42043 - MB Arocs 3245 Mods and Improvements

[Svart]

Hi all,

I´m building my Arocs now (just rediscovered technic as a great way to enjoy a quiet evening at the kitchen table after seeing The Grand tour compete in building gokarts) and had to try the crane before finishing the rest of the truck.

My question is: The crane moves very slowly. Closing the grabber takes like 10 seconds before it starts to move. Over all there is a lot of waiting, causing me to keep checking if I pulled the lever the wrong way. The further from the pump the worse it gets.
Do you also experience this? Is it possible to add another pump to the same motor and increase the air flow?

Could be a pinched blue hose I guess, I´ll take a look at that.

 

[Imanol BB]

Hi @Svart, welcome to Eurobricks, the Lego pneumatic parts usually do this, as it uses air, it needs a bit of time take enough pressure to operate the various cylinders, and the grabber can even take longer, as there are more hoses thus there is needed much more air to achieve enough pressure, and also because it has an small pneumatic cylinder it can take longer to move, about the solutions, i would recommend you to first build all the pneumatic system separately, just connect the pump, hoses, cylinders and valves together, check that there is no major leaking of air (you should look for any important leakage inside the cylinders and valves, and also check that the hoses have no punctures or leaking), and once you are sure everything is working as it should, build the truck completely, and once you do this check the pneumatic functions again, if everything works fine, and you are sure there is no leaking, you can now work on speeding up the pneumatic pump, a simple gearing up can help you with this, and an small tip i can give you to make the grabber move faster, you can maintain all valves closed and wait for the pump to build up enough pressure inside the system, once this happens you can open the valve for the grabber, this should make it open pretty fast (assuming that there are not additional problems), i hope this works for you, if you need any more help feel free to ask, you can also upload a video showing the problem, so it is easier to understand what else could you need, good luck with your Arocs.

Edited December 11, 2017 by Imanol BB

[Svart]

Thank you Imanol BB!

I´ve tried to let the compressor work ´till it starts to sound differently then close the grabber quickly but it did not help. I did loosen all the moving parts in the grabber a little, that made it somewhat faster (I did not have to begin its movement by pushing it with my finger any more). Opening the grabber is OK fast, closing it takes a while. I was moving olives between two small plates :)
I´ll check for leaks as well.

[Josephiah]

On 21/11/2017 at 2:50 PM, evortigosa said:

The process is a bit complex because involves many steps. I will try to provide a manual soon.

Looks great. Is it possible using only the pieces in the set, or do you need to bring in extra ones?

[Svart]

I solved my crane speed issue last night. The blue hoses were bent to much under the crane close to the switches. Solved it by shortening the blue bits between switches and T-pieces on both sides. I also switched the black and grey for the crane extending bit so "down" on the switch means "longer" (which in reality means Down as the crane rarely points upwards).

Small mods - made a lot for the playability! Speed is now just where I want it and the precision is fine. No problem at all to lower the main arm slowly while loading walnuts from the christmas decorations :)

[agrof]

Glad to hear to have your problem solved! It is trully the most advanced and iconic set from official Technic up-to-date, enjoy it! 

[Ngoc Nguyen]

I've always wanted the trailer in the B model to have proper duallies, but it is only until recently that I have managed to make this happen. So here it is, I would like to present my MOD for duallies in the trailer.

 

Characteristics:

- The axle length needs to be reduced to 11L.

- The tow bars for suspension need to be moved inside.

- Since there is only one hole for the pin that holds the wheel at the end of the live axle, I use the new part Pin Hole with 2 1L axles 180 degree, introduced in 2017. I take them from the spare parts of 42069 after building the B model.

I also put the yellow springs to the second axle because the grey springs bend under the weight of the crane.

Hope this helps.

Edited December 12, 2017 by Ngoc Nguyen

[evortigosa]

On 12/11/2017 at 9:13 PM, Josephiah said:

Looks great. Is it possible using only the pieces in the set, or do you need to bring in extra ones?

Thank you!

Most of the bricks are from the set. 

But some bricks are extra. For example, I changed the four Dark Bluish Gray Technic Liftarm 3 x 5 L-Shape Thick with four Dark Bluish Gray Technic Liftarm 2 x 4 L-Shape Thick and then set the shock absorbers, in the front suspension.

Edited December 19, 2017 by evortigosa

[Marco1213]

On ‎12‎/‎31‎/‎2015 at 3:53 PM, efferman said:

 

 

 

Have you by any chance finished this crane? I have been searching for hours on how to build this and how to attach it with no luck :( (I dearly want this on my aroc.)

EDIT: Nevermind, found the ldd file. Still looking for a way to attach an air tank 

Edited January 8, 2018 by Marco1213

[GlenKirk]

I'm new to the forum, but I have a question. 

I have only done the la steering mod to the 42030. So the 42043 is my second mod.

I am currently building the b model. I have already used effermans ldd file to Creator dual drive tandems for the truck and have the PDF file from livert to make it r/c with the air pump and tank w/ air operated fifth wheel.  I took effermans fenders and extended them to full fenders and incorporated the back bumper and lights into them. 

My question is. Has anybody mod the trailer to a dump trailer with the crane in the front of the trailer? I've seen the extended dump trailer.  

Now I understand that there is alot of inter workings to the crane. That's why I'm asking. Because I'm not sure putting the crane up front can be done without making it to tall or weird looking.

 

I've read all thru this forum and there is alot of beautiful creations by alot of people. Any advice would be greatly appreciated. 

I will get photos of what I have done already tomorrow and try to post them.

 

Thanks.

[dr.gazza]

HI,

anyone know if this model is out of catalog?

[suffocation]

It was discontinued last year.

[Ngoc Nguyen]

A moment of silence for our brothers and sisters who didn't get this set while it was still in production.

Edited August 10, 2018 by Ngoc Nguyen

[TeamThrifty]

Our Lego who art in production, Arocs be thy Name... Amen.

[Maaboo the Witch]

Shame we didn't get a mini version like with the Unimog. 

[TeamThrifty]

Or a whopper with unimog wheels... too much is never enough!

[Bartybum]

A salute for perhaps the greatest Technic set of all time

o7

[Mechbuilds]

Here's a steering solution courtesy of my brother. 

[Arjan de Jong]

Hello, i'am new here. I have made some modifications om my mercedes arocs. I lowered the crane, i changed the front wheels. I made the driving and steering rc- controlled en changed the rear and front of the truck. Hope you like the picrures.

[Arjan de Jong]

Here is a better photo

The other site

[Shakidona]

Hello,

Has any make it full RC and can share or sell instructions?

[Rebel_Lego]

On 5/17/2020 at 3:32 PM, Shakidona said:

Hello,

Has any make it full RC and can share or sell instructions?

A bit late, but search on youtube.com for ‘ppung daddy 42043’ :)

[MiikaH]

First of all sorry for reviving an old topic, hopefully someone still has it for this 7+ years old Truck.

 

This autumn I came out of my grey ages with this Arocs set, as my son started getting to play with the Technic sets while turning three. I myself had a childhood filled with Legos starting from the earliest Technic sets such as my borthers' 8860 Car Chassis (thanks btw for @Blakbird for the superb Technicopedia site), and ending with 8460 Pneumatic Crane Truck and 8480 Space Shuttle just at the dawn of the studless era.

Lately I bought the Arocs used and disassembled. It took me about eight hours of building and many times more tweaking it here and there. 

First thing I noticed was that there was problem with the crane rotation (own topic for that here at Eurobricks also, helped me own the way). During the building process I was very careful routing the pneumatic hoses and tried to route them if possible even more smoothly than in the instructions and cut a little excess off some hoses. Next thing was to change the gearing a little so that the crane moves a little more slowly and gets more torque. And I also modded the backside of the cab a little so that the hoses wouldn’t get stuck anywhere. Since these didn’t really solve the problem, I had to come up with something else. I first added some vegetable oil between the hoses inside the turntable to minimize their friction while the crane turns. After all of this the crane operation was a lot better, but only after I added the same oil carefully to the holes on top of the turntable with cotton swabs the operation became satisfyingly smooth!

The front wheel hubs were modded to resemble more the original, later found out that some of you had come to the same solution earlier. Then I added some sideways stoppers under the front of the tipper bed which I felt had too much sideways motion when lowered.

Next was time for some esthetic mods and improvements. I changed the steering wheel for smaller which imho fits the scale better. The seats I gave a DBG/LBG appearance as it has never been clear to me why Lego is so keen on blue seats. The spoiler above the windshield was modded after finding pictures of similar mods. And as I live in Finland where every truck has extra hi-beam lights on the rooftop I gave the Arocs some too. 

The front fenders being so high and higher than the rear caught my eye, although after googling some images of the real thing I found out that this truly is the case. But in real life, the first axle fenders are even higher so I decided to lower the second axle fenders to the level of the rear, to me it looks better this way. The fenders were built with single colors each and the gap between the doors and the fenders was filled a bit. And as some have mentioned, the Arocs looks a little too hollow under the chassis between the first two axles, so I added some elements there. Also gave the tipper body one stud more height, but not sure still if I like it. A higher front end might be the most realistic.

Then some more mods to functionality. I executed the “sturdier outriggers mod” (presented here at Eurobricks if I remember correctly). The steering radius was annoyingly different to one side than the other, and I spent quite a lot of time fixing that. Then I found some mods to the pneumatics of the crane, with which the beam straightens almost completely from the second joint and the last extension uses the whole range of the slider. That last one is no beauty but I tried to make it as efficient as possible and with the smallest amount of friction. Also played around a bit with the hoses connecting to the grabber so it wouldn’t lean to one side or another. 

I too experimented with softer springs on the front with both axles having the softer springs at the same time and separately. I think they did this already at Lego’s, as I eventually got to the same conclusion as they did. And while working on the front, I added a chain driving the motor. Now the gearing results in a speed of the fake motor that to my eye looks fast enough to resemble a working diesel engine but slow enough for my son to see the actual movement.

Some final steps were adding two fake air tanks to the co-drivers side between the front fenders. And two more wheel chocks on the rear fenders. The last thing for now is changing the blue 2L and 3L pins to black and grey ones, as I’m not a fan of those blue dots everywhere on my build. And the pins weren’t blue as I grew up with Lego 😉

Lastly I added the electric pole reverser for my son, because the switch on the battery box (at least in this individual) moves too easily from one extreme to the other and is very hard to stop to center.

Coming up is pneumatics to open and close the tailgate. Other than that, not sure yet. Of course RC would be nice. And a little less play on the steering. And an air tank. And a trailer. And…

 

Had a hard time with the photos, below is a link to to flickr to find them. Tried my best but couldn't share them correctly by the rules.

Photos

 

- Miika

 

And thanks for a superb forum with great reviews and astonishing MOCs!