Last friday was a rainy and windy day. I was home, a bit bored and I started to make a bit of sorting in my kid’s bedroom. I gave him my old Legos from the eighties and obviously, like a modern kid, he did not really cared about the instructions, after all, it’s some written paper, who still cares about that nowadays ?! When I got them back to store them in a safer place, his bedroom being a battleground, I remembered when I was myself a kid, when I was building and rebuilding them again and nostalgia started to appear…
Then, I decided to build the forklift but quickly realized that most of the pieces were old and dirty, if not lost and that it could be a bit difficult to complete the model.
So, I went back to modern Legos and started to rebuild the model with studless parts, which is in my humble opinion much more difficult than with old parts. Technically, those classic sets are built from the bottom to the top, like traditionnal legos, which is not the way studless sets are made. They require more thinking, because you always to consider what you will have to build after what you’re currently preparing.
The main difficulty of this moc is that it has a width of 10 studs, which is a even number, whereas studless Legos are made for models of an odd size ! When you were using a studfull liftarm of 16 in the past, you use a studless one of 15 now ! With classic Legos, you can easily place an axle in the center of a 2×4 plate, with studless ones, it becomes a challenge, you can’t even find a 4 studs liftarm, it only exists as a thin one, and with 4 holes, it has no center…
So I made the choice to make the inner chassis, holding the rear steering of an odd size, and to keep the width of the bodywork to 10 studs and it reveals itself to be a good choice, simplifying greatly the creation process. It took me 5 hours to complete that remake, 5 hours of good time, I enjoyed doing it, and I’m quite happy to share the instructions now on the blog !
One of the positive facts you can find when you break one of your bones is that it gives you plenty of time to build some new LEGO models !
Last year, LEGO released the 42043 set, the Mercedes-Benz Arocs 3245. It quickly became the flag ship of the brand, the one everybody was waiting for. In my very humble opinion, that set is totally overrated. Of course it’s well designed, has a nice look and it was, at the release date, the biggest lego technic set ever produced, but the pneumatic functions of the crane were totally unefficient, making the set almost valueless speaking of playability.
The B Model of the set is a smaller version of the Arocs, the 1845 (an Actros ?), it’s composed of a truck and its trailer. Overall, the B model is for me much better, the look remains excellent but the addition of the trailer makes it much better to play with. All the pneumatic stuff was moved to the trailer and used to build a smaller crane, more efficient than the one from the A model. All considered, that B model is a much better build, more fun, integrating almost all the functionnalities of the A model, just better developped and organized.
It’s after watching some Youtube videos than I realized that the B model has such a great mocing potential. The one realized by PPUNG DADDY (From Korea), a full remote controlled version of the truck, inspired me and made me decide to build an advanced version of the 1845, including more functions.
Steering (front axle) : After few hours of work, i decided to borrow PPUNG’s idea and use a servo motor directly fixed on the front axle, it’s not discreet, but very efficient, and I could not figure how to build something smarter. Then, instead of re-inventing the wheel, I followed PPUNG’s instructions and used his steering mechanism, all credits to him for that part (Thanks !)
Driving (rear axle, doubled wheels) : What’s the goal ? It’s a truck whose aim is to move trailers. Does it have to move fast ? Clearly not, or manoeuvres will be extremely complicated, especially when moving backward with a trailer attached. So, I decided to use a simple L motor and to hide it the better I could. I removed the fake motor and placed the L motor at its place, this left me enough space for gearing down and deliver enough torque to the rear axle at a reasonnably speed. The biggest interest of this solution is that the power function motor is totally hidden under the cabin which greatly help to preserve the overall design.
Front lights : The hardest challenge of that improvement was to hide the light emitted by the power function lights on the sides of the truck and on the front part of the front wheels. I decided not to transform the 1845 into a nightclub and to limit myself to the 2 biggest lights of the truck, situated on each sides of the front bumper.
Infra red receivers : 3 motors and one light kit makes 4, so I had to place 2 IR Receivers, and if possible, not far of the battery (that did not moved). Lots of trucks have a radiator for the climatisation behind the cabin, I’ve built one to hide my 2 receivers, It’s not to much ugly and the receivers are well hidden. Small counterpart, you have to be behind the truck to drive it.
5th wheel : The goal of the truck is to move trailers, so the main function, after the ones concerning the movement is the 5th wheel. On the A model, it’s working well, but does not remain locked and may move with vibrations, releasing the trailer. So, I had to fix that and decided to add a pneumatic cylinder. I found a way that suits me well, the cylinder gives a nice look to the 5th wheel, pity LEGO does not make black cylinders…
Tilting cab : This was the biggest challenge of the reworking. The cab is somewhat heavy and requires at least a big pneumatic cylinder to be pushed forward, and even bigger to be moved back to its normal place. Impossible so to use a small cylinder like for the 5th wheel. The problem with the big cylinder is that it requires lots of space. I placed it between the 2 seats but this asked me lots of work to rebuild the cabin around it. Anyway, this is where the fun is, no ? 🙂
Pneumatic pump : Placed just behind the cab, it’s not very discreet, but people usually enjoy watching that kind of mechanism when it is in action (I try to justify my choice !). The motor for the pump is located under the cab too, totally invisible.
Air tank : The use of an air tank really improves the use of the pneumatic functions and makes it more realistic. You don’t have to make the pump work when you want to move the cab or open the 5th wheel and this is really a plus. It replaces the spare wheel on the side of the truck (note : I made 2 PDF instructions files, one with the air tank, and another one without, that part is rare).
I’m quite satisfied of that moc. It asked me lots of reworking time (30+ hours), I had to make several technical choices and find how to add functions without denaturing the original model. Please note that you’ll need almost 100 additional parts to build the truck, none of them are rare (except the air tank). Making the instructions and the computer images took me around 20 hours. I got lots of questions about the softwares I used so I’ll soon make a post about that.
This is the second time I add Power Function motors to the both models A and B of an official set ! When Alpha Mae (see A model) asked me to motorize the 42050 models, I answered her that the B one, the supercharged dragster, had no place for the battery box and would be awful with an enormous box locked to its rear wing, but, after thinking about it, I decided to use a train battery box and to place it just behind the driver’s seat, and to try to see what I could do of that very long and narrow car !
The body of the dragster has enough space to receive a servo motor for the steering, positioned on its side, near the front of the car. Once the steering installed and the previous parts allocated to this task removed, there’s more space behind the driver’s seat, some space that I used for the battery box.
To keep the V8 motor operationnal, I choose to position the driving motor on one of the sides, under the hoses. There’s two sides so adding 2 motors was an idea I got imediately and this greatly improved the torque given to the dragster, giving it a much better acceleration.
Overall this modification of the original model, once finished, is less close than the A modified model was of it’s original model. Several elements of the MOC moved a bit to free some space, some of them even disappeared, like the exhausts on the top of the motor (those made of chain links !), but it’s finally better than expected. Obviously, it’s size does not make it nimble, and the turning radius is terribly wide, but it’s quite fast, and fun to play with !
Hi to all of you Alpha Mae Amor R. Paquibo sent me a mail recently, asking me if I could work on a remote controlled version of the 42050 models. I was a bit away of Lego these last days but this query has motivated me and immediately, having the 42050 assembled somewhere, I took the decision to modify it and add power function motors.
Here comes the instructions for the A model, using a servo motor for steering, and a M motor for propulsion. The result is satisfying and moves fast enough for my taste.
Have fun building it and don’t forget to post me your photos, I will add them to the visitor’s gallery !
One of the limits of that truck is that it’s not a real 4×4 (not a 4×4 at all anyway since only rear wheels are driven !). The Remote Controlled version I built proved that fact, the truck is not able to climb rocks, nor even move when the ground becomes complicated.
At the opposite, the 9398 4×4 Crawler is a true all terrain vehicle, even if his differentials limit a bit its ability to cross certain obstacles, it’s made for the exterior, the mud and the rocks !
Speaking of playability, that set is probably the only one that could be considered as a toy by itself if it was not made of Legos. A 6 years old kid may play with it, making obstacle races or outdoor driving without feeling the limits of playing with a lego car.
It also has a nice look, less accomplished than 42029 though and the choice of the colors is discutable.
Inspired by those two, in february went the idea to build a bigger version of 42029, exploiting the efficient chassis of 9398. In the specifications sheet, from the 9398,I replaced the L motors by XL ones to increase the torque on the 4 wheels and added some headlights in the front. From 42029, I kept the tilting bed but removed the front winch with the idea to reinvent the front of the bodywork and make it more potent.
Building and rebuilding took me at least 3 weeks and lots of modifications but finally led to something which is not always the case for me ! So, here’s my remixed version of the 9398 and 42029 sets, with a few personal additions. Please browse the galery below to discover more of the changes I made to the original models.
As usual, instructions are delivered for free in PDF, feel free to download them and to donate me a few € if you like them or want to contribute to my upcoming builds !