[MOD] 42129 Mods and Improvements

[thurd]

3 hours ago, gyenesvi said:

One more alternative that I'd consider is a Defender + 42099 Extreme off-roader. With those two you get most of the goodies, but instead of 3 L motors, instead you get 1L + 2 XL motors, which is also good for offroading (plus you get larger wheels as well). Then if you really need that, you could buy 2 more L motors separately.

Here you can check what offroaders I managed to build from these 3 sets, may be useful as reference or inspiration:

https://rebrickable.com/users/gyenesvi/mocs/

That's a really good idea. I've been eyeing the Defender since it's extremely cheap compared to the number of parts it gives (it even beats the current Tow Truck).

 

I never considered the 42099, something about the Zetros speaks to me and the amount of mods and upgrades (in this thread also) is very tempting, but maybe I should look around if there aren't any good deals. I'll certainly look at the MOCs you've built, inspiration is always nice. Thank you for your help! 

[Johnny1360]

I feel like it's worth mentioning the current buggy, 42124, as a parts pack too. Relatively inexpensive way to get the smart hub and two L motors. You also get a fair amount of useful parts, new differential, new tires, a couple crossover beams and a meager amount of suspension parts to boot. I bought one just for parts and may get another.

[Igor1]

A few dull pictures, just to get back on topic...

I sketched the grille tonight, but the duckling thinks it can be done better.

[Igor1]

https://rebrickable.com/mocs/MOC-100998/igor1/mercedes-benz-zetros-42129-alternative-hood/

Edited February 7, 2022 by Igor1

[R0Sch]

What about the official LEGO changes in the instructions? I think it's at least worth to mention them here, since they did fix 3 issues: hood, door and emblem. Sadly not the more technical ones like rear suspension and axle. That one extra 16T gear makes all the difference.

[Igor1]

@R0Sch Correction of axes was discussed in the topic below.

 

1. I assembled my 42129 with front axle from @Attika.
2. And in the rear axle I added an extra gear, according to the video instructions from @rm8.

Edited February 7, 2022 by Igor1

[MikeTwo9398]

After several attempts, the 42129 was converted to a 2-speed truck and still kept the differential lock.

The first attempt was quite successful, however after a while the truck was no longer able to climb, although the speed was lower and the torque was higher.

So I had to start again.

 

This is the final result:

Gears for the speed and differential lock

Rear axle:

Some small adjustments of the rear axle. An extra gear at the differential to prevent slipping gears while climbing.

Doors:

A simple pin to prevent the doors from opening

Bonnet:

A small adjustment of the engine hood, a simple small black round stud of 1 in 2 places (one was a spare pice in the box).

 

Driving the truck:

The Control+ app from Lego of the 42129 can be used as usual.

With the differential unlocked the truck has a slightly higher speed than normal and is able to handle simple low obstructions.

Driving through grass is also perfectly possible.

When switching on the differential lock, the speed is also reduced to the speed as the original 42129 has.

 

Here you can see the truck in action.

 

 

At Rebrickable you can find the free building instructions.

For building this mod I use below extra parts:

 

 

 

[2GodBDGlory]

Wow, good work! That looks very compact, and adds a great feature the original set was missing!

[masterventris]

Has anyone tried replacing the planetary gear hubs for the basic hubs? You lose the 4:1 step down ratio which will impact the climbing ability, but the subsequent 4x increase in speed should really improve how fun the model is to drive!

[KLF]

Hi guys, please where can I download CAD file (LDraw or Stud.io) of the original 42129 Zetros? Thanks.

[2GodBDGlory]

5 hours ago, KLF said:

Hi guys, please where can I download CAD file (LDraw or Stud.io) of the original 42129 Zetros? Thanks.

This here is a good website to check out for Stud.io files:
https://fogeyman.tistory.com/

[KLF]

2 hours ago, 2GodBDGlory said:

This here is a good website to check out for Stud.io files:
https://fogeyman.tistory.com/

Thanks but can you give me English mutation?

[2GodBDGlory]

3 minutes ago, KLF said:

Thanks but can you give me English mutation?

I think there's some kind of built-in translation function on the website; otherwise Google can automatically translate that. At least, that's what I always did.

[MikeTwo9398]

On 2/1/2023 at 9:38 AM, KLF said:

Hi guys, please where can I download CAD file (LDraw or Stud.io) of the original 42129 Zetros? Thanks.

You can find an IO file on my Bricksafe page. Original is the "42129 bag 1+2+3+4+5+6.io" file. The other IO is my speed me up design.

[R0Sch]

Thanks @MikeTwo9398 for the Studio model! Looks miles better with the Audi wheels (thanks @Philo for the early model). Maybe someone can test the grip and performance in outdoor conditions. I might get 4 extra and fit them on even though 4,77€ pp. is a lot just for rubber. I don't like the smelly Chinese RC wheels I bought and they also developed white residue as if evaporating the chemicals to the surface.