42129 - 4x4 Mercedes-Benz Zetros

[Citromon]

I'm sorry, but what "alternative control" on the back means? A gearbox? 

[Maaboo the Witch]

Just now, Citromon said:

I'm sorry, but what "alternative control" on the back means? A gearbox? 

It means a different control interface.

[Ngoc Nguyen]

Just now, Citromon said:

I'm sorry, but what "alternative control" on the back means? A gearbox? 

Probably a joystick-ish control like that in the 42124 profile.

[Citromon]

Just now, Maaboo35 said:

It means a different control interface.

O. I was hoping for something not depending on a phone) Thx.

[gyenesvi]

12 minutes ago, Gray Gear said:

@Andman while that would be cool it could also damage the drivetrain is on wheel is spinning freely at max rev and you suddenly bust in the difflock.. that could send quite the shock strough the drivetrain.

If it's the central diff, then one wheel cannot spin freely, only two wheels, one front and one rear, right?. And it's quite unlikely that the model would be standing on two wheels and two would be in the air..

Edited July 2, 2021 by gyenesvi

[Maaboo the Witch]

4 minutes ago, Citromon said:

O. I was hoping for something not depending on a phone) Thx.

Yeah. That ain't happening.

[Zerobricks]

38 minutes ago, Gray Gear said:

@Andman while that would be cool it could also damage the drivetrain is on wheel is spinning freely at max rev and you suddenly bust in the difflock.. that could send quite the shock strough the drivetrain.

I doubt you could generate such shocks with low powered L motors... I think diffs locks are linked to the gearbox and you switch all at once. 

[blondasek]

13 hours ago, Bartybum said:

Photos don’t change my opinion of the set (still don’t care for trial trucks, would’ve far preferred a 6x6 pneumatic crane truck with RC drive), but Grohl’s definitely done a hell of a job designing this given the constraints he has to work with, and that’s without even taking into account the redesign from 6x6 to 4x4.

I am 100% sure that he will make a dragon out of it

[Gray Gear]

@Zerobricks maybe the 2 Motors for drive arn't that stron, but the small bevel gears in the diff arn't strong as well. Over time some damage could happen.

And I agree, it would make sense to lock the diff in low gear, and open it when driving "fast"

[Ngoc Nguyen]

But why is diff lock required to climb slope?

[AVCampos]

11 minutes ago, Ngoc Nguyen said:

But why is diff lock required to climb slope?

 

1 hour ago, AVCampos said:

Maybe during a climb the weight shifts to the rear wheels and, without a central diff lock, all the power goes to the slipping front wheels?

[Timorzelorzworz]

I do not think that this model uses a gearbox for speed transmission like the Volvo. The back of the box has no information about that. One L-motor for steering, one for each axle to drive without the need for center differential - same setup as 42099. The medium motor is an addition to lock the differential, but only in the rear. TLG finally has figured out that one port on the C+ hub is spare that can be used. That's all the magic within this model as successor for 42099.

[allanp]

1 minute ago, Timorzelorzworz said:

I do not think that this model uses a gearbox for speed transmission like the Volvo. The back of the box has no information about that. One L-motor for steering, one for each axle to drive without the need for center differential - same setup as 42099. The medium motor is an addition to lock the differential, but only in the rear. TLG finally has figured out that one port on the C+ hub is spare that can be used. That's all the magic within this model as successor for 42099.

I don't think this is the case. It looks like the drive motors are in the main body of the vehicle, which is much more realistic and will offer better performance than mounting completely separate motors on the axles. Along with the newer diffs and 42099 hubs I'm expecting this to crawl better than even a low geared 42099, providing this model also has sufficient gearing.

[Brickend]

My concern is that one motor is orientated to drive the rear and the other is spun 180 degrees to drive the front, both from the center position.

 

[valenciaeric]

11 minutes ago, Timorzelorzworz said:

I do not think that this model uses a gearbox for speed transmission like the Volvo. The back of the box has no information about that. One L-motor for steering, one for each axle to drive without the need for center differential - same setup as 42099. The medium motor is an addition to lock the differential, but only in the rear. TLG finally has figured out that one port on the C+ hub is spare that can be used. That's all the magic within this model as successor for 42099.

I think that the medium motor drives the winch and locks the diff. Maybe there are 2 L motors working together to power the centre differential and a third for steering?

[Andman]

1 hour ago, Gray Gear said:

@Andman while that would be cool it could also damage the drivetrain is on wheel is spinning freely at max rev and you suddenly bust in the difflock.. that could send quite the shock strough the drivetrain.

Easy to handle:

1. Condition for diff lock becomes true
2. Stop motors
3. Engage diff lock
4. Start motors slowly again

I'm hoping for something like that. But the least we can expect is a manual diff-lock for the rear axle (the front axle doesn't seem to have one). Every automatism is candy on top.

Update: Just checked the images again. I'm pretty confident that there is no diff lock for the front axle, since the diff is enclosed by a 5x7 frame. There is simply no room for one.

Edited July 2, 2021 by Andman

[Ngoc Nguyen]

But if each axle is powered by its own motor then there's no central differential to be locked, isnt it?

[AVCampos]

That's true, but do we know that's how this set's laid out?

[syclone]

@AVCampos Pretty sure the front axle has a motor on it, then there's another motor for the rear axle mounted in the middle of the chassis....

Edited July 2, 2021 by syclone

[Andman]

14 minutes ago, Ngoc Nguyen said:

But if each axle is powered by its own motor then there's no central differential to be locked, isnt it?

They still cloud be interconnected by a diff lock. But i doubt it. We'll see. Can't wait to see some reviews. But after all, the diff thing is something, which could be modified. What I'm more interested in is the parts color quality. I'd rather not pay premium prices for non-premium quality.

7 minutes ago, syclone said:

@AVCampos Pretty sure the front axle has a motor on it, then there's another motor for the rear axle mounted in the middle of the chassis....

The motor for the front axle is directly above it. You can see the typical shape of the motor between the colors LBG and DBG. Oh wait... that more likely the motor for steering.

Based ion the images i have seen, it seems that both L motors the in the middle below the gearbox  have their output pointing backwards, which makes me wonder how the drivetrain is designed.

Edited July 2, 2021 by Andman

[kbalage]

Here's everything I can share about the set at the moment, with some extra coming straight from the LEGO Fan Media Days designer interview such as new parts and other background information :)

 

 

 

[Andman]

Thanks @kbalage for sharing the video and info. So there is a remote controlled central and rear diff lock. My interpretation is that it is not automatically engaged, isn't it?

[kbalage]

@Andman there is a button for it in the Control+ profile as I saw on the photo. But nothing prevents us to create a code that automatically engages it if needed ;)

[syclone]

23 minutes ago, Andman said:

The motor for the front axle is directly above it. You can see the typical shape of the motor between the colors LBG and DBG. Oh wait... that more likely the motor for steering.

Based ion the images i have seen, it seems that both L motors the in the middle below the gearbox  have their output pointing backwards, which makes me wonder how the drivetrain is designed.

Seems as if I completely forgot about steering... oops.

-----------------------------------

Thanks for the detailed information, RacingBricks, seems that Zerobricks was right in regards of CV joint... too bad they're so big, and completely useless for a small-scale MOC. That change for C+ hub... I'm dumbfounded tbh, perhaps some Karens were worried for their little kids.

Also find it extremely funny that all these "high-tech" motors are used only to limit the steering angle... even the diff-lock uses a "dumb" motor with a clutch lol. 

[Interceptor]

Thank you @kbalage for the great and informative video. Could you please test in the upcoming video review of 42128 that if it can actually lift and tow 42078 truck?