A memorial to Mr Fluffy the hamster, who used to occasionally appear at the photo-sessions of my models.

Just as much as I love building with bricks, I love animals too. Especially the small, furry ones with tiny pink feet and sniffing nose. Therefore with Mister Fluffy it was the love at first sight.

Mister Fluffy, sometimes called Sir Meatball or His Obesity because of his shapely silhouette and stately manners, was an exceptional dwarf hamster. He was friendly,  trusting and patient, and above all else he loved food. It was never needed to tame him, because instead of running away from human hand he would rather look for some food in it. He could eat almost anything, including Lego tires which he attempted to nibble at whenever he had a chance. Over time, he grew confident enough to occasionally pull a sandwich off my very own plate when I let him roam the table during breakfast. On one occasion he has climbed up a sugar bowl and filled his pouches with pure sugar. Living in a kitchen, he would always wake up at the sound of the fridge being opened, and when I came back from shopping, he would demand to be let out of his cage in order to inspect the purchases.

His bricks-related career started in August 2008, when he was bribed to appear as a test load for my scissor lift. Both his photo-session and video have been well received, and thus he became my regular assistant, although he did not appear frequently because I felt that his charm should be used sparingly.

Over the span of a single year he appeared with 6 of my constructions. With time, he even played a role in short stories with dialogues, but his last role in August 2009 was again a test load, so he sort of came back to where he started. You can see all the 6 constructions and videos here.

On September 23rd 2009 he fell asleep for the last time, never to wake up again. He was nearly 2 years old, and remained healthy and lively until the last day. He passed away the same way he lived – peacefully. Perhaps he was dreaming of some really tasty snack, and certainly he is free of hunger now. I will remember him this way: happy, feeling cosily in my hands and caring only about his piece of chocolate.

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Model of the world’s largest wheeled front loader. Features 4×4 drive, realistic suspension, lights and arm & bucket controlled remotely with linear actuators.

Datasheet:

Completion date: 30/08/2009
Power: electric (Power Functions)
Dimensions:  length 58 studs / width 22 studs / height 23 studs
Weight: 1.57 kg
Suspension:  front – none / rear – pendular stabilized with shock absorbers
Motors: 1x 71427, 2x PF Medium, 1x PF XL

Articulated 4×4 vehicles seem to be my soft spot. So far I’ve built three front loaders and an articulated bulldozer, only to find out that I still have a reason to build another front loader – that is, I’ve never used linear actuators with a front loader until now.

The machine I’ve picked this time is the world’s largest wheeled front loader. Le Tourneau L-2350 (sounds French, but it’s actually USA-produced) was designed to co-operate with the largest mining dump trucks (such as e.g. Liebherr T282B whose model I’ve built some time earlier), and at a gross weight over 250 tonnes it is able to move 75 tonnes of load at a time. I was initially attracted by its immense size, hoping that it would allow me to build a large model with plenty of room for internal mechanics. It did not.

As usual, the model’s size was limited by the wheels. The original L-2350 is a huge machine, but unfortunately its wheels are huge too. With Lego 94mm wheels being the largest wheels available for this model I was forced to build it just 22 studs wide. 22 studs may seem like a lot, but only until you look closely at how a regular front loader is usually built: the bucket is 22 studs wide, while the vehicle with wheels is 20 studs wide. The hull without wheels is only 14 studs wide. It still sounds like a lot of place, but almost half of it is made with various small side bulges. The central part of the hull is merely 8 studs wide, and this is where the entire mechanics has to be placed.

The model is really compact – to the point where it would be impossible to build it without the 8878 battery – the standard PF battery box is way too large. It’s driven by a PF XL motor housed in the lower rear part of the hull. The rear axle consists of my usual 3-studs wide differential bracing, which serves as a pendular suspension stabilized by 4 shock absorbers (2 at each side). At the same time it transfers the drive further, through an universal joint, to the front axle which consists of the same, but fixed, bracing. The drive motor is also connected to a large fan that can be seen through a grill plate at the back of the vehicle. Front loaders usually have large radiators in the back, and I liked the idea of placing there a big fan that rotates as the vehicle drives.

The steering mechanism in such a model is always tricky because of the size limitations and a substantial gear reduction necessary. It’s impossible to use turntables in a model that small, and I found even the liftarms to be too large for the central joint structure. The structure was compacted as much as possible and is held together almost exclusively by a single vertical axle. The steering is achieved by a horizontal 40-teeth gear placed on this axle, which is driven by a PF Medium motor through a worm gear. The central joint is traversed by two universal joints – one driving the front axle, the other driving the arm elevation mechanism – and three wires, two of which power the front lights while the third one powers a 71427 motor located above the front axle.

Since it was literally impossible to house all the four motors inside the rear half of the vehicle (I was barely able to fit two IR receivers in there), I was forced to place one motor inside its front half. The motor had to be as short as possible, so the 71427 motor was an obvious choice – it’s two studs shorter that a PF Medium motor while providing similar speed (and much lower torque, but it was not needed for its function). Thus, the bucket is tilted by the 71427 motor via a safety clutch, and the arm is raised by a PF Medium motor housed in the rear part of the model.

The use of linear actuators was the very reason this model was built for, and it proved a significant advantage. Not only the linear actuators are far more accurate and stronger than pneumatic cylinders, but they also make the central joint free of any troublesome pneumatic hoses. There are three actuators used, only one operating the bucket – the real machine uses two hydraulic cylinders for that purpose, but the available space was simply too narrow for two actuators.

As for the look of the model, it suffers from a number of compromises for the sake of functionality – the most apparent of which is the battery box protruding upwards from the rear part of the hull. On the other hand I find the wheels quite neat. I couldn’t find any Lego wheels that would look like the real ones, so with a bit of inspiration from a fellow LUGPol builder M_longer, I’ve used black 94mm wheels with black tires and yellow sprocket wheels placed inside.

I consider it to be an average model. I must admit it performed somewhat better that I expected, but I still had the feeling that it could be much better if only I could make it a little bigger. It was also my first model with a high quality video – I made an effort of filming and rendering it in a quality that would comply with the YouTube HQ standard just to see what it would look like. I was pleased with the effect and decided to make all my future videos in that standard.

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Model of the Kenworth W900 in a version customized by the Mammoet company. Features full pendular suspension, functional steering wheel, R4 piston engine, openable bonnet, sleeper’s roof and doors, remotely controlled front and rear lights, automated reverse lights and trafficators, remotely locked catch and custom stickers. My first construction powered by the Lego 8878 rechargeable battery.

Datasheet:

Completion date: 29/06/2009
Power: electric (Power Functions)
Dimensions:  truck – length 75 studs / width 19 studs / height 26 studs, trailer - length 111 studs / width 18 studs / height 12 studs
Weight: truck – 2.66 kg, trailer – 0.709 kg
Suspension:  truck – full pendular, trailer – none
Motors: 2 x 71427, 1 x PF Medium, 2 x PF XL

Kenworth W900 is one of the most iconic US-type trucks, and the Mammoet is one of the most impressive companies ever, handling stuff like transportation of bridges or houses on a daily basis. Moreover, it is a Dutch company, just like the Lego, and it uses almost entirely black livery for its vehicles which is very appealing for me. Finally, the Mammoet fleet, which consists of some of the world’s biggest and most powerful vehicles in their class, contains a number of customized vehicles, which makes them even more interesting.

There is one obvious point of reference for this model, that is my Tow Truck, completed almost a year earlier. I have assumed that it would be difficult to exceed its level of technical complexity, and if I tried to, it would most likely result in a vehicle of even bigger size and similiar look. That is why Kenworth was meant to be simplier and built with more focus on its aesthetic side.

First thing about the aesthetics are somewhat missed proportions – although according to Mammoet’s blueprints only the bonnet is 2 studs too long, and the rest of dimensions is more or less correct. Nevertheless, the truck looks long and narrow. I have recreated Mammoet’s livery on the body, but not on the bumpers, preferring to keep them free from paint job. Instead, they were fitted with small warning badges, and on the front bumper has a set of guards that Mammoet company uses in trucks intended to push some loads. There are no warning lights, either. I’ve put a lot of work into the bonnet, which can be opened up together with the front mudguards, which is a realistic solution unlike the one used in my earlier Tow Truck. The sleeper was made taller to fit the mechanics in, the catch was increased in size to achieve more accurate shape, and rear mudguards were added.

The model was designed for use with a standard Power Functions battery box, and only in the last stage of building it received the Lego 8878 rechargeable battery instead. The battery decreased sleeper’s height and truck’s weight (by considerable 160 grams) while not impacting the performance in any apparent way.

The suspension system consisted of three simple pendular modules, with axles #2 and #3 using my 3-studs wide differential bracings, each stabilized by four hardest 6.5L shock absorbers available to handle the truck’s weight and load. The front axle had no shock absorbers at all, because too much place was taken by the bonnet and front mudguards. Since the entire suspension is pendular, the truck is susceptible to a transverse tilt resulting from the driveshaft’s load, but it is greatly limited by the hard shock absorbers.

The model is driven by two PF XL motors facing each other and connected by four bevel gears. I have tested this setup before, and I liked how simple and effective it was. Additionally, the use of two motors facing each other substantially reduces the strain on the drivetrain. When I tested it with a single motor, it had a tendency to pull the driveshaft down or up if it was not reinforced properly. With two motors, the driveshaft remains in place because while one motor pulls it up, the other pulls it down. One of the four bevel gears is an idler gear, used only to keep the other three gears in place. It can be easily noticed that the motors would look better if they were located along the body – they would then look just like the fuel tanks. It’s a nice solution, but it makes the vehicle’s frame and transmission much more complex, and so I gave it up. I have to mention that the truck turns surprisingly smoothly, most likely thanks to the long span between the steered axle and the driven axles. And it feels very pleasant and realistic to drive it with the speed control-enabled 8879 handset.

It may come as a surprise, but there is no gearbox whatsoever. I’ve done a lot of tests with a linear 3-speed manual gearbox, which seemed most adequate due to it size and robustness, but it proved somewhat loose and the model performed much better with no gearbox. I intended to use the speed control feature anyway, so the gearbox was eventually removed.

The catch lock mechanism is very simple and compact. It uses a worm gear to hold the trailer in place, and a linear clutch to avoid damage. It was located just above the last axle, which is why I’ve used a custom casing (the standard Lego casing wouldn’t fit in), and it was driven by a motor located in the chassis, directly in front of the second axle.

Slightly in front of the second axle, there is also the steering system’s power output, intended to be connected to the trailer’s own steering system to couple it with the truck’s steering. I have tested a trailer with such a system, but I eventually faced the choice whether to make the trailer with steered axles or to make the trailer which is strong and looks realistic. I have chosen the latter.

Between the fuel tanks, there is a reverse lights activator in the chassis. It consists of a single PF switch whose movement is limited to a neutral and one extreme position , and which is connected to the driveshaft through a clutch. The reverse lights are powered from the same output as the drive engine, thanks to which they go out as the truck stops.

The doors of the cab can be fully opened after removal of their side bars. Inside the cab, there is a functional steering wheel and a simple cockpit. There are no seats, because the respective space is occupied by the trafficators mechanism. I will now explain how it works. Imagine a PF light powered through a PF switch – it blinks as the switch’s position changes. Such a motion can be easily motorized by means of an eccentric mechanism – that kind of solution was already used in the forementioned Tow Truck, and can be well seen in my Snowgroomer. Now, imagine a ratchet that is sensitive to the direction of rotation – it has been used in my direction sensitive gearbox. We can attach the motor to the ratchet, and then prepare two separate eccentric mechanisms with two separate PF switches and two separate set of lights (of any size – in fact, I would make the rear trafficators work too if I had 9 lights instead of just 7). It will result in a mechanism when only one eccentric mechanism is driven at a time, and it changes as the direction of rotation of the steering motor changes. Thus, it is perfectly possible to use the steering motor for it, as it can easily control one more mechanism, and I have used a separate motor here only to be able to locate the trafficators mechanism independently of the steering motor’s location. The trafficators’ lights are powered from the same output as the steering motor, so they go out when it stops working, regardless of the wheels’ position.

One drawback of this solution is that the eccentric mechanism remains in whatever position it was when the ratched moved to the other one. It means that there is a high risk of having all trafficators come up at the same time, because the ones that should be off will have the PF switch stopped in ‘on’ position. It can be prevented with rubber bands that pull the eccentric mechanisms to a specific position once they no longer mesh with the ratchet, but I did not use such means of prevention because of the available space limitations. Please note that the truck already houses approximately 5 meters of electric wire.

Under the bonnet, there is a R4 piston engine with moving pistons and rotating front fan. It is small because of the limited space under the bonnet which results from its specific construction. As you can see on the photo below, there is an interesting area near the front axle where the model’s smooth external surface ends and a Technic structure can be seen beneath it.

Finally, the trailer. I wanted it to wear a different colour scheme. Trailers of this type usually have red and white warning stripes on the edges of main platform. I didn’t have the needed number of red and white parts, and I disliked the look of these colours combined so I replaced them with two shades of grey. The trailer has no steering system nor suspension of any kind, and it is attached to the truck in a fairly simply way. I have to admit that the truck took a terrible amount of work to build and I really didn’t like the idea of even more work with the trailer, especially since it was difficult to show or film together with the truck due to its length. Therefore the trailer is an addition to the truck rather than a proper model.

Overall, the model enjoyed a fairly good reception, despite many people pointing the proportions issue out. The trafficators feature was widely acclaimed, and there was even a number of people who were very critical about the proportions and accuracy of the truck, but still regarded it as an impressive model. Few people declared that the focus on the truck’s aesthetic aspect was much greater than expected of me, and that its functionality was degraded because of this.

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Media reference:

Bricks ‘n’ Gears, kockak.hu, TechnicBRICKs

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Model of one of the largest Liebherr excavators. Features 6 motors with full remote control, chassis driven from the superstructure and infinite freedom of superstructure rotation.

Datasheet:

Completion date: 12/02/2009
Power: electric (Power Functions)
Dimensions:  length 47 studs / width 18 studs / height 27 studs (with arm in transport position)
Weight: 1.52 kg
Suspension: none
Motors: 4 x PF Medium, 2 x  71427

My goal here was to create a fully remote controlled, pneumaticless model of an existing excavator, while keeping it reasonably small. My long-time affection made me to turn to Liebherr excavators, and I have chosen the R996 Litronic model with the undershot arm, due to its hull’s shape and arm’s construction. It was scaled to the size of the 3-studs wide tracks, which also suited the size of the linear actuators quite well.

The priority was to reconcile a realistic drivetrain with an enclosed hull construction. In real excavators the chassis is basically driven by one or many motors located inside the superstructure, thus ensuring the infinite freedom of superstructure rotation. This is possible thanks to a hydraulic system, which can’t be modeled with currently available Lego parts. Therefore, it can be only solved by pneumatic or mechanical means, the latter solution being much more compact and reliable. An iconic example of the mechanical solution is the model of a JCB JS220 excavator by Jennifer Clark. The essential trick is to transmit the drive through the turntable by a vertical axle with a free rotating driving ring on it. The driving ring can be assisted by an extension driving ring to transfer the drive further vertically, and eventually is meshed with the t16 gears used in the gearboxes. Thus we have the vertical axle transmitting drive to one track and the driving ring transmitting drive to the other track independently.

The functioning of this solution is slightly affected by the superstructure’s rotation, as the position of motors in relation to the tracks changes. Usually it results in the tracks being slowly driven by the supestructure’s movement, but this effect can be greatly reduced by the gear reduction below the superstructure. Here, however, the use of 71427 motors plus the gear reduction and the model’s weight resulted in motors being driven by the rotation rather than the tracks. Still, the drivetrain worked flawlessly, which can be clearly seen on the video when the superstructure is rotated clockwise while the chassis turns in place counterclockwise.

The hull’s construction was challenging from the very beginning. About half of its internal space is occupied by a battery box, and additional space is required by the IR receivers along with the wires. This leaves just about 40% or less of the internal space to be taken by the motors. I initially hoped to contain 4 motors inside the hull, but eventually only three fit in. The other three were incorporated directly into the arm, which helped to counterbalance the weight of the battery box and simplified the transmission system inside the arm.

I’ve spent a lot of time working on the geometry of the arm, and in the end it’s range of movement is as close to the real one as possible, while the number and the location of the linear actuators is almost identical to the number and location of the real machine’s hydraulic cylinders. The model turned out to work quite efficiently, it had a good weight distribution (although it could use a little more weight in the rear part), passed all practical tests, and was able to easily support itself on the arm in order to e.g. lift the front part of tracks above the ground. I was satisfied with its performance and considered it one of my most compact constructions ever.

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Media reference:

DoubleBrick

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Model of a classic Morgan 4-4. Features full suspension, remote drive & steering, functional steering wheel, lights, manually opened doors and manually adjusted seats.

Datasheet:

Completion date: 03/01/2009
Power: electric (Power Functions)
Dimensions:  length 48 studs / width 17 studs / height 16 studs
Weight:  1.39 kg
Suspension:  front – pendular without shock absorbers/ rear –  independent
Motors: 1 x PF Medium, 1 x PF XL

From time to time I am accused of ignoring aesthetics for the sake of functionality. These accusations are still present, even though the influence of LUGPol users made me pay much more attention to aesthetics than I used to do earlier. With this model, I wanted to answer this kind of accusations, and to prove that I can build a good-looking medium size car model, despite the failure the Cobra model was.

The front part of the car was the biggest challenge. I have developed my mini pendular steered suspension module specifically for this model, and managed to contain it under the narrow, low bonnet. The steering lock was greatly limited by the mudguards. Steering was controlled by a PF Medium motor with a safety clutch, thanks to which it was possible to use driver’s steering wheel instead. The drivetrain was very simple, and consisted of a PF XL motor driving the 3-studs wide differential. There was no rear axle, however, and instead the rear wheels were suspended on dragged longitudinal rocking levers. This solution provided better stability than a pendular suspension could provide (no torque effect), as well as more internal space for the battery box behind rear wheels. The only drawback was the robustness and stiffness of the rear suspension, which were worse than in case of a pendular one. The PF XL motor was located under the seats, and the IR receiver was put between them.

The look of the model was fairly accurate, with a number of minor concessions to the functionality. Namely, the front mudguards were not fully covered, but had holes behind the headlights, to preserve internal space for the front wheels’ movement, the tresholds on the sides of the car were taller than they should be, in order to contain all wires inside the chassis, and there was an opening atop the rear part of the body, which provided access to the battery box switch. Given the size of the model, I consider these concessions acceptable.

The model was well received, partially thanks to the mr Fluffy’s great work on modeling. Some of the people following my work called it a rehabilitation after the Cobra failure. Additionally, it was my first construction published at LUGPol outside the Technic section – I’ve chosen the Model Team section instead.

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Media reference:

Klocki

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Concept of a chopper built out of several interchangeable modules. Features full suspension and V2 piston engine.

Datasheet:

Completion date: 19/10/2008
Power: none
Dimensions:  various
Weight: various
Suspension:  full independent with shock absorbers
Motors: none

Some time ago, I’ve watched the entire process of building a custom chopper from a scratch. I thought it could be mimicked with Lego brick, through a modular system where one universal frame can have a number of compliant modules attached to it. I’ve designed such a system, trying to keep it close to the original one, and in result it consisted of a frame, front and rear wheels, front suspensions, handlebars, engines, seats, exhausts, fuel tanks, rear suspensions and rear fenders. Though I’ve only built few modules of each type, it offered a substantial number of possible combinations, out of which I’ve only assembled five. Each version featured full independent suspension and a V2 piston engine driven by the rear wheel through a chain and a rubber band. Once more, mister Fluffy has been kind enough to honour me with his model’s skills. It is accurate to say that we did a nude session with one of the chopper’s versions

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Manually controlled scissor lift, using a single linear actuator.

Datasheet:

Completion date: 06/08/2008
Power: manual
Dimensions:  length 18 studs / width 9 studs / height 17 studs (fully lowered) or 38 studs (fully elevated)
Weight: 0.22 kg
Suspension: none
Motors: none

The idea of this construction was to simply show the strength and precision provided by the linear actuators. The chassis consisted of 4 wheels build so that it could be easily towed in any direction. It housed a single linear actuator controlled by a manual crank. This was also the first time mr Fluffy was used as a model (and as a load test), which met with a very good reception.

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