Model of the legendary 60′s racing car. Features full suspension, remote-controlled drive, steering and turn signals, lights and custom stickers.  

Datasheet:

Completion date: 17/01/2012
Power: electric (RC unit)
Dimensions: length 67 studs / width 31 studs / height 17 studs (not including antenna)
Weight: 2.35 kg
Suspension: full independent
Propulsion: 2 x RC motor geared 5:1
Motors: 2 x RC motor, 1 x PF Medium, 1 x micromotor
Top speed: 2.2 kmph

Ford GT40 is a classic racing car with a beautiful history. It was built for one purpose only: to defeat the Ferrari team in the Le Mans race – a goal set by Ford after failure to buy out the entire Ferrari company (Enzo Ferrari changed his mind in the last second). To understand the gravity of this challenge you should know that the Ferrari team won Le Mans six times in row starting from 1960.

The basic design of the car was purchased by the Ford from Lola Cars company owned by Erica Broadley and located in Huntingdon, UK. It can be therefore considered originally a British car. However, Ford spent several months working on car’s aerodynamic properties, under supervision of former CEO of the Aston Martin company, before it was considered race-ready. The finished car was the fastest car of its time, and it won Le Mans race four times in a row between 1966 and 1969 year. When it debuted in 1966, three GT40s have won three first places in the race. Keep in mind that we are talking about race that involved brands such as Ferrari or Porsche – it’s difficult to think of any modern Ford car completing such a task.

The original GT40s were built in a limited number, and the number of “civil” versions was even smaller, making it one of the world’s most often copied cars in the years to follow. It can be roughly estimated that the number of replicas today is several times greater than that of the original cars. Around 2002 the Ford company decided finally to create a new edition of the car, which was supposed to be as close to the first GT40 as possible. In reality, it was largely different, including being taller than 40 inches – a number the GT40′s name originated from – and it was therefore named Ford GT. Due to many differences some Gt40 enthusiast consider the new edition “softened” or completely ignore its existence. You can see the differences between new version (in front) and the old one (in back) below:

If you are looking to learn more about this legendary car, you can see a dedicated Top Gear episode here, and you can listen to how it sounds here.

Ford Gt40 is called the most beautiful car ever made by some – which is arguable, given the fact that its look does not stand out so much from the look of other cars of its era. In fact, it’s strikingly similar to some cars built around the same time (e.g. Lamborghini Miura P400 version S) or even slightly earlier (e.g. Porsche 904 GTS). As large models of supercars give little room for functions (no space) or for performance (weight), my goal was to make the model look real and authentic. Out of many versions of the GT40, with many details looking much differently, I have chosen the Mark II version – one that had a history of engine failures, but that also included many interesting and unique details, including air intakes on top of the rear bonnet. Some other details, such as the absence of side mirrors, show that it’s a racing version of the car. My decision to build the body of the model fully studless was strengthened by seeing a Ford GT40 model by Arvo brothers. I consider them to be among the world’s top studfull builders but their studfull model does not appeal to me – and I don’t think I could possibly top it.
Most of all I wanted to model the shapes of the car properly, looking for a balance between using beams, panels and flexible axles. I was looking for something between the approach of the LEGO 8448 set (body made of just general contours with gaping holes) and that of some older cars by Crowkillers (fully enclosed bodies made primarily of beams).  Some compromises proved necessary – the roof was a single part, without parts of it being attached to doors, because I was unable to find a good-looking solution to that. The front bonnet did not open and the rear bonnet was inaccurate – it should open with all side air intakes attached to it, but it only opened with the top two.

Most difficult part of modelling the body was the front of it, particularly the front mudguards and headlights. If you look at front of the Gt40, its mudguards follow a complex curve which slightly rises towards the sides of the car. I wanted to model this feature, which I consider crucial in making the model look accurate, and I think I achieved that using large panels set at complex angles, with flexible axles drawing the outer body contours. The headlights, on another hand, are nearly rectangle-shaped and come with vertical ribbing, typical for headlights of all cars of that time. I eventually used blocks of 1×2 trans-clear plates, which I think look accurate, but they absorb much of the light of the Lego LEDs behind them.

The model had only driver’s seat in the cabin, and it was moved to the side because of the RC unit occupying the center. The dashboard was completely inaccurate – it rested on top of the bearing frame, so there was no space to experiment with shaping it. The exhaust pipes were tilted downward a little more than they should, allowing the rear bonnet to open up further. Behind the cabin, there was a simple, static mock-up of the engine with some details, but less than I intended to include – I didn’t want to make the model heavier than it already was.

The construction of the model was 95% studless, with only rear axle using studded bearing structure around the differential. The bearing frame was built around the RC unit which was moved forward into the cabin, practically right next up to the front axle. The frame was rigid, but not completely – therefore the rear bonnet could be locked to the back of the cabin, thus providing extra stiffness to the top-rear part of the body.

While the model was not technically complex, it was challenging to integrate all the functions I wanted it to have with the RC unit and with the way it works.

The propulsion system consisted of two hard-coupled RC motors connected to the rear axle’s differential with 5:1 gear reduction (that is larger reduction than shown on photos – I had to increase it after taking photos). The transmission system also included a Lego speedometer, with the display integrated into passenger’s side of the dashboard. The model is rather slow – I was hoping to keep its weight under 2 kg, and with the final weight being much larger the motors were so strained that the batteries in the RC unit lasted about 5 minutes.

The suspension used typical Lego double wishbone independent suspension, with two short yellow shock absorbers per each wheel. It was soft, particularly the rear axle which carried most of the model’s weight. Just like in the original car, the front suspension is slightly narrower and the rear wheels wear bigger tires – in this case, tires were enlarged by putting two rubber treads over each of them. It should be noted that the model drove better without the treads that with them.

The steering system used steering output of the RC unit. The RC steering module could not be used because it was much too narrow. The steering wheel was attached to the RC unit’s output too through a series of gears. The steering lock was small – the RC steering unit rotates by small angle, and I couldn’t gear it up because there was no space for large gear wheels under the low bonnet.

The front and rear lights, using three pairs of Lego LEDs, were connected to the same output as the propulsion motors. They only shone when the model was driving, and they blinked when it started because of the RC motors taking all the power available.

The turn signals system, which took quite a lot of work to include, was based on my earlier mechanism. This time, however, it was remote-controlled rather than automated. I simply wanted to try remote-controlling it freely, and besides it would be nearly impossible to use it with the RC unit’s steering output. Instead, it was connected to the RC unit’s auxiliary output and it consisted of two parts connected only with wires – which was necessary to fit it in. First part was a micromotor driving an old 9V switch, located vertically at the back of the cabin, between the RC motors. The second part was a PF Medium motor rotating two PF switches, coupled with old toothed half-bushes so that turning one switch on turned the other one off. I wanted to control them with another micromotor, leaving enough space for passenger’s seat, but it proved too weak.  The turn signals could be made with just two pairs of Lego LEDs, except that their wires were too short. I had to use four pairs instead, and since the GT40 has single turn signals, I ended up with two spare LEDs in front and two in back. I have installed the front LEDs into the dashboard, creating turn signals indicator in front of the driver, and I have simply hidden the two rear ones.

The model had its imperfections and compromises, but in general it was fun, looked good and it was a great experience in studless building. I can say it was slower than I expected but looked better than I hoped. I think the photos of it are among the best I’ve ever made, and I also put a lot of work into the video, with a good effect. It was a good lesson for my future supercars, because it was example of a very typical supercar, with central engine, low ground clearance and rear axle drive.

Work in progress photos:

Photos:

Video:

Click here to view the embedded video.

Media reference:

8 studs (Polish only), TechnicBRICKs, Technic Delicatessen, The LEGO Car Blog

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A static Monty Python themed vignette with a slightly customized minifigure.  

Datasheet:

Completion date: 14/01/2012

I’ve been a big fan of anything related to the Monty Python group for years. Having recently learnt that the famous Black Knight from the no less famous “Monty Python and the Holy Grail” movie was played by not a bit less famous John Cleese, I sort of felt compelled to bring that scene into the world of Lego minifigures.

Click here to view the embedded video.

The main point about making this vignette was to make it instantly recognizable while using minimum customization on the minifigures. I’ve spent a while carefully choosing minifigures’ outfits and faces (well, a single face actually). I only customized what I absolutely had to: the Black Knight’s helmet was originally metallic silver and I painted it with two layers of Revell black matte paint. This was the most fitting LEGO helmet and it does not originally come in black. I have also used two tiny bits of black plasticine to keep the “blood” in place of the Black Knight’s arms.

The creations, simple as it was, provided me with a good opportunity to practice taking close-up photos inside a light tent. It was also my one and only creation up to that that I’ve built with no intention of taking it apart after.

Photos:

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Summary of another year of building and plans for the year ahead.

2011 was a good year for building and for being a fan of LEGO in general, with many new pieces becoming available and an amazingly ambitious 8110 Unimog set being released. For me personally, it was a busy year because I’ve spent large part of it working on my book that will be released in 2012, and therefore I had less time for building that usual. Still, 2011 resulted in 26 MOCs, which is quite a nice number.

The 2011 started with my biggest and most complex MOC so far: the Tow Truck 2, with 17 motors and nearly 19 meters of wires on board. In February I have undergone a surgery and it took me a couple of weeks to recover, resulting in just one simple MOC until April. In April I have started exploring a completely new area of building with the LEGO Monorail system, which is somewhat closed but still brings new challenges and possibilities, different than the ones associated with typical vehicular models. Later, in May, I have created first outdoor video of my MOC for a very long time, and one that I consider very nicely edited, so I will take the liberty of showing it here.

Click here to view the embedded video.

Also in May I have ventured into yet another building area: the marine vessels built entirely out of LEGO, first with my Quadramaran, and then with a demonic Trimaran one month later. The latter was also my first opportunity of making use of the LEGO RC unit – an element I have long wanted to have and finally managed to purchase. Sending it out on a lake for start was perhaps not the safest idea, but luckily it survived

June was an interesting month even without the Trimaran – I have failed at building a hamster-powered crane (the power supply was unwilling to cooperate)  and then I failed again at building a motorized sentry turret from the Portal game – I managed to make it look the way I wanted it to look, but I had to give up on most of the functions I wanted to include in it. Which is, I hope, a lesson for the future. The turret also happened to be my 100th MOC in my adult building career, and it also marked the moment when my YouTube accout hit 5,000,000 total views.

After not doing much in July, I have set my personal record by releasing 6 MOCs  in August. Among them was a Pushback Tug that has reached my goal of towing 20 kg of load with a LEGO vehicle, and two off-road vehicles (one using the 8110 set’s new suspension pieces) which failed to perform as expected, thus prompting me to finally quit participating Truck Trial races. I feel it’s a change for the better, especially since I keep filming these races and I can now focus on it  entirely. It’s worth mentioning than one of these two vehicles included a tiny vehicle inside it, controlled remotely through it, thus being something like a MOC inside a MOC. The rest of the year was less building-intensive with my book requiring more and more time; there were two small-scale tanks, a Monorail creation with 100 minifigures included, and my first vignette.

2011 was also a year I’ve become a YouTube partner. It does not change much in the way my videos are published – some of them will simply be released with some lame, royalty-free background music. I hope you can put up with this, as thanks to this I am able to get some money from YouTube, and they cover at least part of my LEGO expenses. It also seems that I’m getting more views being a YouTube partner, because I have over 7.2 millions of them now, at the end of the year, and that means 2.2 million views just since June.

At 5,999,598 total views halfway through September, the Rodent Overlord was pleased with my progress

All in all, I feel happy with how this year turned out – I have built more than I expected, and I think I’ve reached the goal of building more diversely than the year before. One thing I’m certainly unhappy about is the fact that I haven’t managed to finish a single supercar model, even though I got one mostly complete by the end of the year.

As for the 2012, some of my plans simply include building what I failed to build in 2011 – for example, the K2 Black Panther tank model and a model of the Rusich tank transporter to accompany it. I want the two of these to work together and perhaps I will manage to build them both in matching colours, which should look really well. It’s possible that K2 will be my last tank, at least for a longer while, and I’m planning to put together a roundup of all my tank after its release, because I feel that tanks are particularly good at showing my progress as a builder.

Among other 2012 plans are: a reach stacker, which I’ve been planning to build for really, really long, and an articulated Caterpillar hauler with unique ejector system. I would also like to make another try at building a huge model of a bucket wheel excavator, something I have abandoned two years ago when my model reached 7 kilograms and its chassis couldn’t support it properly. I think I’m now better prepared for such a challenge, and if I succeed, the result can be a truly impressive MOC, probably my biggest one ever.

Other “large” plans include an articulated Solaris Urbino city bus, the type I’m using to commute on a daily basis – I want to build it at large scale, which should be an interesting challenge. Just building a frame that will hold it together is challenging already. I would also like to try to work on something aesthetically pleasing by building a large model of the famous Mercedes Benz 540K Special Roadster, and finally I would like to build a large and complex fire engine based on the Volvo FH16 truck. I want to make it actually shoot water, and it should result in a good-looking and very functional model, something a little close to my aforementioned Tow Truck 2.

LEGO Technic Control Center

The 2012 is also the year of some new possibilities. I have recently managed to buy the LEGO Technic Control Center, which opens up a lot of options, including installing it on some large vehicle (such as the Caterpillar hauler mentioned earlier) and programming it to drive on its own. I have also acquired an EL wire, which can be interesting on the aesthetic side, and has, in fact, already inspired me to make two small and simple MOCs.

EL wire

I intend to keep trying out new things and new areas; some Monorail creations are very likely to come, and I would also like to try to build an amphibious vehicle – something that was suggested many times when I started with the marine vessels. As usual, I keep a few secret projects that are bound to come out into the daylight sooner or later, and I reserve the right to build things on a spontaneous impulse.

2012 is, last but not least, the year my book hits the shelves, and I hope it will live up to your expectations. I am often unable to share my knowledge in an accessible or efficient manner – there is a lot of people who expect me to somehow transfer it by e.g. YouTube comments – so it is my personal wish that the book can help you, guide you, teach you and inspire you, thus being of more use than any comment could be.

Finally, I should mention that I have developed a secondary hobby during 2011: playing a bass guitar. It’s something I enjoy no less than building with LEGO pieces, and while I’m unlikely to become skilled enough to pursue a musician’s career, it will certainly be taking some of my time. Who knows, it may even become a part of some MOC someday?

The culprit – Yamaha RBX 270 J

I feel good looking back at 2011 and even better looking forward at 2012. I want to thank you for following my work through this somewhat though and busy year, and I hope that 2012 will bring you at least some of the MOCs you wish to see.

Happy New Year 2012!

Paul

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Model of the famous WW2 German heavy tank. Features drive, steering, rotated turret, elevated main cannon and lights.  

Datasheet:

Completion date: 21/12/2011
Power: electric (Power Functions)
Dimensions: length 25 studs (36 studs including main cannon’s barrel) / width 14 studs / height 11 studs (not including antenna)
Weight: 0.694 kg
Suspension: none
Propulsion: 2 x PF Medium geared 1:1
Motors: 3 x PF Medium, 1 x micromotor

The Tiger tank is the probably most famous German WW2 tank, and one of the most famous tanks in history. It entered service as a heavy tank in 1942, and it was exceptionally advanced for the time, as well as deadly effective. The tank’s powerful gun and thick armour made it an unprecedented threat to both Soviet and Allied tanks. There is also another side to the Tiger, which states that the tank was over-engineered, extremely expensive and time-consuming to both produce and to maintain, and its fuel consumption was monstrous, especially for the crumbling economy of the after-1942 Nazi Germany. It was also designed in accordance with a doctrine of armoured warfare that was already obsolete – it was intended to win by superior firepower and thick armour, while the Soviet tanks, much cheaper and easy to produce in large numbers, were already winning by manoeuvrability, sloped armour and by working in groups. To make things worse, the Tiger was rushed into service without proper quality control and on-site technical support, resulting in many tanks disabled by technical malfunctions or being abandoned after getting stuck because there were no means to haul them out. Still, it was an impressive and fearsome tank, even if its significance has been exaggerated by the Nazi propaganda. One could say that it was a great tank itself, but it required maintenance and logistics on a level its creators were unable to provide.

As for the model, I was initially going to build it in large scale, with tracks of the newer type, but my primary goal was  to properly model its distinctive overlapping road wheels. This element is often ignored and simplified in the models of the Tiger, and I wanted to get it right. It turned out difficult to do at large scale, but I figured out that I could simply use Technic discs at a smaller one. Since there pieces don’t exist in dark bluish grey colour, I had to settle on next closest to it, that is pearl dark grey.

The model has undergone a rigorous technical control. 

After deciding on a small scale, the main challenge was to make the model fully remote controlled despite its very small size; the finished model’s hull was only 20 cm long and it could fit on the palm of my hand. My secondary goal, besides that, was to properly model the shape of the air filters on the rear of the tank, which are half-round but Lego builders often make them all-round or even rectangular. I achieved this by using four 6191 bricks, which was also a challenge as they only appear in dark bluish grey in a single Lego set, one brick per set.

Eventually, the model had to house four motors, two IR receivers, a battery and approximately 2 meters of wire, plus the large Technic turntable which would provide a stable base for the turret while allowing to install a motor in it. I won’t be dwelling on how hard it was, let’s just say that there were times when the functionality of the model depended on whether I can move some element half stud further or not.

The model was quite simple technically. It was driven by two PF Medium motors located in the middle of the hull, which drove rear sprockets with 1:1 gearing (the only ratio possible as there was no space for any large gear wheels). There was a battery in front of the hull, and a third Medium motor next to it, which drove the turret’s turntable through a worm gear. There was a single wire that entered the turret and powered a micromotor installed inside it, which drove another worm gear and thus controlled the elevation of the main gun’s barrel. There was no suspension whatsoever, and the two headlights on top of the hull had Lego LEDs inside them and shutters made of the bases of Lego levers.

The look of the model was not meant to be consistent with one particular of many versions of the Tiger, I just wanted it to be characteristic, which means that it’s close to the tanks from the early production batches. Its side number – 131 – was not random; the 131 Tiger tank can be found in the Bovington Museum in UK, and it’s probably the world’s only Tiger tank in driving condition today.

The model did not look perfectly; the hull was too tall by roughly 3/4 of a stud, and the turret had a gap beneath it to allow the worm gear to mesh with its turntable. This could be avoided if there was enough space in the hull to ‘sink’ the turntable inside it, but there wasn’t. The turret was 9 studs wide, built around a micromotor and held together by its roof rather than by its bottom. Its look was affected by mechanical parts inside it – its front was too tall and its rear end is a little too far to the back. Finally, the main gun’s barrel’s dimensions had to be heavily approximated at this scale – for example, the longest section of it should be 0.75 stud thick while the thickest section should be 1.5 stud thick. There are simply no Lego pieces with such dimensions that would have the required look.

The model was fun to play with, but clearly suffered from small size and low weight. It’s almost my lightest tank model ever, one third lighter than my T-72M tank and almost as light as my very simple Mark I tank – and it has more road wheels than any of those; 24 to be exact, with only 16 visible from the sides. Therefore its traction was poor and it was difficult to drive over my floor, where any unevenness (and there are many) affected its direction. I believe it would perform much better with more weight, stronger chassis and a simple suspension system, as proved by my earlier T-72 tank model, which had exactly the same tracks and propulsion system. This means that this model is probably example of the level of “miniaturization” that is already bad for its functionality.

Work in progress photos:

Photos:

Video:

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Two interesting mechanical solutions for transmission systems.  

The Oldham coupling and Schmidt coupling are two various mechanical solutions for transmitting drive between two parallel axles that are not aligned in line. That makes them alternative to universal joints, which are long, and to gear wheels, which only fit in specific spacings and affect power/speed ratio if not meshed at 1:1 ratio.

The Oldham coupling consists of two identical rotors, each connected to one axle, and a sliding element between them. The coupling shown here can handle input/output displacement of 1 vertical and 1 horizontal stud. It can be expanded to allow larger displacement by using longer axle in its sliding element, but that increases its diameter drastically. In short, the Oldham coupling is short and maintains 1:1 ration, but is complex, fragile and has large diameter.

The Schmidt coupling consists of three discs or triangles connected with links – three links per disc/triangle, giving six links total. The first and last discs/triangles are connected to the axles while the middle one simply hangs in mid-air. The unique property of this coupling is that it can work while its input and output are moving relatively to each other. That makes it an interesting solution for transferring drive to the moving elements of your construction. The Schmidt coupling is also extremely robust and can handle high torque while generating minimum backlash. Its main disadvantage is the length – in this case 5 studs – and the fact that it’s built around a rare LEGO piece.

Photos:

Video:

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Experimental static vignette illuminated with LEGO LEDs and an EL wire.  

Datasheet:

Completion date: 29/10/2011
Power: 12V (external transformer)

A vignette is a static scene that fits in 8×8 studs area and is usually populated by minifigs. As a Technic builder, I have never built one before, until having a blue EL wire at hand resulted in a sudden and unexpected idea.

The vignette used two levels of dungeons to depict a sorceress from the Diablo game making her way upwards using a lightning bold spell. The EL wire, which simulated the bolt, had been completed by four LEGO LEDs that illuminated lava leaks and a torch on the vignette’s lower level. The upper level was populated by four incomplete skeletons (there was only a leg left of one of them), armed with weapons just like in the game. There two levels of dungeons also included some tenants: a spider on the upper lever and a somewhat concealed bat on the lower one. The two levers were connected by shattered floor and maintained different colour themes. I have also taken a liberty of taking the Diablo 3′s tagline: “And the Heavens shall tremble” and changing it a little:

This was a very simple creation that allowed me to try some light effects. It was nevertheless fun to build and my hamster fitted well in it

Photos:

Video:

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Highly experimental, very simple creation illuminated with EL wire.  

Datasheet:

Completion date: 26/10/2011
Power: 12V (external transformer)

I have a soft spot for LEGO creations with working lights in them, which is why I started to experiment with an EL wire – basically, a wire that works like a single huge LED while being elastic available in various colours and lengths (that can be cut if needed). Even being a LEGO purist, I realize there is absolutely no way to achieve even a remotely similar effect with LEGO parts – hence the experiment.

I wanted to try integrating the wire into something, just to test how elastic is it, how far can it be shaped and how well does it “sit” with LEGO pieces. Being a fan of Razer gaming products, I caught a sudden inspiration to build a 1:1 model of a fictional Razer-inspired headset. Hence the name, because Razer names its products after animals, the headsets are named after aquatic ones, primarily sharks, so Oxyrinchus is a Latin name of one of the sharks species.

The creation was extremely simple, to the point of being crude, but it allowed me to test both the wire and my camera while taking photos of a MOC illuminated this way against a black backdrop. It was therefore an opportunity to get some valuable experience, but it had absolutely no functions beyond that – hence the “expert headset for hearing inner voices” caption

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My fifth Monorail creation, features a single station with three levels, two Monorails and 100 minifigures.  

Datasheet:

Completion date: 05/10/2011
Power: 9V (Monorail) / Power Functions

This creation’s goal was to have three levels of tracks on a single station, and to populate it densely with minifigures. The white Monorail was built first, and I wanted to model it after LEGO Intercity sets, but I came across a number of problems specific to Monorail. For the Monorail to be able to drive up and down the ramps and to fit inside the station, the front and rear of the cars had to be short, and the cars themselves had to be narrow and low. Initially there was sliding door on the side of each car, that would open by coming in contact with rubber axle joiners located at the platform just a moment before the Monorail came to stop. It worked well, but created more problems: the cars were too wide (with doors 1 stud thick) and for the doors to work properly, they would have to arrive and depart in the same direction on all three levels. I have eventually decided that the doors aren’t worth the extra complications and removed them.

The tracks set-up could appear complex, but as demonstrated at the end of the video it was possible to make a Monorail go through all three levels back and forth without stopping. This creation was simple yet enjoyable, and it was my first creation to include some LEGO sets: namely the 7239 set as the fire truck and 7279 set as the thieves/police team with a quad.

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Video:

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Simple vehicle created to test the RC unit and some other elements. Features suspension, 2-speed remotely controlled gearbox and on-board speed computer.  

Datasheet:

Completion date: 24/09/2011
Power: electric (RC unit)
Dimensions: length 63 studs / width 41 studs / height 20 studs (not including antenna)
Weight: 1.314 kg
Suspension: full independent
Propulsion: 2 x RC geared 1:3
Motors: 2 x RC, 1 x PF Medium
Top speed: 13.8 kmph

I’ve had the LEGO RC unit for a while, but only one opportunity to play with it. So, when I bought a couple of the big Exo-force wheels, I decided to use them in combination with the unit and with the RC motors’ output selector that would act as a remotely controlled gearbox.

The vehicle consisted pretty much just of the RC unit with the steering attachment, two RC motors and the gearbox. The front suspension was based on the steering attachment, and the rear suspension used wishbone arms. The rear axle also included a differential for better handling, and was quite wide for improved stability. It should be noted that the vehicle was so low that it could drive upside-down with the antenna removed.

The vehicle also included on-board speed computer that measured speed just near the differential and showed it in RPMs, as it was unable to calculate the final speed for wheels of that size. I had to calculate the speed manually using the wheels’ circumference. The vehicle had no body whatsoever, and it carried two camera mounts: front and rear one.

The final performance, when tested outdoors, proved disappointing in terms of speed. The vehicle was able to go barely 13.8 kmph in perfect conditions. On the other hand it handled excellently and proved quite robust; it also attracted a great deal of attention from a number of wiener dogs. My final conclusion was that the gearbox was needless, whereas the differential was crucial. Without the differential, the vehicle was prone to doing unexpected U-turns when trying to turn at high speed.

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Video:

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Model of a Cold-War era Soviet main battle tank. Features suspension, rotated turret, elevated main cannon and lights.  

Datasheet:

Completion date: 10/09/2011
Power: electric (Power Functions)
Dimensions: length 39 studs (52 studs including main cannon’s barrel) / width 19 studs / height 16 studs (not including antenna)
Weight: 1.057 kg
Suspension: torsion bars
Propulsion: 2 x PF Medium geared 1:1
Motors: 3 x PF Medium, 1 x micromotor
Top speed: 1.14 kmph

T-72 is one of the most popular tanks in the modern world. It has been produced for 40 years now, and the production still continues with over 25,000 total tanks built. It was designed with cheap mass production and maintenance in mind. It offers interesting blend of simplicity and good characteristics, and it generally follows the Soviet doctrine of focusing on quantity rather than quality of tanks. While the T-72s can be easily gathered in large numbers, they usually lose 1:1 encounters with Western tanks.

I have chosen this particular tank because it’s a great example of Cold-War era Soviet tank design, with flattened hull and small, bowl-shaped turret. The US intelligence nicknamed the turret “Dolly Parton” because its shape supposedly reminded her breasts (you are strongly advised NOT TO search for photos of Dolly Parton, for the sake of your good taste). I had two goals while building it: to test the torsion bars suspension in a lightweight model, and to see how small fully motorized tank model can I build.

As for the aesthetic side, there was a number of minor shortcomings. I wanted to properly model the distinctive shape of the turret, because Lego models of the T-72 usually have turret shaped like a slightly gnawed disc. I think I achieved that, at the cost of attaching some details to the bottom of the turret, thus increasing the gap between the turret and the hull’s upper surface. The turret also had very little space inside – so little, in fact, that the majority of the main cannon elevation system had to fit in a 2 studs wide gap.

Other than that, the central section of the main cannon’s barrel should have been slightly thicker, but the only idea that occurred to me was to wrap it in a paper of similar colour and let it pass for a sticker.  I also had the impression that the hull is slightly too tall, even though I was sure it had the right proportions. I could have remedied it easily by decreasing the suspension’s angle and thus the ground clearance, lowering the entire tank, but the large ground clearance is distinctive for the T-72. Perhaps the reason was that the side skirts started a little higher than they do in the real tank.

The T-72 is unusual in how its details are distributed: there is a lot of details on top of the hull’s rear, but almost nothing on the side skirts and above the tracks. I have added some extra details to simulate the kind of “luggage” that some tanks carry on them – in some cases it seems that the tank’s crew grabs virtually anything that comes around and attaches it to the armour.  I have also used Lego LEDs to emphasize the large number of searchlights on the turret, which is very distinctive for the T-72, and I used some Lego plants to simulate the so-called environmental camouflage, just to see the result.

The model was very simple technically. There were two PF Medium motors in the back, connected straight to the rear tension wheels. Together they provided reasonable speed and a surprisingly high torque. The were also two IR receivers in the back, and another PF Medium motor between them, used to rotate the turret. Because of how small the turret was, its entire rotation system along with the turntable was located in the hull. The central part of the hull was taken by the turntable, and the front was taken by the 8878 battery lying transversely on its side. The battery could be accessed by removing the entire glacis plate. The remaining space, which was sparse, was taken by wires and the suspension system.

This was my second tank to use torsion bars suspension – the previous one was almost 3.5 kg heavy, with nearly 0.25 kg load per road wheel, and its suspension worked perfectly. Here the suspension was very similar, except that the axles used as the torsion bars were kept at fixed angle by the toothed half-bushes and toothed connector joints. It saved some space, but it wasn’t working really well because there were gaps at the half-bushes, which I had to fill with tiny scraps of paper. The average load was less than 90 grams per road wheel, and the entire suspension was therefore very hard – it was actually difficult to notice that it works.

I was happy with how the model turned out, even though its aesthetic side had a few compromises to it. It was a good, very agile model to play with, but I think it proved too light for this kind of suspension.

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My third walking vehicle. Features 8 legs based on Theo Jansen’s walking mechanism, driven by two motors.  

Datasheet:

Completion date: 31/08/2011
Power: electric (Power Functions)
Weight: 0.492 kg
Suspension: none
Propulsion: 2 x PF Medium motor geared 1:66:1
Motors: 2 x PF Medium

I wasn’t satisfied with my previous walker which tried to adapt the Klann linkage, so I turned to something else: the Theo Jansen’s mechanism. I started by studying a so-called kinetic horse which uses Jansen’s linkage to move four legs. I recreated the linkage using 5 and 7 studs long liftarms, and I’ve been experimenting on a 4-legged walker for a while. I was trying to make it steered by articulation, but it proved to be unstable. I have then created two identical 4-legged units and connected them together. I wanted the whole walker to be steered by controlling four left and four right legs independently; I have been experimenting with a studless subtractor in the propulsion system, but it resulted in the walker being slow, large and clumsy.

Eventually, I settled for a lightweight body with two Medium motors controlled independently. I have shortened the legs, as longer legs needed longer chassis to maintain the same level of stability. I have also equipped them with rubber tips to improve traction on flat surfaces. The walker created this way turned out to be very efficient, agile and fast, even if very simple. I consider it my best walker up to date, but this is rather thanks to relying on Theo Jansen’s work than on my own solutions.

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A simple, small model of an unique leaf spring catapult designed by Leonardo da Vinci.  

Datasheet:

Completion date: 30/08/2011
Power: wind-up crank
Weight: 75 g

Model of one of the Leonardo da Vinci’s less famous inventions: a catapult using a leaf spring to fire projectiles, which makes it unique in terms of Medieval technology. The original catapult was to use a single wooden leaf spring – an idea probably inspired by a bow. It did not become popular due to high manufacturing costs at the time. There was a number of full-size models recreated today, and they proved capable of throwing stone projectiles just under a quarter mile. My model, whose scale is difficult to determine, can throw a regular Lego ball just under two meters.

It took me a while to find a Lego element of proper elasticity – I eventually settled for two 12 L axles. It seemed that the axles will get bent permanently from the tensions present in the model, but eventually the did not – they turned out to be perfectly straight after disassembly. I believe a catapult using the same principles to work without risking damage to any Lego pieces could be made with two rigid levers mounted on tension bars, but that would look very much different from Leonardo’s original design. I wanted the model to be mechanically accurate; this is also why I didn’t include any arm-stopping mechanism that could potentially increase the range – I simply haven’t found any in the original drawings.

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