters than he is by engineers. “Yeah, sure, that would improve reliability/performance/decrease complexity, but it would add 5 cents to our manufacturing costs, so NO!! Here’s the component designed 30 years ago and made by the lowest bidder, which will fail right after warranty expires, that we’re gonna use” I’m sure its rusting somewhere on your property. Hydroforms are expensive and take a good bit of tweaking to nail the dimensionals on, but they also do not seem to do as well as people would have hoped with SORB. Sometimes they do, but other times they just…bend. Once you add in all the necessary gussets and reinforcements to make it work, you’d have spent half as much for a welded assembly that weighs less. https://automobile.fandom.com/wiki/Porsche_FLA Maybe not air temperature but you may have on surfaces given such surface temperatures are not unheard of in also sunny Arizona: “When you look at hot pavement or asphalt at two o’clock in the afternoon in direct sunlight, the temperature (of the surface) is usually somewhere around 170 to 180 degrees Fahrenheit.” https://www.azcentral.com/story/news/local/arizona-weather/2021/06/10/warning-high-temperatures-mean-hot-surfaces-can-burn-you-officials-say/7640947002/ Having visited both Texas and Arizona I have experienced how Hellishly hot both places can get. Not a fan of quick disconnects at all, sure they’re quicker but I’m willing to bet they leak far more often than spring clamps. Ford used these on my 2014 F-150 (and I assume many other cars) and at around 110k, likely due to heat cycles, vibration, and just age, one of them started to leak. (Very common problem) The fitting is a Y with two quick disconnects and one spring clamp and the O-ring kit is an off the shelf item (telling) with three O-rings (also telling considering the truck only needs two, it’s a common enough problem that they sell one kit with extra parts to cover multiple applications). And the icing on the cake in order to replace the O-rings on the Y, you need to disconnect the quick connect at the expansion tank (o-ring not included in kit), and so now that the Y is fixed, the expansion tank fitting leaks. I’ve replaced this O-ring as well now with what I thought was the same size, but surprise surprise, it still leaks. Know what type of system I’ve never experienced leaks with? Constant tension clamps.
