Icekusbe's MOC yard

[icekusbe]

Hello,
I decided to create one topic for posting some of my MOC:s, such as trucks, tractors and military vehicles. Let's start with my latest creation:
Toyota Hilux Double Cab

This was perhaps the most detailed creation I have ever done. RC 4x4, independent front suspension, leaf spring rear suspension (soft axles + shock absorbers), lockable central and rear differentials, and a 4-speed gearbox (manually controlled). A minus is that there was no space for rear diff lock controls, so it has to be clicked on from the below. I detailed the outdoors looks pretty far, but the indoors dont look so good.

[icekusbe]

Next, some tractors:

MTZ Belarus 1221.1

This one was fun to do. 4WD, swinging portal front axle (but no differentials :( ) and old 8880 rims mounted on large turntables.

 

Front-end loader (based loosely on Valtra N163)

This one had more playability. 4WD with swinging front axle too, remote-controlled loader height (but the other function is manual), lockable rear differential, DIY planetary hubs in the rear with 4:1 reduction, and a constant-difference central differential for linear gear reduction between front and rear axles. I also built this openable container and 1-actuator hooklift to spice the logistics games up a little.

Sorry for using these sawn-off ball joint beams; I have a pile of them so ruining two of them for a narrow tractor front axle won't hurt.

[icekusbe]

Continuing with the tractor theme:

Unbranded 4WD tractor

I wanted to build an RC tractor moc with the 94.8mm balloon tires in front so that I could use the 56mm Defender rims for the steered axle. I ended up in this design where the steering servo is fixed to the tractor body, moving a 1x7 gear rack that is attached on a link to the pendular front axle.
For the front and rear tire to have almost matching peripheral speeds, I used a 28:24 gear ratio between the axles. Here is the result:

Please guide me to other tractor MOCs with 94.8/107mm tire scale if there are any; I'm interested in what tractors people have scale modelled with these tires.

[Paul B Technic]

Nice work. I feel the wheel base is a little short, given the size of the wheels.

[icekusbe]

On 5/5/2024 at 12:37 PM, Paul B Technic said:

Nice work. I feel the wheel base is a little short, given the size of the wheels.

Thank you for your kind feedback; a longer wheelbase could also allow better offroad capabilities as the centre of mass could be more further to the front as the hub takes so much space. Perhaps I'll create a revision of this tractor design in the future following the design of some existing tractor.

It's been over a month now since my latest post, as I've been quite busy and stressed over writing my master's thesis in engineering. However, here's a small and rather unoriginal build I've managed to build every now and then:
Mercedes-Benz Zetros 6x6

Building this truck began during my latest impulse buying session in BrickLink. I've wanted to build narrow axles with diff locks and planetary hubs for a long time, so I bought a bunch of these red 2L driving rings and took them on a date with Mr. Power Drill to expand the hole from the other end so that the rings could lock with heavy duty diffs.Building these axles is possible using the 2473 gray 2L driving ring introduced in Yamaha MT10, but these weren't available at BL in sufficient quantities by the time I started building this.
I then built the chassis and leaf spring suspension around the axles, and finally the cockpit using as much of the Lego Zetros design as possible.

Sadly, the diff locks do not have a centralized toggling mechanism, as the front axle (with steering motor attached) does not have space for attaching the gear shifter lever on the top and operating it via an u-joint. I should overcome this issue later and create some other truck with diff locks on all axles.

For my next build, I have three different ideas:

• Tatra Phoenix 10x10
• Unimog trial truck with 107mm tires and my close-pivot point portal hub design
• SCARA robot

[jorgeopesi]

Huge truck I love it.

[Paul B Technic]

I love the look of that truck, well done.

[icekusbe]

Hello, thank you both for your kind comments.
It's been a while since my last post. I've not managed to finish many MOC projects, but here's a few of my recent builds/WIPs, yet again continuing in the theme of huge trucks, tractors and offroad cars.

Volvo Defence FMX 6x6 Rigid with hooklift (3x C+ motors)
I've always had a soft spot in my heart for hooklift trucks. They're however hard to implement in Lego builds with live axle suspension, as the hooklift mechanism easily makes the rear of the truck too high. In this solution, there is no axle with a wormgear attached in the hooklift's boom arm, but rather a wormgear in the body that allows moving the container back and forth in the loaded position. This of course brings the downside of now being able to use the hooklift in dumping move without having the container slide back.
The 6x6 chassis itself is quite simple; one C+ motor controlled in servo mode is attached to the steering axle, and the two rear axles are attached into a simple "leaf-spring" system (i.e. a beam with tow ball sockets in each end).
This is my most recent build, and in the stage of "late WIP"; I've not yet built details to the interior, bumpers or lights, and this is waiting for a C+ hub from another build.

More images available behind this link, including a picture of the bottom: https://bricksafe.com/pages/icekusbe/volvo-defence-fmx-6x6-rigid-w-hooklift


Massey Ferguson 275 4WD (2x C+ motors)
Every now and then I love to build a MOC of a 4WD tractor merely due to the challenge: how to fit in the bulky C+ hub, how to steer the swinging front axle, and how to build the gear reductions for spinning the different-sized front and rear wheels in matching radial velocities without a central differential, all whilst trying to fit the features in a small-enough scale for Lego's largest non-motorbike tires (107mm). This time I wanted to make it red for the challenge, as I only had a few red parts in my arsenal.
I don't enjoy using the 81mm tractor tires so much, so I replaced the front tires with the Audi tires. The 81mm tractor tires feel so bulky due to their width.
I still have this model intact, so I could take additional pictures from some part of the model if there's interest.


MAN KAT1 8x8 (failed build :c)

One challenge I've tried to overcome in several MOC projects is a system for two steered & driven live axles. I like the asymmetrical design in the bodywork of MAN military trucks, so I wanted to build a chassis with that one.
My ambition with this project quickly became a nuisance, as I didn't settle for 4x4 or 6x6, but wanted to build this truck as 8x8. Finally, the steering axle configuration worked, but it turned out that the chassis had a weak point somewhere near the 2nd axle, and the entire truck didn't stay intact. Instead of disassembling it and building a stronger chassis, I decided to give up with this project. Also, I learned that using a rack-and-pinion steering for the second steered axle with a different gear reduction than in the first axle does not work in practice quite well, as it's nearly impossible to align the wheel angles of the two axles, plus it makes the second axle bulky in the vertical direction. I'll have to figure out some system using links and towballs for steering the second axle.

I grayed out one part of the MOC that I didn't like too much. That part was my failed attempt in building a mechanism on top of the truck, which didn't work out quite well.


Miscellaneous suspension prototypes
Almost always I start my build from the front axis, as it's the most packed area of AWD RC models. I like to experiment with different front axis setups, and perhaps build a vehicle around it later.
The first picture is a chassis for double wishbone suspension with DIY portal axles, including also differential locks. This could be used in a larger Humvee or RG32 build. As you can see, the upper wishbone arm is almost horizontal, while the lower wishbone points a little downwards. Due to this, the tire stays in good contact with the road when that side of the suspension is pressed down.
The second picture is from my search for a good suspension geometry for front wheel drive: a little camber and maximal contact surface area with the road in curves. I might build a rally car MOC with this setup some day.

 

[icekusbe]

T-55 tank

I built this one about a month ago. If I had the inspiration a little later, I would have built this to the TC29 contest for tracked vehicles :)
I wanted to build some tank that Finland has used in some point of history. While looking for a nice tank model to build, I ran into the following problems: 1) tracks in most historical tanks are very narrow, meaning that a scale model should be excessively wide and long to have the tracks in correct scale, and 2) modern western tanks are very long compared to the width, meaning that the model's hull would be over 60 studs long. I then picked T-55, because it has quite wide tracks and it's relatively short.

There's a PU hub behind the front armor. One of the armor plates can be detached to put the hub on. There's 4 PU L motors: three in the hull to drive the wheels and the turret rotation, and one in the turret to adjust the cannon vertically.
I wanted to share this, because the suspension might give inspiration to some TC29 contestant. It's a very simple torsion bar suspension that takes space mostly horizontally, but fits under the tank without requiring much vertical space. I also made use of 43mm rims as the road wheels, but I have to warn you: the tracks do not run very smoothly on these wheels!
I am quite proud of how the turret turned out with only Technic bricks (except the circular plate with 4 studs). Now I can take this build apart and start building something different for TC29 :)

[Paul B Technic]

That tank is very cool.