Hey, I have to say that you guys (And the rest of Munro) present yourselves extremely well! You make me wish I was younger so I could come work with all of you. Keep the integrity high please! And oddly enough, I live in Lincoln, where Cory is originally from. Wish him and I would have run into one another when he still lived here. Tell him yeh from Lincoln!
HOORAY!! Finally a complete super review of how these covers work!!! THANKS!! We had to take apart (did it ourselves to get it done in a timely manner) our panel system to get a jammed panel out and be able to use the fully opened bed we needed. Thanks again!!!
Pretty crazy, looks like these are going to have 100% failure rate within a year or so. They could also fix this by having the main shaft center-driven by a secondary shaft that goes to the center. That way they can leave the motor on the side.
I had the same thought, two shafts. Couldn't they add tiny bearings/rollers where two surfaces slide against each other? Not sure that would solve the gear jumping problem, but should help longevity by almost eliminating friction.
@@DanielZajic Yeah fundamentally agree. Sliding frinction is killer here. But bigger modified rack teeth and bigger diameter of shaft to support torsional twist should suffice.
@@DanielZajic yeah didn't see a set of bearings on top pressing cover down onto gear. Maybe that is what that worn plastic piece was trying to do that they showed.
Also re the leaf springs, as you mentioned it looks like the single spring didn't give enough force, so they doubled them up. This was probably because they already had the parts ordered, when in reality the best option was probably a NEW leaf spring with ~50% greater force, instead of 2x+ that this double spring gives.
The second spring doesn't need to be full width, tapered from the sides would make the spring force variable as it compresses. You see this in firearms to produce equal cocking effort throughout hammer travel when using leaf springs.
Fascinating! One of the more unusual aspects, definitely worthy of a teardown to see how it works, as it's not a "usual" automotive part... would never have guessed they STACK inside for storage! (was wondering how/where they rolled up, like CyberTruck...) Thanks! Hope they can get it more reliable!
Public Storage locker door, on the diagonal. Shutter companies of all sorts make this stuff.... counter shutters for service counters and kiosks, for example.
Great video - thanks for this. I own this truck and love it except for this cover. You did miss one of the main problems with this design. Mine came with small pieces of gravel on top of the cover that got into the interlocking slat areas (I think the fine gravel came from how they shipped the truck to me on a bed with older cars above it). Once gravel gets into the slots between the slats, there is no way to get the gravel out and the slats do not sit flush with each other so they do not fit under the cover when you try and roll it up. A slat that is deformed up a little will hit the plastic cover over the containment area and stop the roll-up. They did not design this cover to survive small gravel on top of the slats. The cover you were showing is brand new - use it on a gravel road for a few days and it will fail. It was designed to be used in the city.
Awesome breakdown of this thing! I own an R1T and have been nursing my cover with lube and infrequent use. If Rivian will let me without voiding my warranty, I’d like to cut some of the bottom leaf spring out to reduce the force and machine some wider drive gears for more engagement. I could tell from day one with my truck that friction was the covers problem.
The Tonneau cover in the Rivian derives from a 1876 patent for the Rack and Pinion steering on the "Coventry Rotary" tricycle. That adult tricycle, one of which was later (1892) owned by Queen Victoria, was in the year 1882 converted into an electric tricycle by a Frenchman. It was the First Electric Car. I happily have an 1877 Coventry Rotary Trike... which is still ridable. It would be neat to find the detailed design of the French Conversion and repro it on the original Trike.
There are two air compressors on the truck. Replace the "leaf spring" with a regulated air spring. That way it could have a constant force applied to slat stack, regardless of position.
I was thinking of something similar like those high strength pressure balloons used to lift houses for foundation work or door jam separation (getting into your locked car). Anyway a custom version of that should fit pretty flat in the bottom when not inflated. Then just sync pressure in that to lead motor actuation on close and just release the valve and allow the stacking/motor to compress/deflate on open.
THANK YOU GUYS so much for this informative video. One corner of the last slat in my cover dislodged from the rest and after watching this video and fully understanding how the system works i was able to repair it myself!! You are doing important work!
But adding a second motor would mean you could halve the power of the existing motor - so 2x smaller motors and maybe use an existing window regulator motor and take advantage of the massive volume cost reduction.
Torsion is the rotational force difference between the ends of a driven object, and a function of mass momentum. The other terms describe the angular displacement difference between the ends.
@@psdaengr911 No, torsion is the angular displacement difference between the ends, resulting from the application of torque, which is the problem. There isn't a rotational force difference between the ends of a driven shaft, but there is angular displacement as a result of the applied torque... which is torsion.
I have to observe that the Tesla solution seems to look a lot more simple, inexpensive, perhaps rain resistant, and reliable than this Rivian one, which reminds me of the kind of solution that Rube Goldberg might have come up with. Getting the plates to interlock properly every time, in an environment with rain, ice, snow, sand, and falling tree debris seems more like a great hope than a design result.
Those roller shutters are certainly a tried-and-tested design. It's just a matter of 30-40% more space. Everyone would lose some gear tunnel space, whether they had the cover or not. This thing can probably be made to work with a bit more experience, although I agree the 'bits getting in the joint' problem could prove insurmounable.
That is a totally dysfunctional design. As soon as I saw the interlock I thought how could that design get out the door. Just the least bit of dirt, leaf or twig will break the weather seal and prevent the parts from engaging. The extreme aspect ratio of the slats will cause them to bind with the slightest imbalance in bedwise movement. All that is in addition to the problems discussed in the video. Rivian has a major problem on their hands and makes one wonder what other poor design choices are waiting to be discovered.
I've had my truck for some time before having an issue. This was super helpful in how it works. The service center fixed in in the open position. I hope they come up with a fix soon as I really like the feature.
🤗 SORRY ERIC,I DID NOT GET THE MEMO…FOR FLANNEL FRIDAY 😊 THANKS FOR YOUR WORK AND THANK KEVIN AND SCOTT FOR KEEPING YOU ON YOUR TOES 😁 THANK THE WHOLE MUNRO TEAM FOR THEIR SUPPORT 👍🤗😎💚💚💚
A simple way to negate any potential twisting of the synchronizing shaft between the two side gears would have been to put the motor and the reduction gear set in the middle of vehicle. The shaft would be powered at the mid point, and BOTH ends of the shaft would twist equally and in the same direction under load. No complicated synchronized stepper motors necessary. If there isn’t enough packaging space for the motor to be mounted in the middle, the motor shaft could be extended and only the reduction gears would need to be centered on the cover. It doesn’t matter how much total backlash is in the gear set or how much the shaft twist under a torque load. The ONLY thing that matters is that both end gears that engage the rack remain synchronized. The simplest way is to account for the twist and make sure it is balanced between the left and right sides.
Thanks Scott and Kevin for your discussion of the of the tonneau cover issues. During Ice and snow storms this cover would be inoperable. The plastic on the end of the slats will be worn out quickly by the little gears. Its always interesting to watch as Munros solutions unfold.
I think the problem is torsion on that drive shaft. They should drive the shaft directly from the motor, and have reduction gears at both ends of the shaft. So the shaft would spin faster, with less torque, and therefore less torsion. And the smaller angular misalignment between the ends of the shaft would be divided by the gear ratio to make an even small angular misalignment between the drive gears.
Just an idea: keep the center rod, and add a second motor like Sandy suggests. Increased cost and complexity, yes, but if you're going to add a second motor, the increase in complexity from trying to synchronize the motors could be solved by keeping the rod in place.
This is the sort of mechanism I might have designed when I was a lot younger and suffered some hard lessons as a result. It's poorly conceived for being little more than a roll-up door as you'd find on a garage or window shuttering, stuff that's been around for decades, but notably those examples are assisted by gravity. The sections should not come apart and probably would be better driven using a returned pull cable or chain on each side attached at each end so that the tonneau links are always in tension, much like a pool covering. I think the connecting shaft torsional stiffness or lack of may have been an unnecessary diversion as we were not privy to a demonstration of its operation, smooth or otherwise. The rack and pinion idea is doomed because the friction of the reaction surface (opposite side of the rack) would be excessive with tooth profile used, not helped by dirt and lack of lubrication. Certainly a non-involute tooth profile may help reduce radial reaction force but I think in general that is simply rearranging the deck chairs on the Titanic. As for the spring compensation - as a guess I expect that the reason for the twin leafs each side is to achieve a suitable fatigue lifetime. Frankly, it looks like an afterthought anyway. But thanks for video guys, love this stuff and it's nice to see some constructive comments from other viewers.
@5:38 it doesn't just want to "almost twist"... it does twist (deflect in torsion). Before that gear backlash was mentioned, and that's true, but the backlash doesn't matter to synchronization of left and right sides because there are no gear transfers between them.
I can explain the expression "tonneau cover": to answer that we need to go back to the early days of cars and the dawn on automobile racing. In the early 20th century, car manufacturers began offering options and configurations for their models, (remember that people used to buy a chassis and engine, and then go to a body shop to finish the car) and one popular option was the ‘tonneau.’ Initially, the term was used to designate an open, rear passenger compartment - typically rounded like a barrel. These tonneaus often included soft leather coverings to protect the compartment when not in use. The term tonneau cover would later be adopted by racers during the early Bonneville Salt Flat days when hotrodders would cover up open areas of their vehicles to reduce wind drag.
You could add a drive gear to the center of that rod and add a second rod with a gear from the motor and drive the main rod from it's center. Then any twist in the main rod would be equal at both ends assuming friction on both ends is equal. This thing really looks like it will only be suitable for people who keep their truck in a clean garage. Here in the northwest fir needles combined with the rain in winter will be a huge problem for one of those left outside for any length of time. Maybe they should sell a Rivian branded tarp to throw over it.
Or keep the motor in the same location but have a parallel half shaft from the drive motor that engages the full shaft at the center, thereby, splitting the torque from the center, eliminating the twist. More parts but within the form factor.
@@jasonhunt007 Yeah but bigger diameter of shaft should be enough to limit torsional twist. Also adding bigger teeth should eliminate any extra protrusions into already small truck bed without moving motor into the middle.
You had mentioned a solution being dual synchronized motors. I think that would address a lot of the problems. As well as removing the requirement for the shaft entirely. That idea has my vote. Are we taking votes?😂
Bigger shaft its much much cheaper, easier and not so hard to design it right. Clearly those doors were after thought for Rivian. Afterall they are new compay.
I’d add a PTFE strip to each track on either side to reduce friction and wear, also maybe the better tooth engagement, I would also look at maybe a different spring arrangement, possibly the plates on hydraulic struts like a hood/bonnet.
no space for struts. Leaf spring is compact solution. They just need make better surface interfacing as u mentioned already. Or just give up and make totally different cover system. Strong fabric roller mechanism would already suffice for its role.
Add another gear wheel on both sides to drive the slides and increase the diameter og then rod would help. Furthermore redesign the spring so the pressure plate does not need to slide and maybe add a pulley that pull the spring down when the rod rotate to retract.
Looking at the roll up and storage mechanism for the bed cover.........makes me wonder what the actual mean time to failure will be as well as the overall failure rate. Seems like it's too complicated to survive in the wild.
The variability of the distance between the side rails could cause pinching. Which could bind the slates and cause the gear teeth slip that you mentioned. I like the idea of greater engagement to prevent slip but can see how that may have been designed in as a clutch or fail safe point.
Another option would be to allow the driven-side gear to have some spring-regulated slack up to one tooth total travel. This would allow the driven side to delay and compensate for the bar twist dynamically. The rod would be driven by a gear, then a spring-loaded gear would be adjacent to it to drive the near-side action and the rod would transfer the torque to the far side. The cover rigidity would reinforce the spring stiffness so would push and relieve the built-up spring tension to dynamically compensate for the rod-twist. This fix would be cheap to implement with minimal other changes. Changing the gear profile for a deeper bite on top of this would be a very welcomed change, for sure... Putting the motor in the middle would give nominally equal twist, however there would be minimal dynamic compensation for differential friction from the tracks... but the motor in the middle and then both track gears being spring-loaded on top of the profile changes would provide a very effective fix.
For a smaller diameter circular design, Rivian may test using a quite fine stainless steel “linked” mesh, a.k.a Milanese style steel mesh. Then having the mesh molded with silicon rubber with the suitable properties = heat and cold-resistant, UV-resistant, low aging, etc.
It seems like a fair challenge to balance the retraction performance where you want a light spring tension with the extension performance, where you need strong spring tension. They also get binding when the slats thermally deform and try to retract into the tight entrance to the cartridge. Seems like a second motor would give you added torque to overcome the spring tension but wouldn't necessarily improve binding or synchronization. I'm surprised Rivian hasn't yet rolled out the manual cover.
I wonder if it's possible to adjust the spring tension between extnesion and retraction (maybe with a driven cam). Hard to fit in such a mechanism I suspect (and make it reliably shift under max tension when fully retracted).
I think either adding a thicker cross link with a lower torque bias, or adding a mirrored second regulator in parallel would solve the misalignment. Secondly, adding roller tracks, with rollers on each slat staggered in a zig-zag pattern to allow stacking, could solve the wear problems
A motor at each side alongside having the side to side connecting bar still in place is the way to go with a fail safe so if one motor stops working they both stop til repaited. either that or somehow mount the motor bang in the middle so the push/pull force is even at both sides
Looks like when Rivian was trying to follow the Land Rover legacy (target market, design elements, off road + on road capabilities), they also ended up copying some reliability issues. The problem with this cover is that it was clearly not tested and even if they improve it, it’s going to be a nightmare for owners. Dust and tiny rock is going to get into the mechanism and with 90%+ utilization it will break. In a year, two years, or four years but it will break for sure. Guaranteed. Hope some aftermarket companies are already realizing it and will come up with replacements that would ensure replacing this won’t be crazy expensive.
Garbage is also a french derivative word that I believe nicely sums up the Rivian Tonneau. I think it will soon be on the guillotine metaphorically speaking ... The biggest challenge for Engineers "just because you can, doesn't mean you should".
Great presentation combo!! Really enjoying the Rivian content, the Plaid/Model Y (both) breakdowns were also awesome!! I'd love to see a Lucid breakdown especially since their CEO keeps dropping knowledge on their channels Tech Talks... Thanks Munro Live!!!
Maybe run the drive shaft (after the final gear reduction) to the centre of the bed. Then run two hollow half shaft back the the pinion gears at either side (one would have the drive shaft inside it) so that they have equal wind up under the applied torque.
About the wear and tear caused from the big leaf spring, I would have use a lifting mechanism, using articulated arms like a front windshield wiper system.
The leaf springs compress to practically nothing. Any articulated system would need rigid components which therefore have thickness plus possibly extra thickness at any hinges. There is only enough space for the slats.
Tighten the tolerance like mentioned in the video so there are deeper slots and longer teeth on the gears. Have a rod coming off the transitional gear and have a solo drive gear that mounts to the center of the current drive rod. Would be in the center, so in theory the flex going to the drive lines would be equal. No need for a second motor, so a lower increase in cost. Might even be a solution that could shorten any recall/ warranty labor.
Second motor: bad idea, too complex to keep DC motors in sync. A hollow aluminum shaft would give you the modulus of stiffness to eliminate torsion wind-up. I agree with designing the the drive gears with deeper teeth. A higher grade plastic for the notched track such as Delrin (polyoxymethylene) could reduce wear, though Delrin is fairly expensive. I believe this issue is fixable without having to change the packaging space or assembly procedure, though it will be more expensive to manufacture due to material cost
I like the tank track sprocket idea. Coupled with a larger diameter drive tube to reduce winding while minimizing weight, along with a low force stacking mechanism the alignment issue should be manageable. For stacking I envision simple geared lifting arms on each side of the magazine, connected to the gear trains, that are timed to lower one slat thickness as each slat arrives in the magazine. The arms may require gentle springs on their top surfaces to allow positive engagement/disengagement of the slats, but wouldn't need to provide anything near the full lifting force the existing springs must produce.
This is interesting idea! Def adding complexity but would reduce wear. Essentially have the spring be pushed down a little at a time by a motor until the tunnel is fully inside and then tension is put to keep the panels from rattling....Coool idea!
Rivian has sent out emails to preorder holders stating in part: "We recently shared with R1T owners that we are upgrading the powered tonneau cover. As we go through the process, we are removing the powered tonneau cover from production. We plan to re-introduce this feature later, but a date has not been set. For the foreseeable future, all R1Ts will come with either a manual tonneau cover or no tonneau cover. Since you have selected a powered tonneau cover, your configuration will need to be updated to either a manual tonneau cover or no tonneau cover. It’s important to note this choice will not impact your delivery timing estimate coming later this month."
Already happening. That's why they made it an option instead of standard. Hoping less people buy it. Less issues to deal with. Those that do buy it pay $1500 so they cover that cost it seems.
@@BFArch0n Rivian has only delivered R1Ts with this option equipped so they are still being installed with this revision on every truck delivered. If you order without the powered tonneau, you aren't getting a truck at the moment.
Instead of moving the motor to the middle or adding a second motor, just run a rod from the side motor to the middle where it gears into the full length rod.
Why not drive the shaft from the center? Less expensive than a second motor, synchronization solved. And the second tonneau spring doesn't need to be full width. Taper the sides of the second spring to make the spring force variable as it compresses. This is done in older firearms to produce equal cocking effort throughout hammer travel when using leaf springs.
They could wrap a tonneau cover around the gear tunnel, the style would be more like the cybertruck's tonneau with connected sections. The gear tunnel would be lined with plastic with drains in the wheel wells. The gear tunnel would be a tube with an outer rail to guide the tonneau cover in. The length of the gear tunnel works to completely store the tonneau cover.
Scott, let Kevin speak! Also, I’m wondering if the RCA would point to skipping gears because of the high spring pressure requiring the system to do a lot of work. The spring steel was probably sized for a static system. I bet they had to double the spring steel to keep the collapsed from bouncing around while the car was on the road, going over bumps.
Leave the motor where it is, but add another shaft right next to the existing one, and put two little mating gears at the middle of each shaft. The motor now only drives the new shaft, and the new shaft drives the old shaft *from the middle* via those two little gears - now you should have the same twist at each end where the old shaft drives the slats.
You beat me to it 🙂They should treat the main shaft as a torsion bar, and if driven from the middle, it should result in almost identical and synchronous torque on both ends. This will greatly reduce the discrepancy on both ends.
@@kschleic9053 ... and I doubt they do. The downside of space optimization on generation 1. They've left themselves with no option to retrofit a new solution for the current design. I see them having to design a fix that intrudes into the gear tunnel that means they ALSO have to redesign their $5k camp kitchen. 😬
I appreciate all the consideration on how parts are manufactured, like the powdered metal gearing. Any idea what plastics they used? Maybe show how a force gauge could show the spring rate?
Great review and assessment team Munro! Thank you. Being a new auto company, re-engineering everything from the ground up is no easy task. Tesla from the start focused on simplicity and part reduction, where Rivian’s initial approach was the opposite.
I would have designed the slats smaller and used a roller-style spool. Plus, I would have routed the cover down before spooling, which means the spool would be smaller. I would avoid two motors because of the potential synchronization issues. Instead, they could use a bigger cross shaft to minimize angular deflection between the driven gear and follower gear. Another option is to run a shaft from the motor to the center of the vehicle in order to spin the cross-shaft from the middle as opposed to from the end.
THANK YOU!!! I've been wanting to see this. I'm stuck with my bed nearly covered completely. I need to get the slats back into the storage container so I can at least use my truck bed. But this is the only think I'm not happy with. Otherwise my R1T has been perfect.
Helical racks would have to be even shallower though and require even tighter tolerances. They would also have problems with the interfaces from one panel to the next. A straight cut gear has the advantage that the gap between panels just becomes another tooth.
Nice show down of the mechanism and how and where it fails. I just wondered, could they introduce a secondary drive and keep this connecting rod to just transfer the rotation without the load. So the rod will stay connected but on the secondary side there will be no mechanical connection but instead there could be a rotary encoder which will control the secondary drive. This way you will have no twisting of this rod and also no fancy controlling to sync the two drives. But on the other hand I habe no idea if this dependance of such a secondary drive would be a smart design choice.
Some what unusual that the axle rod wasn't driven from the center as noted - would keep the motor mass central too. At a guess, Igus could have supplied many parts off the shelf that have been tooled up also.
Great video, one questions I would have could you add a half shaft with a geared to the main shaft at the center? So the one motor would still be used and note moved to the center but the half shaft would move the movement of the gear to the center of the main shaft equalizing the torque on the main shaft.
I'd recommend canted worm gears and Teflon coat the slat slots to take up the friction. Most of the other parts could be carried over as the worm gear would minimize twist lash due to reduced ratio. The system would never misaligned, force of push on the slats would be increased likely 2X and again alignment would be far less an issue.
Hey, I have to say that you guys (And the rest of Munro) present yourselves extremely well! You make me wish I was younger so I could come work with all of you. Keep the integrity high please!
And oddly enough, I live in Lincoln, where Cory is originally from. Wish him and I would have run into one another when he still lived here. Tell him yeh from Lincoln!
What’s up Garn! This is Cory. I grew up living by Mahoney Park by 70th street, and I went to Pius X high school. Small world!
HOORAY!! Finally a complete super review of how these covers work!!! THANKS!! We had to take apart (did it ourselves to get it done in a timely manner) our panel system to get a jammed panel out and be able to use the fully opened bed we needed. Thanks again!!!
You're welcome!!
Mine was broken at delivery so they just disabled it in the open position.
Great explanation and demonstration. And The video quality of all Munro Live has increased so dramatically over time!
Thanks Pete
Pretty crazy, looks like these are going to have 100% failure rate within a year or so. They could also fix this by having the main shaft center-driven by a secondary shaft that goes to the center. That way they can leave the motor on the side.
May not be a total fix. basic problem is friction, a fluoropolymer guide may be required.
@@unreliablenarrator6649 yeah definitely need some materials changes too
I had the same thought, two shafts.
Couldn't they add tiny bearings/rollers where two surfaces slide against each other? Not sure that would solve the gear jumping problem, but should help longevity by almost eliminating friction.
@@DanielZajic Yeah fundamentally agree. Sliding frinction is killer here. But bigger modified rack teeth and bigger diameter of shaft to support torsional twist should suffice.
@@DanielZajic yeah didn't see a set of bearings on top pressing cover down onto gear. Maybe that is what that worn plastic piece was trying to do that they showed.
Also re the leaf springs, as you mentioned it looks like the single spring didn't give enough force, so they doubled them up. This was probably because they already had the parts ordered, when in reality the best option was probably a NEW leaf spring with ~50% greater force, instead of 2x+ that this double spring gives.
Maybe instead of doubling, they could put one in the middle for a total of three.
@@Kulric or cut 2nd element into half
@@alesksander yeah provide more tension later in stack where you need it more.
The second spring doesn't need to be full width, tapered from the sides would make the spring force variable as it compresses. You see this in firearms to produce equal cocking effort throughout hammer travel when using leaf springs.
@@rgeraldalexander4278 Yeah that's beauty of leaf springs. They are quite adaptable and fine tuneable for cheap and quite easily.
I appreciate you Scott and Kevin, it was educational.
Fascinating! One of the more unusual aspects, definitely worthy of a teardown to see how it works, as it's not a "usual" automotive part... would never have guessed they STACK inside for storage! (was wondering how/where they rolled up, like CyberTruck...) Thanks! Hope they can get it more reliable!
Public Storage locker door, on the diagonal. Shutter companies of all sorts make this stuff.... counter shutters for service counters and kiosks, for example.
@@citylockapolytechnikeyllcc7936 I've seen lots of roll-up doors in those situations, but never an automatically stacking system.
Great video - thanks for this. I own this truck and love it except for this cover. You did miss one of the main problems with this design. Mine came with small pieces of gravel on top of the cover that got into the interlocking slat areas (I think the fine gravel came from how they shipped the truck to me on a bed with older cars above it). Once gravel gets into the slots between the slats, there is no way to get the gravel out and the slats do not sit flush with each other so they do not fit under the cover when you try and roll it up. A slat that is deformed up a little will hit the plastic cover over the containment area and stop the roll-up. They did not design this cover to survive small gravel on top of the slats. The cover you were showing is brand new - use it on a gravel road for a few days and it will fail. It was designed to be used in the city.
This post by Jeff Trom was all that needed to be said about the Rivian tonneau cover.
As soon as I saw their interlock design this is exactly the outcome I expected. It should never have been considered let alone produced.
The problem is it was designed but never tested
Appreciated the compare/contrast with Tesla’s approach! 👍 Looks like Junior is still in school… Great job, Scott and Kevin!
Thanks! 👍
Awesome breakdown of this thing! I own an R1T and have been nursing my cover with lube and infrequent use. If Rivian will let me without voiding my warranty, I’d like to cut some of the bottom leaf spring out to reduce the force and machine some wider drive gears for more engagement. I could tell from day one with my truck that friction was the covers problem.
The Tonneau cover in the Rivian derives from a 1876 patent for the Rack and Pinion steering on the "Coventry Rotary" tricycle. That adult tricycle, one of which was later (1892) owned by Queen Victoria, was in the year 1882 converted into an electric tricycle by a Frenchman. It was the First Electric Car. I happily have an 1877 Coventry Rotary Trike... which is still ridable. It would be neat to find the detailed design of the French Conversion
and repro it on the original Trike.
Definitely must be getting cooler in the midwest when the flannel and vests come out!
You got that right!
There are two air compressors on the truck. Replace the "leaf spring" with a regulated air spring. That way it could have a constant force applied to slat stack, regardless of position.
I was thinking of something similar like those high strength pressure balloons used to lift houses for foundation work or door jam separation (getting into your locked car). Anyway a custom version of that should fit pretty flat in the bottom when not inflated. Then just sync pressure in that to lead motor actuation on close and just release the valve and allow the stacking/motor to compress/deflate on open.
Could also potentially use air to puff debris out of teeth connecting slates
Took delivery of my R1T in Nov 22 and I'm finally scheduled to bring it in for the tonneau cover repair next week... unfreakingbelievable!
Flannel Friday!
Another Munro and ASSociates exclusive...they should really do Miniskirt Mondays...fits them better 😂
Thanks!
Thank you!
THANK YOU GUYS so much for this informative video. One corner of the last slat in my cover dislodged from the rest and after watching this video and fully understanding how the system works i was able to repair it myself!! You are doing important work!
Great episode, super clear delivery, thanks so much for your positivity too!
Thanks Neill
Nicely done. Great way to explain the engineering challenges
But adding a second motor would mean you could halve the power of the existing motor - so 2x smaller motors and maybe use an existing window regulator motor and take advantage of the massive volume cost reduction.
Torsion is the word you are looking for instead of twist, wind up, or torque bias @ 5:30
Torsion is the rotational force difference between the ends of a driven object, and a function of mass momentum. The other terms describe the angular displacement difference between the ends.
@@psdaengr911 No, torsion is the angular displacement difference between the ends, resulting from the application of torque, which is the problem. There isn't a rotational force difference between the ends of a driven shaft, but there is angular displacement as a result of the applied torque... which is torsion.
I have to observe that the Tesla solution seems to look a lot more simple, inexpensive, perhaps rain resistant, and reliable than this Rivian one, which reminds me of the kind of solution that Rube Goldberg might have come up with. Getting the plates to interlock properly every time, in an environment with rain, ice, snow, sand, and falling tree debris seems more like a great hope than a design result.
Those roller shutters are certainly a tried-and-tested design. It's just a matter of 30-40% more space. Everyone would lose some gear tunnel space, whether they had the cover or not. This thing can probably be made to work with a bit more experience, although I agree the 'bits getting in the joint' problem could prove insurmounable.
And at some point that multiple gasket design will fail as well!
That is a totally dysfunctional design. As soon as I saw the interlock I thought how could that design get out the door. Just the least bit of dirt, leaf or twig will break the weather seal and prevent the parts from engaging. The extreme aspect ratio of the slats will cause them to bind with the slightest imbalance in bedwise movement. All that is in addition to the problems discussed in the video. Rivian has a major problem on their hands and makes one wonder what other poor design choices are waiting to be discovered.
@@PeteLenz Right after the first time it is parked under a dirty tree!
I've had my truck for some time before having an issue. This was super helpful in how it works. The service center fixed in in the open position. I hope they come up with a fix soon as I really like the feature.
🤗 SORRY ERIC,I DID NOT GET THE MEMO…FOR FLANNEL FRIDAY 😊
THANKS FOR YOUR WORK AND THANK KEVIN AND SCOTT FOR KEEPING YOU ON YOUR TOES 😁
THANK THE WHOLE MUNRO TEAM FOR THEIR SUPPORT 👍🤗😎💚💚💚
A simple way to negate any potential twisting of the synchronizing shaft between the two side gears would have been to put the motor and the reduction gear set in the middle of vehicle. The shaft would be powered at the mid point, and BOTH ends of the shaft would twist equally and in the same direction under load. No complicated synchronized stepper motors necessary. If there isn’t enough packaging space for the motor to be mounted in the middle, the motor shaft could be extended and only the reduction gears would need to be centered on the cover. It doesn’t matter how much total backlash is in the gear set or how much the shaft twist under a torque load. The ONLY thing that matters is that both end gears that engage the rack remain synchronized. The simplest way is to account for the twist and make sure it is balanced between the left and right sides.
Scott and Kevin are really good. Great video
Thanks
Superb communication skills!
Constructive and deconstructive commentary from you both!
I give you an A+____
Been waiting for this one. Browsed a Rivian owner forum website awhile back. This seemed like the part most people were having problems with.
Well done description ... tough problem for Rivian to fix.
Thanks Scott and Kevin for your discussion of the of the tonneau cover issues. During Ice and snow storms this cover would be inoperable. The plastic on the end of the slats will be worn out quickly by the little gears. Its always interesting to watch as Munros solutions unfold.
I think the problem is torsion on that drive shaft. They should drive the shaft directly from the motor, and have reduction gears at both ends of the shaft. So the shaft would spin faster, with less torque, and therefore less torsion. And the smaller angular misalignment between the ends of the shaft would be divided by the gear ratio to make an even small angular misalignment between the drive gears.
If the primary issue is indeed the torsion on the drive shaft, then yes, this would be a terrific solution. 👍
Also use extruded hollow tubing to transfer rotation instead of a solid shaft.
Just an idea: keep the center rod, and add a second motor like Sandy suggests. Increased cost and complexity, yes, but if you're going to add a second motor, the increase in complexity from trying to synchronize the motors could be solved by keeping the rod in place.
Yeah I think removing the shaft and bearings is an idea to reduce the cost and make the second motor more plausible.
It looks like part of the job of the rod is to hold rollers for the slats so a rod of some kind would still be needed. Might as well make it driven.
What not just add a second rod with a gear in the middle? It would not use as much space and even out the torque on both sides
Change the transfer rod to wider aluminum tubing and maybe put reducing gears on both sides.
Phenomenal review. Great suggestions for Rivian.
New intro is fire!
Thanks Peter
Thank you!
Another great analysis, thanks!
Sandy talked about eliminating fasteners.... don't buy a Rivian, saves materials, energy and money! I deserve an award!
Good job, very informative and interesting.
Glad you enjoyed it!
Been waiting for this video! Thanks guys! Here’s hoping they get it redesigned before I get my R1T.
I love the new intro
This is the sort of mechanism I might have designed when I was a lot younger and suffered some hard lessons as a result. It's poorly conceived for being little more than a roll-up door as you'd find on a garage or window shuttering, stuff that's been around for decades, but notably those examples are assisted by gravity. The sections should not come apart and probably would be better driven using a returned pull cable or chain on each side attached at each end so that the tonneau links are always in tension, much like a pool covering. I think the connecting shaft torsional stiffness or lack of may have been an unnecessary diversion as we were not privy to a demonstration of its operation, smooth or otherwise. The rack and pinion idea is doomed because the friction of the reaction surface (opposite side of the rack) would be excessive with tooth profile used, not helped by dirt and lack of lubrication. Certainly a non-involute tooth profile may help reduce radial reaction force but I think in general that is simply rearranging the deck chairs on the Titanic. As for the spring compensation - as a guess I expect that the reason for the twin leafs each side is to achieve a suitable fatigue lifetime. Frankly, it looks like an afterthought anyway. But thanks for video guys, love this stuff and it's nice to see some constructive comments from other viewers.
@5:38 it doesn't just want to "almost twist"... it does twist (deflect in torsion). Before that gear backlash was mentioned, and that's true, but the backlash doesn't matter to synchronization of left and right sides because there are no gear transfers between them.
I had the same thought about the gear lash, it doesn't matter!
I can explain the expression "tonneau cover": to answer that we need to go back to the early days of cars and the dawn on automobile racing. In the early 20th century, car manufacturers began offering options and configurations for their models, (remember that people used to buy a chassis and engine, and then go to a body shop to finish the car) and one popular option was the ‘tonneau.’ Initially, the term was used to designate an open, rear passenger compartment - typically rounded like a barrel. These tonneaus often included soft leather coverings to protect the compartment when not in use.
The term tonneau cover would later be adopted by racers during the early Bonneville Salt Flat days when hotrodders would cover up open areas of their vehicles to reduce wind drag.
Thank you for this video :)
You're Welcome!
You could add a drive gear to the center of that rod and add a second rod with a gear from the motor and drive the main rod from it's center. Then any twist in the main rod would be equal at both ends assuming friction on both ends is equal. This thing really looks like it will only be suitable for people who keep their truck in a clean garage. Here in the northwest fir needles combined with the rain in winter will be a huge problem for one of those left outside for any length of time. Maybe they should sell a Rivian branded tarp to throw over it.
Wonder how that was supposed to work with the introduction of any snow and ice build up. Even if you clear it it will still buildup somewhat.
Great job, thanks.
Thanks for watching!
I wonder if they considered the garage door style: spring loaded cable on either side for stability and a center mounted motor.
Or keep the motor in the same location but have a parallel half shaft from the drive motor that engages the full shaft at the center, thereby, splitting the torque from the center, eliminating the twist. More parts but within the form factor.
@@jasonhunt007 Yeah but bigger diameter of shaft should be enough to limit torsional twist. Also adding bigger teeth should eliminate any extra protrusions into already small truck bed without moving motor into the middle.
great use of "bits and bobs" Sandy would be proud
You had mentioned a solution being dual synchronized motors. I think that would address a lot of the problems. As well as removing the requirement for the shaft entirely. That idea has my vote. Are we taking votes?😂
Bigger shaft its much much cheaper, easier and not so hard to design it right. Clearly those doors were after thought for Rivian. Afterall they are new compay.
I’d add a PTFE strip to each track on either side to reduce friction and wear, also maybe the better tooth engagement, I would also look at maybe a different spring arrangement, possibly the plates on hydraulic struts like a hood/bonnet.
no space for struts. Leaf spring is compact solution. They just need make better surface interfacing as u mentioned already. Or just give up and make totally different cover system. Strong fabric roller mechanism would already suffice for its role.
Add another gear wheel on both sides to drive the slides and increase the diameter og then rod would help. Furthermore redesign the spring so the pressure plate does not need to slide and maybe add a pulley that pull the spring down when the rod rotate to retract.
Looking at the roll up and storage mechanism for the bed cover.........makes me wonder what the actual mean time to failure will be as well as the overall failure rate. Seems like it's too complicated to survive in the wild.
Looks like they'll have to replace everyone of them with new versions and very soon.
It’s called planned obsolescence, they know it will fail.
The electric motor and worm gear is an entry step motor from an rv, 100%, and they are a failure point.
Need a KISS system EG mechanical , manual. Ditch the motor altogether.
The variability of the distance between the side rails could cause pinching. Which could bind the slates and cause the gear teeth slip that you mentioned. I like the idea of greater engagement to prevent slip but can see how that may have been designed in as a clutch or fail safe point.
I enjoyed the pointer to the Poka Yoke concept.
Another option would be to allow the driven-side gear to have some spring-regulated slack up to one tooth total travel. This would allow the driven side to delay and compensate for the bar twist dynamically.
The rod would be driven by a gear, then a spring-loaded gear would be adjacent to it to drive the near-side action and the rod would transfer the torque to the far side. The cover rigidity would reinforce the spring stiffness so would push and relieve the built-up spring tension to dynamically compensate for the rod-twist.
This fix would be cheap to implement with minimal other changes. Changing the gear profile for a deeper bite on top of this would be a very welcomed change, for sure...
Putting the motor in the middle would give nominally equal twist, however there would be minimal dynamic compensation for differential friction from the tracks... but the motor in the middle and then both track gears being spring-loaded on top of the profile changes would provide a very effective fix.
They also have an issue with their accelerator peddle breaking. Hopefully they will get a fix for that too.
OTA will fix it. Lol
For a smaller diameter circular design, Rivian may test using a quite fine stainless steel “linked” mesh, a.k.a Milanese style steel mesh.
Then having the mesh molded with silicon rubber with the suitable properties = heat and cold-resistant, UV-resistant, low aging, etc.
It seems like a fair challenge to balance the retraction performance where you want a light spring tension with the extension performance, where you need strong spring tension. They also get binding when the slats thermally deform and try to retract into the tight entrance to the cartridge. Seems like a second motor would give you added torque to overcome the spring tension but wouldn't necessarily improve binding or synchronization. I'm surprised Rivian hasn't yet rolled out the manual cover.
I wonder if it's possible to adjust the spring tension between extnesion and retraction (maybe with a driven cam). Hard to fit in such a mechanism I suspect (and make it reliably shift under max tension when fully retracted).
I think either adding a thicker cross link with a lower torque bias, or adding a mirrored second regulator in parallel would solve the misalignment. Secondly, adding roller tracks, with rollers on each slat staggered in a zig-zag pattern to allow stacking, could solve the wear problems
A motor at each side alongside having the side to side connecting bar still in place is the way to go with a fail safe so if one motor stops working they both stop til repaited. either that or somehow mount the motor bang in the middle so the push/pull force is even at both sides
Looks like when Rivian was trying to follow the Land Rover legacy (target market, design elements, off road + on road capabilities), they also ended up copying some reliability issues. The problem with this cover is that it was clearly not tested and even if they improve it, it’s going to be a nightmare for owners. Dust and tiny rock is going to get into the mechanism and with 90%+ utilization it will break. In a year, two years, or four years but it will break for sure. Guaranteed. Hope some aftermarket companies are already realizing it and will come up with replacements that would ensure replacing this won’t be crazy expensive.
Garbage is also a french derivative word that I believe nicely sums up the Rivian Tonneau. I think it will soon be on the guillotine metaphorically speaking ... The biggest challenge for Engineers "just because you can, doesn't mean you should".
you all rock, keep it up
Great presentation combo!! Really enjoying the Rivian content, the Plaid/Model Y (both) breakdowns were also awesome!! I'd love to see a Lucid breakdown especially since their CEO keeps dropping knowledge on their channels Tech Talks... Thanks Munro Live!!!
Maybe run the drive shaft (after the final gear reduction) to the centre of the bed. Then run two hollow half shaft back the the pinion gears at either side (one would have the drive shaft inside it) so that they have equal wind up under the applied torque.
About the wear and tear caused from the big leaf spring, I would have use a lifting mechanism,
using articulated arms like a front windshield wiper system.
The leaf springs compress to practically nothing. Any articulated system would need rigid components which therefore have thickness plus possibly extra thickness at any hinges. There is only enough space for the slats.
If the top of the springs had a roller mech vs. that rounded piece that drags on the other parts, that may make for a smoother action overall.
or they could dip it in nylon or other low friction material, if they don't have room for anything else
Tighten the tolerance like mentioned in the video so there are deeper slots and longer teeth on the gears. Have a rod coming off the transitional gear and have a solo drive gear that mounts to the center of the current drive rod. Would be in the center, so in theory the flex going to the drive lines would be equal. No need for a second motor, so a lower increase in cost. Might even be a solution that could shorten any recall/ warranty labor.
Second motor: bad idea, too complex to keep DC motors in sync. A hollow aluminum shaft would give you the modulus of stiffness to eliminate torsion wind-up. I agree with designing the the drive gears with deeper teeth. A higher grade plastic for the notched track such as Delrin (polyoxymethylene) could reduce wear, though Delrin is fairly expensive.
I believe this issue is fixable without having to change the packaging space or assembly procedure, though it will be more expensive to manufacture due to material cost
Nylon surfaces for friction reduction would be my fix but still, dirt will cause issues big time.
POM resin
Pretty awesome to see how this works.Need to get Mec-Gar to fix their magazine there... :D
Great presenter!
Thank you kindly!
I like the tank track sprocket idea. Coupled with a larger diameter drive tube to reduce winding while minimizing weight, along with a low force stacking mechanism the alignment issue should be manageable. For stacking I envision simple geared lifting arms on each side of the magazine, connected to the gear trains, that are timed to lower one slat thickness as each slat arrives in the magazine. The arms may require gentle springs on their top surfaces to allow positive engagement/disengagement of the slats, but wouldn't need to provide anything near the full lifting force the existing springs must produce.
This is interesting idea! Def adding complexity but would reduce wear. Essentially have the spring be pushed down a little at a time by a motor until the tunnel is fully inside and then tension is put to keep the panels from rattling....Coool idea!
Great analysis. Only thing that was still a little vague to me was how the slats become decoupled as they stack in the spring loaded chamber
Rivian has sent out emails to preorder holders stating in part:
"We recently shared with R1T owners that we are upgrading the powered tonneau cover. As we go through the process, we are removing the powered tonneau cover from production. We plan to re-introduce this feature later, but a date has not been set. For the foreseeable future, all R1Ts will come with either a manual tonneau cover or no tonneau cover.
Since you have selected a powered tonneau cover, your configuration will need to be updated to either a manual tonneau cover or no tonneau cover. It’s important to note this choice will not impact your delivery timing estimate coming later this month."
Looks like a warranty event waiting to happen.
Already happening. That's why they made it an option instead of standard. Hoping less people buy it. Less issues to deal with. Those that do buy it pay $1500 so they cover that cost it seems.
@@BFArch0n Rivian has only delivered R1Ts with this option equipped so they are still being installed with this revision on every truck delivered. If you order without the powered tonneau, you aren't getting a truck at the moment.
Instead of moving the motor to the middle or adding a second motor, just run a rod from the side motor to the middle where it gears into the full length rod.
its a really cool design for the stacking etc. I hope they can iron out the functionality
Center drive is the way to go, but leave the motor where it is and run a jackshaft out to the middle.
Why not drive the shaft from the center? Less expensive than a second motor, synchronization solved. And the second tonneau spring doesn't need to be full width. Taper the sides of the second spring to make the spring force variable as it compresses. This is done in older firearms to produce equal cocking effort throughout hammer travel when using leaf springs.
They could wrap a tonneau cover around the gear tunnel, the style would be more like the cybertruck's tonneau with connected sections. The gear tunnel would be lined with plastic with drains in the wheel wells. The gear tunnel would be a tube with an outer rail to guide the tonneau cover in. The length of the gear tunnel works to completely store the tonneau cover.
Scott, let Kevin speak!
Also, I’m wondering if the RCA would point to skipping gears because of the high spring pressure requiring the system to do a lot of work.
The spring steel was probably sized for a static system. I bet they had to double the spring steel to keep the collapsed from bouncing around while the car was on the road, going over bumps.
Leave the motor where it is, but add another shaft right next to the existing one, and put two little mating gears at the middle of each shaft. The motor now only drives the new shaft, and the new shaft drives the old shaft *from the middle* via those two little gears - now you should have the same twist at each end where the old shaft drives the slats.
You beat me to it 🙂They should treat the main shaft as a torsion bar, and if driven from the middle, it should result in almost identical and synchronous torque on both ends. This will greatly reduce the discrepancy on both ends.
Put a center motor parallel with a pinion gear to put a center drive and balance your backlash and torsional deflection.
A great solution if they had the packaging space.
@@kschleic9053 ... and I doubt they do. The downside of space optimization on generation 1. They've left themselves with no option to retrofit a new solution for the current design. I see them having to design a fix that intrudes into the gear tunnel that means they ALSO have to redesign their $5k camp kitchen. 😬
I appreciate all the consideration on how parts are manufactured, like the powdered metal gearing. Any idea what plastics they used? Maybe show how a force gauge could show the spring rate?
Great review and assessment team Munro! Thank you. Being a new auto company, re-engineering everything from the ground up is no easy task. Tesla from the start focused on simplicity and part reduction, where Rivian’s initial approach was the opposite.
Dig the new intro.
Thanks Eric
Closing note:-have a great day!, when I am about to sleep at midnight. 🤣
I would have designed the slats smaller and used a roller-style spool. Plus, I would have routed the cover down before spooling, which means the spool would be smaller. I would avoid two motors because of the potential synchronization issues. Instead, they could use a bigger cross shaft to minimize angular deflection between the driven gear and follower gear. Another option is to run a shaft from the motor to the center of the vehicle in order to spin the cross-shaft from the middle as opposed to from the end.
THANK YOU!!! I've been wanting to see this. I'm stuck with my bed nearly covered completely. I need to get the slats back into the storage container so I can at least use my truck bed. But this is the only think I'm not happy with. Otherwise my R1T has been perfect.
Pretty big thing though and sorry to say there will be more ...
Great tarpan and discussion! Was wondering if using helical gears and racks would provide more consistent grip surface and help prevent slip.
Helical racks would have to be even shallower though and require even tighter tolerances. They would also have problems with the interfaces from one panel to the next. A straight cut gear has the advantage that the gap between panels just becomes another tooth.
I like the secondary shaft concept ONLY driving the center of the cross shaft instead of current setup driving only one side.
@ 0:21 Going by looks, I thought this was going to be the Munro Live Friday Table-tennis Tournament.
Nice show down of the mechanism and how and where it fails.
I just wondered, could they introduce a secondary drive and keep this connecting rod to just transfer the rotation without the load. So the rod will stay connected but on the secondary side there will be no mechanical connection but instead there could be a rotary encoder which will control the secondary drive. This way you will have no twisting of this rod and also no fancy controlling to sync the two drives. But on the other hand I habe no idea if this dependance of such a secondary drive would be a smart design choice.
Some what unusual that the axle rod wasn't driven from the center as noted - would keep the motor mass central too. At a guess, Igus could have supplied many parts off the shelf that have been tooled up also.
Great video, one questions I would have could you add a half shaft with a geared to the main shaft at the center? So the one motor would still be used and note moved to the center but the half shaft would move the movement of the gear to the center of the main shaft equalizing the torque on the main shaft.
Could they but an idle bearing above the drive sprockets so the cover couldn't move out of the sprocket?
I'd recommend canted worm gears and Teflon coat the slat slots to take up the friction. Most of the other parts could be carried over as the worm gear would minimize twist lash due to reduced ratio. The system would never misaligned, force of push on the slats would be increased likely 2X and again alignment would be far less an issue.