Rivian's plan for Rock Crawling is a low-range crawler gearbox. Is it something Cybertruck S.B. looking at?

[FutureBoy]

Sorry I think I didn't explain exactly what a "efficiency heat map" is. The colouring scale on the graph is not heat output, rather motor efficiency. That means the red areas make less heat than the blue areas. So you want to optimise to run in the red areas to keep the motor cool.

Ahhh.... Someone seems to have forgotten that many people use red to indicate danger/heat/stop. They should have reversed the colors on the color scale. Whoever made this chart needs to learn better presentation skills.

 

[Sirfun]

Interesting article with cool photos of a bunch of EVs checking out The King Of the Hammers Offroad event recently.

https://www.optimabatteries.com/experience/blog/optima-unplugged-at-king-of-the-hammers/

 

[charliemagpie]

Chinese stock charts depict red as UP. Did my head in the first time my wife showed me.

 

[FutureBoy]

Chinese stock charts depict red as UP. Did my head in the first time my wife showed me.

Closer to the sun? It gets hot when you get close to the fire ball in the sky?
Of course it gets FREEEEEEEEZING cold first but sure.

When I was a kid, other kids in the US were told that China was the other side of the globe. Dig a hole through the center and you end up in China (you don't) and they all are living upside down compared to us (again, they are not). Perhaps the stock charts a side effect of this...

 

[charliemagpie]

Which got me thinking. I'm going there in a couple of months, I want to check if the red light is Stop or Go. lol

 

[FutureBoy]

Which got me thinking. I'm going there in a couple of months, I want to check if the red light is Stop or Go. lol

Also check which color is at the top of the signal.

I lived in Japan a long time. Back in the 70's most traffic signals were Red, Yellow, and Blue. And that's what colors people would tell you they were. In more recent years the lights have been slowly converted over to be Red, Yellow, Green. But if you ask a Japanese person, they will often swear to you that light signifying that it is ok to Go forward is Blue, not Green. You can hold up a blue paper and they will say blue. Hold up a green paper and they will say green. But ask about the light, and they will tell you it is blue. Perhaps things have changed now. I've not been back in a long time. But the whole blue light thing was always a mind bender for me.

 

[Jhodgesatmb]

I just saw this about a way to make Rock Crawling with an EV easier. Ideas on if it could be adapted to CT?

"https://www.thedrive.com/news/rivian-patents-bolt-on-low-range-crawler-gearbox-for-off-road-evs"

So they are reinventing the transfer case but multiplying it by 4? Sounds like an ugly solution and I wonder if they will get the patent given that transfer cases have been around a LONG time and work the same way. Sadly the drive shafts would have to be shortened, and I don't see a way from the drawings (though I didn't look for long) to use the normal gearbox without the 'transfer case'. I do hope that Tesla has a solution for rock crawling and that it is baked into their drive unit design.

 

[JBee]

So they are reinventing the transfer case but multiplying it by 4? Sounds like an ugly solution and I wonder if they will get the patent given that transfer cases have been around a LONG time and work the same way. Sadly the drive shafts would have to be shortened, and I don't see a way from the drawings (though I didn't look for long) to use the normal gearbox without the 'transfer case'. I do hope that Tesla has a solution for rock crawling and that it is baked into their drive unit design.

Well it's sort of a single wheel single motor transfer case which I have never seen before, so it might be new and novel. If they use planetary gears they could technically just add a plate and use the same driveshafts.

As further above, I think the CT solution is to use higher RPM but smaller dimensioned Plaid motors on all wheels, with higher ratio gears.

PS after looking at the diagram again it does look like a planetary gear. I wonder if they just block one of the sets (ring, planet or sun) to switch between low and high ratios. That would make ist super simple, tough, no clutch, and switchable whilst on the move. Maybe something CT could have too.

 

[Zabhawkin]

At first I thought these were portal axles, but apparently I was wrong. These are bolt on high/low range gearboxes. In theory they will improve their capabilities off-road. Similar devices for ICE vehicles run for $1500-2500 for one. This will require 4.

https://high-impact.net/product/rubicrawler

 

[slomo]

Rivian can't supply a full size spare with an R1T purchase. They can't supply a tonneau cover for the R1T bed. They ain't making a low range gear vehicle any time soon.

The CT is way too big and heavy as a rock crawler. Where crawler gears are used is pulling very heavy loads off road. Modern unimogs have been used to move rail cars.

 

[Crissa]

In Chinese culture, red is luck and spirit.

In Europe it's blood and danger.



-Crissa

 

[JBee]

Ahhh.... Someone seems to have forgotten that many people use red to indicate danger/heat/stop. They should have reversed the colors on the color scale. Whoever made this chart needs to learn better presentation skills.

JFYI a "heat map graph" is just a way to highlight certain variables with a colour scale. It doesn't have anything to do with heat itself, except that a variable that "looks hotter", is just more of a particular value. In this case the "hotness" is efficiency, and seeing that electric motors don't make much light, sound or other energy form to convert electrical into kinetic, it can be simply used to understand motor heat generation as well, by looking at low kinetic efficiency as high heat generation points on the graph. Ie in inverse.

In essence although an electric motor can produce high torque at low rpm, it is doing so at low efficiency, meaning that a lot of heat is being generated which can damage the motor. That's why Plaid has to prepare the drivetrain for hard acceleration by pre cooling everything. In offroad use this would be ineffective.

 

[CyberBanana]

In essence although an electric motor can produce high torque at low rpm, it is doing so at low efficiency, meaning that a lot of heat is being generated which can damage the motor.

Thanks for saying this. People need to be reminded the CT is not designed for rock crawling. It's going to do it better then stock petrol rigs but it has its flaws.

Some sort of gear box transmission would be useful if you want to do this with electric motors so you can have a good highway rpm gear ratio and a super low rock crawler gear ratio. This would be fun to have, but will probably have to be a aftermarket modification.