KevinMoo

Greetings. It’s been a while.

Oh, I mistook chassis for axles. All those triangles are in system.

I think it’s close enough to be called a “perfect fit”, but the tricky part, for angled beams, is that you have to take backlashes into consideration. That’s why I used some extra parts to compensate for that. The goal is to hold the friction on the cross axle down to its minimum.

In this case, they are not intended to move at all. Both axles are rigid axles, which look like independent suspensions.

Yes, specially designed for this long-wheelbase model

Hey, it’s been a long time. This model is actually finished at the end of last year, I finally got time to make some improvements and show it to you. Ever since the introduction of the new planetary wheel hub, I’ve been trying to find ways to use it on medium-size/small-size models. With fixed ball joints, steering arm seems to be the only choice no matter what kind of axle you would like to build. While experimenting a parallelogram structure, I found something interesting: When you setup a parallelogram like this, two yellow liftarms are perfectly aligned with a one-stud offset. So it could be used like this: In this way, a narrow solid axle could have some extra ground clearance. This is all theory. In practice, as you can imagine, backlashes will cause frictions between cross axles and 5 x 11 frame. So I have to add some extra parts to help keep steering arms steady. In fact, both front and rear axles were “overly compensated”, which means when you hold the model in your hand, the pressure generated by these extra parts is more than sufficient to keep the steering arms from moving even a tiny bit, when the model stands on its own, the extra pressure and the gravity balance out. I don’t have a way to measure exactly how much the friction is between the cross axle and the 5 x 11 frame, nor do I know if it’s less than or more than a conventional solid axle. At least from my test, the wheel’s rotation is just as smooth as I want it to be. That’s about the main feature of this creations. Hope you like it. Building instructions: https://rebrickable.com/mocs/MOC-47249/KevinMoo/toyota-land-cruiser-76/

All those rendered parts in the parts list on each page are generated by LPub3D, when opening a MOC file in LPub3D, you can find all individual parts under the “LPub3D”-“assem” folder. All the rest are just Photoshop work, including frames, arrows, texts, chroma keying, etc.

hey guys, I have completed building instructions for the Monster Truck: Besides the change of color scheme and other minor improvements, I’m using a new full-frame camera to shoot all photos for a better picture quality. It’s now available for free on Rebrickable: https://rebrickable.com/mocs/MOC-26278/KevinMoo/monster-truck-with-automated-differential-lock/ Hope you like it and enjoy building!

@LegoTT I can really appreciate that, and this is definitely not personal, especially not against you. I was just trying to stop a trend in this topic, and you don’t need to apologize. Thanks for sharing your experience.

This seems to be a legit auto diff lock, but I don’t know the existence of it until now. If you ask me “Is this your original idea”, yes it is, but I will never know if I’m the first one to have such an idea. Again, to me it doesn’t matter who did it first. I never claimed to be the first to do anything, and I don’t want it either. If someone just want to claim “1st prize”, fine, just take it. But it’s meaningless to discuss topics like “the first one to do something” in my opinion, So please, stop posting time marks.

Hey Gerard, Firstly, it doesn’t matter who came up with an idea in the first place, to me it’s not important at all. secondly, I don’t believe you have read this topic or watched my video thoroughly, but I have studied your video well enough to believe that our models have completely different structures, serving completely different purposes. What I have designed is a differential LOCK that locks when the vehicle is driving straight to achieve maximum off-roading performance, and automatically unlocks when it takes a turn for better maneuverability. In your video, I don’t see an actual lock.

There is one thing which has a great influence on off-roading performance, that is differential. Open diffs will severely cripple off-roading capability of a vehicle, but without a diff, turing radius is going to be awful. Can you really balance the two? I’m showing you two new MOCs regarding this topic: a Land Rover Defender & a monster truck. (There will be two new official LEGO sets which happens to be a Defender and a monster truck, I think this is pure coincidence...) 1. Land Rover Defender I have never tried building a model with no differentials. So maybe I should give it a try to see how it performs. The drivetrain is pretty straight forward: Then I started adding details to it. I was expecting it to be a lightweight model, but when it seems aesthetically acceptable to me, the final weight (1.3kg) is beyond my expectation (around 1kg). Other than that, the actual turing radius is really bad, something I can’t take. So Let’s not talk about performance, just take a look at some details: I have to say this MOC is not too sucessful, so I didn’t bother making a video for it. Even it is fully remote-controlled, to me it is still a display set. 2. Monster Truck So how can we really get maximum performance without losing the benefit of differential while cornering? Most of us know the answer: diff lock. We’ve seen so many great builds with manually or remotely controlled diff locks, and I want to make something different. Then I came up with an idea: Can I design an automatic diff lock, which locks when the vehicle goes in a straight line, and unlocks when it takes a turn? Of course in many cases the vehicle also needs that diff lock to be locked when it takes a turn, but considering it’s a fully automatic action without an extra motor to control the lock, This is an acceptable trade-off. Besides, other factors could somehow compensate for that, like grippy tires, responsive suspensions, etc. I soon realized that this is not going to be a tough job. I only need a simple mechanism that somehow links the diff lock to the steering motor (Servo motor). A video (4K) to show it all: The concept of this MOC came from Monster Jam trucks, that’s why it has roll cage and detachable body. The chassis and axles is no way near a real monster truck, it is built solely for the purpose of demonstrating the auto diff lock. And I think it performs great and seems reliable enough. Hope you like these two MOCs!

Hey guys, I have completed the MOD. My goal is to rebuild a better seat, so I have to find out a way to reposition the propulsion motors to make room for the new seats. This is the original model: First idea came to my mind is to rotate the motor 90 degrees so it could be lowered 1 stud, and let the seat sit on the flat side of it. It came out like this: It’s definitely a better solution, but the seat still looks small and not quite authentic. So I decided to push it to the extreme: move the motors forward, then put the gears behind the seats, and make the driveshafts pass through the seats. It turns out to be feasible: Now this could be called a significant improvement. Though the ideal location for the seat should be 1 stud downwards and 1 stud backwards, this is the best I can do. The improvement comes with a trade. There is a speed loss due to gear change. But this is as far as I am willing to spend more time on it. It’s a tough job to balance aesthetics and functionalities for a motorized supercar at this scale. I think it well deserves the name “Challenger”. Hope you like the change!

Guys, thanks for your comments and advices. I’m working on a major improvement of the interior, including the drivetrain and the seats. I rarely do further optimization for a published MOC, but this one shows a great potential to be a better MOC. So stay tuned!

EDIT: Improved Interior -------- I’m a big fan of medium-size models. Ever since the first appearance of the curved panel (part 18944), I’ve been planning to make something out of it. And it couldn’t be more suitable than putting it on a supercar. Finally, presenting my first ever supercar - the Challenger. This MOC is equipped with 56 x 28 tires, making it a roughly 1:11.5 scale model. It’s really challenging to design a bodywork with complex curves for a supercar at this scale, hence the name Challenger. BODYWORK Normally wheel arch made of liftarms has flexible axles inside, but I choose to use rigid hose because it’s slightly better than soft axle in terms of keeping shape when the desired curve is short and subtle. Together with the curved panel, they create a beautiful silhouette. Even though this MOC looks like a Porsche, and indeed it is mainly based on Porsche design, but it is not a Porsche. Especially when you look at the rear end, it’s definitely not a typical Porsche style. Actually the whole bodywork referenced several car brands, it’s more of a combination of all my favorite parts from different design styles along with some of my own thoughts. DRIVETRAIN & SUSPENSIONS It is powered by 2 L motors, and steered by servo motor. Front suspension is a conventional independent suspension; rear suspension is a multi-link suspension which incorporates what is called a Watt’s link. It works just like a Panhard rod, but slightly different from Panhard rod. PERFORMANCE COMPROMISES & IMPERFECTIONS Due to limitation of the size, I really couldn’t put everything I want into this MOC. One big problem is the seat. Since the motors take too much interior space, the seats have to sit high on the motors, while in a real car they are much closer to the floor. And they don’t look like racing seats. Secondly the rear suspension is really stiff and suspension travel is short, so it couldn’t take full advantage of the Watt’s link. Also the absence of working headlights and taillights and the noncontinuous curve of this liftarm-made wheel arch are the compromises I have to make. Anyway, I’m basically satisfied with this MOC, it’s a good start of creating motorized medium-size supercar for me. Hope you guys like it And happy Chinese New Year!