Off Road Dreaming

TyPope

Well-known member
First Name
Ty
Joined
Mar 31, 2020
Threads
19
Messages
1,641
Reaction score
2,757
Location
Papillion, NE
Vehicles
'18 F150, '23 MY, '24 CT, '23 Maveric hybrid soon
Occupation
Operations Planner
Country flag
Given that the CT requires the larger casting machine in order to actually make a production version, how long do you think it will take before we start seeing testing on actual vehicles? I know there is SOME testing that can be done but there are limits and I'm interested to see some of the more extreme testing... rock crawling type of stuff.
Sponsored

 

JBee

Well-known member
First Name
JB
Joined
Nov 22, 2019
Threads
18
Messages
4,752
Reaction score
6,129
Location
Australia
Vehicles
Cybertruck
Occupation
. Professional Hobbyist
Country flag
Both the Suburban and the Jeep had only traction problems.

I think the CT, being no larger than the suburban (which fit the trail), having better clearance than the suburban (which didn’t bottom out), and more powerful than the jeep (which eventually did pull itself up), has to only find better traction than the jeep or suburban.

And as for the traction, while the size and contact patch of the tires will be a big variable, just as important is weight over the tires.

That Cherokee has large, gripping, tires but almost no weight over its rear tires, so they just spun.

The weight and weight distribution of a CT I think let’s it crawl this trail assuming any modestly trail worthy 35” tire.

I await your testing of this!
There's a few dynamics at play here which I will try to identify and compare to how I expect the CT will work. Just for fun..

The wheelbase of some of the vehicles match the terrain undulations better. So for example: instead of having a rise happening both at the same time on the front and rear axle, a shorter wheelbase could get it's front or back axle up first, which then helps get the next axle up etc. The opposite can also be true, giving the longer wheelbase an advantage, by getting more vehicle mass over the top of a ridge on a section where the front could be level.

Then there's tyre pressure that also helps the tyre deform over the rock shape for better grip. The surface was a combination of loose sand in pockets and solid rock, which means picking an ideal tyre type is a bit harder, a smoother tread pattern but low pressure capable tyre would likely work best. I don't think the Suburban tyres were a good fit, and tyre diameter would also play a roll here.

As for overall weight and distribution, the hill incline would naturally push the center of mass backwards, putting more weight on the rear axle. The ICE weight in the front would be beneficial here on the incline sometimes. The problem is here though that it is not always beneficial, for example when the front is clear but the rear still has to climb. In that situation the front needs to pull the rear up, so more front weight would be better. Having weight higher up in the vehicle will also mean the center of mass will shift more on an incline, and make the vehicle more prone to tip sideways.

The alternating steering angle, in particular locking to one direction would have helped put more pressure on the steering wheels by only exposing side of the tyre to the ridge, meaning less surface area, but same force from the vehicle weight. On a hard rock surface less contact patch can be better if it's not wet or covered in dirt. The other issue that can change traction is if the rock is shaped the same as the tyre or has a bump.

The reversing and launching into the ridge or "rocking" helps increase traction by artificially increasing the force on the tyre contact patch by using vehicle momentum. Even doing a burnout on the rock helps in that it deposits some rubber on the rock for extra traction like on a drag strip.

But if we had a CT going up that path, the situation would be significantly different:
  1. The independent air suspension would distribute the vehicle weight evenly across the 4 wheels until it reaches maximum suspension articulation
  2. The air suspension could level out the vehicle whilst climbing, placing more weight over the front for better overall traction, and stopping the CT from tilting sideways and slipping down
  3. With active damping the suspension could stop the suspension from jumping by increasing the damping rate
  4. The 4WS will help in positioning the CT in the right place to climb, and to change direction in times of low traction and also vary the wheelbase to a certain degree by crab steering, it will also improve rear axle tracking and allow for turning without slip.
  5. The net effect of the above improved traction, would make it possible for the toque vectoring to apply force up to the traction limit of each of the tyre. This means the maximum possible amount of force can be applied to transverse the incline and terrain. This could be from 2-4times as much tractive force in comparison to a open diff indpendant/live axle steel sprung competitor. Torque vectoring will also help steer.
  6. Onboard sensors could also be used in conjunction with a CoG calculation to avoid roll-overs, ToF cameras can do terrain mapping and route optimisation, 360 camera for driving even without a spotter etc
Overall a much better experience than watching those random buckets of mechanical bits climb a wall like a steam engine. :D
 

Crissa

Well-known member
First Name
Crissa
Joined
Jul 8, 2020
Threads
126
Messages
16,229
Reaction score
27,097
Location
Santa Cruz
Vehicles
2014 Zero S, 2013 Mazda 3
Country flag
Given that the CT requires the larger casting machine in order to actually make a production version, how long do you think it will take before we start seeing testing on actual vehicles? I know there is SOME testing that can be done but there are limits and I'm interested to see some of the more extreme testing... rock crawling type of stuff.
They don't 'need' the gigacasting machine to make test articles.

-Crissa
 


JBee

Well-known member
First Name
JB
Joined
Nov 22, 2019
Threads
18
Messages
4,752
Reaction score
6,129
Location
Australia
Vehicles
Cybertruck
Occupation
. Professional Hobbyist
Country flag
I feel personally attacked by that one. :ROFLMAO:
Sorry didn't realise you were an old timer running out of puff! ;) ;)

You can always roll down the hill section after being dragged kicking and screaming up the hill by a CT. I mean your bucket of bits ICE car of course! :ROFLMAO:
 

JBee

Well-known member
First Name
JB
Joined
Nov 22, 2019
Threads
18
Messages
4,752
Reaction score
6,129
Location
Australia
Vehicles
Cybertruck
Occupation
. Professional Hobbyist
Country flag
Of course that's can damage the trail, more quickly ruins the tires, and is also gross.

-Crissa
So wicked gross? So absolutely awesome in boomer speak? 😁:ROFLMAO:
 

TyPope

Well-known member
First Name
Ty
Joined
Mar 31, 2020
Threads
19
Messages
1,641
Reaction score
2,757
Location
Papillion, NE
Vehicles
'18 F150, '23 MY, '24 CT, '23 Maveric hybrid soon
Occupation
Operations Planner
Country flag
They don't 'need' the gigacasting machine to make test articles.

-Crissa
It seems it would be impossible to test the structural engineering without the structural parts required to test. They can get close with a one-off casting of the front and rears with sand casting or clay casting but the structural integrity of the metal would be different there. Overall fit and finish? Sure, they can test that. Part interoperability? Sure. Structural integrity? Nope. That will have to wait. I suppose they could get close enough to declare a proof of concept and it may not take very long at all to prove their analysis is correct... which I suspect will be the case. Still, it'll be nice seeing the first "real" Cybertruck being wrung out.
 

JBee

Well-known member
First Name
JB
Joined
Nov 22, 2019
Threads
18
Messages
4,752
Reaction score
6,129
Location
Australia
Vehicles
Cybertruck
Occupation
. Professional Hobbyist
Country flag
It seems it would be impossible to test the structural engineering without the structural parts required to test. They can get close with a one-off casting of the front and rears with sand casting or clay casting but the structural integrity of the metal would be different there. Overall fit and finish? Sure, they can test that. Part interoperability? Sure. Structural integrity? Nope. That will have to wait. I suppose they could get close enough to declare a proof of concept and it may not take very long at all to prove their analysis is correct... which I suspect will be the case. Still, it'll be nice seeing the first "real" Cybertruck being wrung out.
You can just cnc machine the form instead of cast, out of similar material. That will get you within 10% of cast spec.
 

Crissa

Well-known member
First Name
Crissa
Joined
Jul 8, 2020
Threads
126
Messages
16,229
Reaction score
27,097
Location
Santa Cruz
Vehicles
2014 Zero S, 2013 Mazda 3
Country flag
It seems it would be impossible...
No, because that's just a method for making a part. Test articles (and even production) are made with stand-in parts all the time. See also the Model Ys shipped with extruded molding when the made-to-fit piece wasn't available. Parts are swapped between stamped and soldered and welded and cast all the time. How you make any part isn't that important to the end product.

-Crissa
 


TyPope

Well-known member
First Name
Ty
Joined
Mar 31, 2020
Threads
19
Messages
1,641
Reaction score
2,757
Location
Papillion, NE
Vehicles
'18 F150, '23 MY, '24 CT, '23 Maveric hybrid soon
Occupation
Operations Planner
Country flag
No, because that's just a method for making a part. Test articles (and even production) are made with stand-in parts all the time. See also the Model Ys shipped with extruded molding when the made-to-fit piece wasn't available. Parts are swapped between stamped and soldered and welded and cast all the time. How you make any part isn't that important to the end product.

-Crissa
No, because that's just a method for making a part. Test articles (and even production) are made with stand-in parts all the time. See also the Model Ys shipped with extruded molding when the made-to-fit piece wasn't available. Parts are swapped between stamped and soldered and welded and cast all the time. How you make any part isn't that important to the end product.

-Crissa
...unless it is structural. You can get close but not quite all the way there with machined parts. We'll see most testing without but Tesla WILL eventually have to test with the real deal (That's what I'm really talking about... Once they are using real ones for testing, they'll be closer to making mine!)
 

Crissa

Well-known member
First Name
Crissa
Joined
Jul 8, 2020
Threads
126
Messages
16,229
Reaction score
27,097
Location
Santa Cruz
Vehicles
2014 Zero S, 2013 Mazda 3
Country flag
'Structural'?

Everything is structural, in optimally built.

They still change things all the time.

No, they don't need to gigacastings to create test articles. How do you think they design the castings in the first place?

-Crissa
 

CostcoSamples

Well-known member
First Name
Trevor
Joined
Feb 24, 2020
Threads
2
Messages
245
Reaction score
555
Location
Alberta, Canada
Vehicles
Mazda 6, Odyssey
Occupation
Engineer
Country flag
If I had money to burn I would totally take a CT4 on these trails! But since I don't, I will stick to modest off-road trails where the biggest risk to my precious machine is running out of power in the wilderness.
 

JBee

Well-known member
First Name
JB
Joined
Nov 22, 2019
Threads
18
Messages
4,752
Reaction score
6,129
Location
Australia
Vehicles
Cybertruck
Occupation
. Professional Hobbyist
Country flag
If I had money to burn I would totally take a CT4 on these trails! But since I don't, I will stick to modest off-road trails where the biggest risk to my precious machine is running out of power in the wilderness.
Where's the fun in that?

You know you should resist the force of "your precious" right? 😎

Once I've done a lap you can have a go in mine with me as spotter. That way we both get a thrill! Lol :eek:
Sponsored

 
 




Top