[MOC] Mini 42043 - Mercedes-Benz Arocs 3245

[Ngoc Nguyen]

 

2025 marks the 10th year anniversary of the release of 42043, the most iconic Technic set of the modern era of Technic. It is also my 10th year here in Eurobricks. It is no coincidence: I joined this forum because I came across Jim's excellent review of the original 42043. Therefore, nothing is more fitting that doing a mini 42043 to celebrate the occasion. This model is meant to be revealed on August 1st to match the exact date that 42043 was released, but due to delay in custom clearance, the parts to build this didn't arrive until last week, Oh well, better late than never. At least it's still 2025!

DEVELOPMENT

I know what you're thinking. It's that guy who does the mini replica again, he's probably gonna yap about how difficult the design process was, and how he overcame it, so I'm just gonna scroll through. Well then I'm not gonna bore you with that. I'll go straight up to the interesting parts.

 

THE GRILL

The original 42043, highly regarded as it is, still has some aspects that can be improved upon. For me, one of them is the grill. Mercedes-Benz Arocs almost always have 4-slit grills. I'm aware that there are version with 3 slits, but the 4-slit version is more common. So I set out to do that. The bumper has 2 slits, and the cabin has 2 slits, just like the real thing.

 

To achieve the slant in the bottom slit, I have to use some unusual connection techniques. This is how the bumper look from behind. 

 

CABIN LOCK

Another downside of the original cabin is that there's no firm point to grab it. The crane can move, the bed can move, the cabin can move. Therefore, I added the locks behind the cabin.

 

THE CHASSIS

In my previous 4 axle truck, the Iveco T-Way, I managed to put pendular suspensions into the 2nd, 3rd, and 4th axle. I couldn't add that to the 1st axle because of structural constraint. That is the limit that I'm determined to break this time, and I did it. Both front axles are steerable AND have pendular axles.

 

I'm very proud that the chassis can accommodate pendular suspension in 4 axles AND a 6 cylinder inline engine AND steering axles with two different radii AND the outriggers AND a linear actuator for the bed.

 

This is how the chassis looks.

 

CLAMSHELL BUCKET

The clamshell buckets are probably designed to be operated with pneumatic. I set myself a challenge: make it work with gears. Does it work? Yes it does!

 

Watch everything in action here:

 

THE END, OR IS IT?

Normally, that would be the end of the introduction post. But I think that much wouldn't be enough for me, and it wouldn't be enough for you either. I have done this mini replica thing for a while, and the formula is getting stale. I wanna do something different to break out of the previous boundaries. So I took a look back on the original 42043, and check if there's any other thing about it I can do. Then it hit me. Remember that thing in the back of the box? The thing that used to be a feature of Technic but is no longer since 2024? Yeah this thing.

 

So what did I do? I created a B model too!!!! Please welcome Mini 42043 B - Mercedes-Benz Articulated Construction Truck!

 

You can get both instructions here: https://reb.li/m/240252

[Ngoc Nguyen]

Big vs Small

 

[crazy technic]

yet another great looking mini model, does your B-model also use the same pieces as the A model?

[Ngoc Nguyen]

2 minutes ago, crazy technic said:

yet another great looking mini model, does your B-model also use the same pieces as the A model?

Yes it does! It's a proper B model!!

[Timorzelorzworz]

This is awesome 

[Ngoc Nguyen]

Just now, Timorzelorzworz said:

This is awesome 

Thank you! You're awesome too!!

[Jundis]

This gotta be you best model yet!

Perfect shaping and great functions, also implementing the suspension in this medium-sized model, just whoa. Hats off!

[Ngoc Nguyen]

10 minutes ago, Jundis said:

This gotta be you best model yet!

Perfect shaping and great functions, also implementing the suspension in this medium-sized model, just whoa. Hats off!

Thanks a lot!

[1gor]

Looking what you made, now I can took 42043 apart for my future project (in bigger scale). So far I didn't have a heart to take it apart, but now I know if I decide to have Arocs, there is better alternative in Volvo 42175 scale.

Looks very very good Ngoc. 

[gyenesvi]

This is wild, densely functional and premium with that B model, looks awesome! You do really take this game of minification to the limit!

[Paul B Technic]

Great work as always and I love that you also made the B model.

[J159753]

This looks wonderful, as ever – congratulations!
(Can I raise a side-issue, though? Imgur is no longer available in the UK, and Imgur-hosted images are not visible on UK computers. Please could posters consider using other image services if it's convenient for them to do so? Thanks! https://help.imgur.com/hc/en-us/articles/41592665292443-Imgur-access-in-the-United-Kingdom)

[Ngoc Nguyen]

8 hours ago, 1gor said:

Looking what you made, now I can took 42043 apart for my future project (in bigger scale). So far I didn't have a heart to take it apart, but now I know if I decide to have Arocs, there is better alternative in Volvo 42175 scale.

Looks very very good Ngoc. 

Thank you! If you don't have any parts you can build the Arocs semi truck in the B model as well.

 

7 hours ago, gyenesvi said:

This is wild, densely functional and premium with that B model, looks awesome! You do really take this game of minification to the limit!

As a company says, or used to say, only the best is good enough!

 

7 hours ago, Paul B Technic said:

Great work as always and I love that you also made the B model.

Thank you Paul!

 

5 hours ago, J159753 said:

This looks wonderful, as ever – congratulations!
(Can I raise a side-issue, though? Imgur is no longer available in the UK, and Imgur-hosted images are not visible on UK computers. Please could posters consider using other image services if it's convenient for them to do so? Thanks! https://help.imgur.com/hc/en-us/articles/41592665292443-Imgur-access-in-the-United-Kingdom)

Thank you! You can see the comparisons here.

[Ngoc Nguyen]

Compact outriggers module for those interested. The two 12zgears with frictionless axle pins are added from outside to help with alignments.

[2GodBDGlory]

Nice, that is compact! It's always satisfying to use double-bevel gears in both perpendicular and parallel meshes at the same time

[Timewhatistime]

18 hours ago, Ngoc Nguyen said:

Compact outriggers module for those interested. The two 12zgears with frictionless axle pins are added from outside to help with alignments.

 

Thank you very much for this image. That's the kind we like here!

If you got some more for us, many of us would appreciate it.

Nice usage of the double bevel gears for controlling/pushing out the outriggers in different directions at the same time.

1 hour ago, 2GodBDGlory said:

Nice, that is compact! It's always satisfying to use double-bevel gears in both perpendicular and parallel meshes at the same time

Oh yes, same for me!

[Ngoc Nguyen]

Ultimate achievement unlocked: a Like from Markus Kossman!!! 

[XTN]

9 hours ago, Ngoc Nguyen said:

Ultimate achievement unlocked: a Like from Markus Kossman!!! 

Congratz!

Maybe I'm a little late at the party, but as an enthusiast for everything in MACK scale I was speachless for days by the ingenuity of your MOC.
All the functions in that scale and a B model... If this was an official LEGO set, I'd buy it in a heartbeat.

[Timorzelorzworz]

Wow! Congrats to that on FB. Kossi looks very happy with his Osprey in the title image. I guess this picture was taken before they canceled it.

[Ngoc Nguyen]

4 hours ago, XTN said:

Congratz!

Maybe I'm a little late at the party, but as an enthusiast for everything in MACK scale I was speachless for days by the ingenuity of your MOC.
All the functions in that scale and a B model... If this was an official LEGO set, I'd buy it in a heartbeat.

Thanks for the support! I love MACK scale trucks too. I thought they were gonna be a staple in the Technic lineup, but TLG only did 4 years of that (2018-2021) and dropped it. I also wish something like this was offered as an official set, and the fact that I can make it work means TLG can probably make it work too, but TLG just doesnt do this kind of model anymore..

[Ngoc Nguyen]

Comparison with my previous 8x4 dump truck

 

[Ngoc Nguyen]

On 11/21/2025 at 5:51 AM, Timewhatistime said:

If you got some more for us, many of us would appreciate it.

Here's another design solution I used in the set.

This setup allows compact pendular suspensions in both front axles. To ensure structural integrity, I brace the bottom side with tow ball links that go through the turntables. The links can connect both ends while allows rotation around it because it's thinner than a liftarm.

[2GodBDGlory]

That's a cool solution!

[Ngoc Nguyen]

On 11/25/2025 at 5:22 PM, Ngoc Nguyen said:

I was waiting for someone to point out a drawback of the setup above but haven't seen anything, so Imm spoil it  That setup doesnt really allow a drive axle to pass through to drive the inline 6 engine in the front, and that is an actually challenge I had to solve while designing the model.

The solution is like this. I used a clutch 20z gear to bypass the steering axle. Also in the front, because of limits space, the first crank is only a thin liftarm. You can also notice that I used a bar connector for the last crank because it's directly above the turntable, so it needs to be shorter. A full length 2 module crank will touch the turntable while spinning and can't do a full revolution.

 

[2GodBDGlory]

Oh, very clever! Thanks for sharing these little details