[MOC] Mercedes-Benz Zetros 2733 6x6

[Ngoc Nguyen]

 

CONCEPT

When I first learned that there would be a Zetros in the lineup of summer 2021, I looked it up on Google, and the majority of image results showed the 6x6 variant. Then the prelim image was leaked and it was also a 6x6, so I was very eager for it.

Then the official images for 42129 were released, aaand it was a 4x4.  That was the first letdown about 42129. The second letdown to me is that the grill just doesn't look like a Zetros's grill. Don't get me wrong about 42129. I actually like 42129 as a set, because the building experience is pleasant, and the set has new parts and cool functions. It's just that as a Zetros, 42129 doesn't score highly for me. Not to mention, 42129 isnt a very interesting to do a mini replica from. It's just a 4x4 with two differential locks. So I decided to do a mini replica of the preliminary design instead, and incorporate the features of Zetros 2733 as well as those from the official 42129.

 

DEVELOPMENT

HOOD

One significant shortcoming of my design process is that there's no place for stickers, which means I can't put the word "Zetros" or the Mercedes-Benz logo anywhere on the model. Therefore, I strived to replicate as closely as possible all the distinctive features of the real model, so that the model looks like the Zetros at first sight, and it doesnt need any name or sticker to tell viewers what it's supposed to represent.

The first distinctive feature of the Zetros is the grill, which in the small scale turns out to work better than in the original 42129's scale. I also use the #5 connectors and the slope pieces to create the slants. In the end I'm very happy with what I achieved. You can see the comparison here.

Of course the hood must be tiltable, which reveals a working inline 6 engine.

 

CABIN

The second distinctive feature of the Zetros is the cabin's shape. The side walls are slanted, and the sides of the roof are also slanted. 

 

In the official 42129, the walls aren't slanted, while the sides of the roof are designed with curved panels, which isn't very satisfying to me. My solution for the cabin shape is as follows.

 

Because of the slanted sides of the roof, the only solution for the A pillar are the 6L tow ball links. This piece is until lately only available in 2 colors, DBG and Black, so to ensure the consistency of the color schemes the cabin should be built in either DBG or Black. The problem is that those colors make the model look very dull, and I don't have stickers to improve the appearances. Thanks to the recently released Mario set 71438, the 6L link is now available in Green, Orange, and Yellow, but the color option for the cabin only extends to Orange, as there are not enough connectors in Green and Yellow. However I decided to go with White, which is the color of the cabin in the preliminary design, and accept the slightly off-color A pillar in black.

 

CHASSIS

The distance between the first axle and second axle is 19 unit, and if you have followed my design journey you'll know what I think when I see that number. Of course it has to be the 3x19 frame.   So I use a pair of them as the basis for the chassis.

The chassis is 5 module tall from the drive train to the axle that drives the fake engine. Usually, to transmit motion through 5 modules, 3 16z gears are used. 

 

The problem with this is that the differential sticks out too much under the chassis. Zetros is an off road vehicle, so the ground clearance needs to be as high as possible. Of course there's no actual ground clearance with Lego trucks at the axle because of the differentials, we all know that, but it is my personal preference that at least the chassis should have high clearance, or at least nothing sticking out below. Therefore I moved the differential up 1 stud, and used the new 28z differential so that it can mesh parallel with a 20z gear in a distance of 4 stud only. And since there's still some free space in the chassis, I decided to include the center differential lock function of the official 42129.

 

REAR AXLE

 

Since Zetros is an off road vehicle, I want the rear axles to be actual live axles. This design is based on the design of the rear axles in 42043. There are spring loaded suspensions, tow ball liftarms that mimic leaf suspensions, and Panhard rods to prevent sideway swings. The only downside of this design is that the axles of the wheels will be 6.5 stud from the top, but it's okay in this case because that will force the front axle to be 6.5 studs from the top too, which means more space.

 

FAKE ENGINE

The small fake engine needs at least 3 studs around the axle for the crank liftarms to spin. That leaves a very small space above it and under the hood, so I can only use 1/2 pins. You can notice that the 1/2 pins are put upside down, with round tiles in the bottom. The reason is that this design allows a bigger area for the crank to touch the pin, and can push the pin up more easily. If I put the 1/2 pins in the upward position, when the crank liftarms spin up it will hit the stem of the 1/2 pin, and sometimes the liftarm cant push the pin up, causing a jam in the drive train.

 

FRONT AXLE

The front axle uses the usual set up of Mustang rims facing inside to allow both steering and drive. For this model, I managed to add pendular suspension to it as well. The whole axle is connected through a frictionless pin in the front and two rubber pieces in the back.

 

Even though the rim is the Mustang rim, I can still create the look of bolts on the front wheels with the help of this printed disk, which is introduced in the Voltron set.

 

FRONT BAR

Even though it doesn't look like anything significant, the design of this part is quite a challenge. It needs to be 2 stud thick to be correct in terms of proportion, but it also needs to have two lights. At the same time there needs to be a gap between the front bar and the hood, as seen in the real thing.

 

To achive all of that I used a mixture of thin liftarms and a pair of part 11455 on both sides. I really love the use of part 11455 here, because not only does it provide a pin hole in the front for the light, it also has a thin middle part, which leads to a drop in the height on the sides of the front bar, and this drop exists in the real front bar too, as you can see above.

 

REAR BED

I choose the rear bed for this variant not just because the preliminary 42129 design has the rearbed, but also because of another influence. In my first time visiting the official Zetros page of Mercerdes Benz, I was struck by the image of this 6x6 Zetros with a rear bed running through the desert. It has got to be the coolest Zetros I have ever seen.

 

Therefore I want my Zetros to be like this variant too. You can see that I replicate the roof light configuration of the variant above in my model. 

 

ADDITIONAL FUNCTION

Well, now that the truck has 3 axles, working engine, lockable center diffential, openable hood, distinctive features, that should be enough to finalize the model right? Right?

Nah, I didnt settle with just that. Markus once said, Technic is all about the cool functions, so I want to put more than just the bare basic functions into the model. At this stage, here's the model. What else can be put in? Where else can be put in?

 

The answer: Inside the cabin. There are still unused spaces in there, so I put a working steering wheel AND make it adjustable. The steering wheel is geared up too, so that it spins more when the wheels turn, just like in the real vehicle. It doesnt take much more work, but more functions means cooler models, dont you think?

 

Here's the diagram of the drive train and steering train.

 

Overall I'm very happy with the final result, and I can finally have for myself the variant of Zetros that I want.

 

FUNCTION SHEETS

 

 

COMPARISON

 

INSTRUCTION: https://reb.li/m/209451

 

 

Edited January 29 by Ngoc Nguyen

[Thirdwigg]

Again, great job. My kind of build too, smaller, with lots of manual features. Any place to add a winch? 

[Ngoc Nguyen]

4 minutes ago, Thirdwigg said:

Any place to add a winch?

Well about that...

Spoiler

Yes there is, and the initial version has a winch, a control knob, and a ratchet as well, but I removed them so that I can save the winch function for the 6x6 Expedition Vehicle variant 

 

[Ngoc Nguyen]

32 minutes ago, Thirdwigg said:

My kind of build too, smaller, with lots of manual features.

I plan to do what you did for the Unimog: build a lot of variants! 

[jorgeopesi]

Good and extense explanation,  I do not usually like complex mini MOCs because one of my priorities is the sturd construction but talking about aestethics you have talent no doubt, it is difficult to achieve those forms with just a few pieces.

[Rebel_Lego]

Nice model! I have one remark: the window on the side is shaped a bit weird... I think it has to do with the thick liftarm on top. Maybe it would be better as a thin liftarm if that's possible 

[Aurorasaurus]

What an impressive build! It feels like you're aiming to become a real LEGO designer. Brilliant presentation too, sharing so much information is very welcome and appreciated.

[Ngoc Nguyen]

5 hours ago, jorgeopesi said:

I do not usually like complex mini MOCs because one of my priorities is the sturd construction but talking about aestethics you have talent no doubt, it is difficult to achieve those forms with just a few pieces.

Thanks a lot! I was lucky to find the pieces that fit what I need foor this model.

 

6 hours ago, Rebel_Lego said:

Nice model! I have one remark: the window on the side is shaped a bit weird... I think it has to do with the thick liftarm on top. Maybe it would be better as a thin liftarm if that's possible 

Yeah you;'re right. Originally I want to put mirrors into the doors, so the top side has to be thick to support it. Later I removed the mirrors because on the passenger side, the mirrors will clash with the side tubes, but I forgot to change the door to make it look better.

 

4 hours ago, Aurorasaurus said:

What an impressive build! It feels like you're aiming to become a real LEGO designer. Brilliant presentation too, sharing so much information is very welcome and appreciated.

The prospect of a real Lego designer sounds cool but in reality I would be limited in terms of subjects and pieces, which doesn't soud like fun. I did all of these models mostly to have fun, so if it's not fun I'm not gonna do it. 

[Thirdwigg]

20 hours ago, Ngoc Nguyen said:

I plan to do what you did for the Unimog: build a lot of variants! 

I look forward to all of them!

[Ngoc Nguyen]

Usually MOCs like this don't sell but this one got its first sale today yay!