Model of a GG Quad. Features full suspension, return-to-center steering system and a powerful propulsion system.  

Datasheet:

Completion date: 15/05/2011
Power: electric (Power Functions)
Dimensions: length 34 studs / width 22 studs / height 20 studs
Weight: 0.895 kg
Suspension: front: independent / rear: dragged axle
Propulsion: 2 x RC motor, direct drive
Top speed: 9.6 kmph
Motors: 2 x RC, 1 x PF Medium

My first model which turned out so fast that I was unable to film it inside my apartment. Original GG Quad is a quad/sport car hybrid, a vehicle that’s useless off-road but extremely fast on road. It’s faster that most of the cars or bikes, because it weights less than a car and it’s more stable than a bike, without the need to slow down around corners. There is also a newer, more powerful version called GG Quadster, but it appeared ugly to me.

Technically, the model is pretty much a copy of my Scania racing truck, with a few changes. These include a return-to-center steering system (created by simply using this piece), a direct drive, that is no gearing used on the rear axle, and a fully studless, lighter body frame. Just like the Scania, it has an independent front suspension and a dragged rear axle, with two coupled RC motors used to connect the rear axle to the chassis. The motors are powered from separate batteries and through separate IR receivers due to their extremely high power consumption, so the model has in fact two independent power supplies and control systems, with motors being only coupled physically by the rear axle.

Aesthetically, I was trying to make the model as light as possible without compromising its look too much. It was clear from the beginning that a model with roughly one third of the chassis occupied by batteries alone can’t be made very authentic, but I’ve been trying to find an acceptable compromise. The weight of the bodywork is around 150 grams, so it constitutes a small part of the model’s total weight. It was also necessary to make model as robust as possible, given its speed and the fact that I was forced to drive it outdoors.

The model certainly has two disadvantages: the front wheels tend to fall off, and the handlebars are fixed. The problem with the front wheels is that I used simple axle pins to hold them in place, and it worked well until the axle pins started to wear out. They were brand new at the beginning, and they looked really shabby in the end. The problem with the handlebars is that making it turn with the front wheels would result in increased weight and complexity, with the latter making the model less robust.

The model was fun to play with, and the fact that it wasn’t much faster than my Scania despite being 50% lighter shows that I haven’t used the full potential of the RC motors. I suppose that the next step is to use a gearbox that would allow to switch between RC motor’s slower and faster output remotely. Experimenting with various wheel sizes could also give some interesting results.

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Model of a concept bike. Features full suspension, drive and lights but no steering.

Datasheet:

Completion date: 31/01/2010
Power: electric (Power Functions)
Dimensions:  length 44 studs / width 16 studs / height 16 studs
Weight: 0.73 kg
Suspension: full with shock absorbers, left and right wheels connected together
Motors: 1x PF Medium

I like unusual vehicles and I like bikes, so I got interested in Dodge’s crazy concept bike (4 wheels and a 500 HP engine) quite a time ago. I wanted to build smaller, not motorized version earlier, but I eventually focused on a medium-sized motorized model.

The goal was to make it driven remotely, with full suspension, and looking as accurate as possible. Steering turned out to be impossible – the real bike has left and right wheels suspended independently, and is steered by tilting left / right.  With the LEGO model, it became apparent that both front and rear suspension needs a solid axle connecting two wheels in order to maintain the proper stiffness. Since there was no place for another motor anyway, I decided to give up the steering completely.

The model was eventually not entirely accurate, but it maintained the size and the silhouette of the original vehicle.  All electric and almost all mechanic parts were covered up, the model was fitted with front and rear light and an integrated on/off switch. I liked its look and I consider it an interesting experiment, even though it was not so really  fun to drive only straight ahead

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A monowheel-like vehicle, but with 5 wheels altogether.

Datasheet:

Completion date: 11/04/2009
Power: electric (Power Functions)
Dimensions:  length 32 studs / width 19 studs / height 28 studs
Weight: 0.69 kg
Suspension:  none
Motors: 2 x PF Medium

Once in a while I get a spontaneous idea, which seems so little time-consuming that I build it right away. So it was this time – the Q Bike was built in just two days. I was initially going to call it an O Bike, but then I thought that the little rear wheels deserve a mention too – hence the Q.

The idea was simple – since I couldn’t build a real monowheel (it only becomes stable at large speed), I cheated a little. The addition of small rear wheels not only allowed to steer easily, but also provided a satisfactory stability. You may note that they are, perhaps unexpectedly, facing forwards – it makes it easier for the bike to reverse. The vehicle’s center of gravity is moved to the back, which prevents it from gerbiling forward when stopping. All the electric elements which form most of the vehicle’s weight are located symmetrically, except for the wires which are somewhat counterbalanced by the fake exhaust on the other side. The vehicle only becomes unstable when stopped suddenly while making a tight turn.

It was my goal to create a vehicle looking more realistic than my Diwheel, which had no place for driver whatsoever. Hence only a minimal amount of the main wheel’s internal space is taken by mechanics, so that there is a place for a large seat and a handlebar (which can be folded forwards to access the seat).  I have added an upper set of headlights plus side view mirrors to make the front and the rear of vehicle easier to distinguish. The front part of the vehicle is empty – I felt it would not be realistic to put there anything that may block the driver’s view.

I was happy with the bike’s performance (and the visual side was, well, satisfactory), as it showed a good stability and an excellent manoeuvrability. I only regret that I wasn’t able to make the handlebar really work – but I feel justified given the limited amount of space and the very inconvenient location of the motors.

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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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Model of a very unusual type of bike, located inside parallel wheels. Features advanced drivetrain with a subtractor, and lights.

Datasheet:

Completion date: 16/09/2008
Power: electric (Power Functions)
Dimensions:  width 22 studs / diameter 25 studs
Weight: 0.84 kg
Suspension:  none
Motors: 2 x PF XL

Some of my constructions result from a research in the history of technique. This is a very good example – model of one of the most unusual vehicles ever. It originated from the concept of a monowheel, that is a bike located entirely inside a single wheel, and steered by the tilt of driver’s body. Such a concept exists for more than one hundred years, and has been implemented in most various ways. Since I became interested in the study of the physics of gyroscopes at the same time, my original idea was to build a gyro-stabilized monowheel. Pretty soon, it became obvious that the only original Lego wheel of appropriate size is the unique Hailfire Droid Wheel, present only in the 4481 set. Luckily, I managed to buy almost complete set at an affordable price.

Prior to building the vehicle, I’ve tested a number of gyroscopes made from Lego bricks and driven by Lego motors (usually the 2838 motor), only to discover the pretty obvious truth – that the stability of a gyroscope cannot be transferred to the entire vehicle by mechanical means. It can be only done by advanced electronics, that monitors position of the gyroscope and adjusts the vehicle’s position accordingly (which is why e.g. Segways are expensive). Upon learning this, I’ve dropped the idea of a monowheel, and confined myself to a diwheel.

Diwheel is something not too far from two connected monowheels. It uses two parallel wheels instead of a single one, and is located entirely inside them, just like the monowheel. Diwheels are obviously more stable, and easier to steer. Still bewitched by the sleek look  of a monowheel, I decided to make my diwheel look as close to it as possible – which involved locating wheels very close to each other. Eventually, there was only 1-stud-wide gap between the wheels, and the motors have been moved to the sides of the model.

Having big wheels  so close to each other means that a minimal difference in their speed is enough to make a turn. This, plus the fact that I wanted the model to be reasonably fast, prompted me to use a subtractor in the drivetrain. It was a perfect solution, that could provide high speed and precise steering at once. However, the longitudinal subtractor, which I have used many times before, wouldn’t fit inside the model. Therefore I have designed a transverse version. It fit in perfectly, and performed well enough – actually better than I expected, and during the first test drives I just kept adjusting the differential’s gear ratios to make the model go faster and faster.

Eventually, the vehicle turned out to be quite fast, yet not fast enough to experience problems with traction that could result from all-plastic wheels and lightweight construction. Because it could only run at one speed, starting and stopping the model caused it to swing forwards and backwards. While it could not make it fall over, not even while turning, it would be surely disaster for an actual driver. To prevent the diwheel from gerbiling during such a manoeuvre, I’ve added elements that can be called front and rear bumper, but that turned out to be needless after all. The model’s stability resulted exclusively from the low placement of its heaviest elements, that is the battery box and the motors. It was perfectly able to drive and turn on a flat surface, but would sometimes fall to side while climbing over an obstacle. To make the model appear more like an actual vehicle, and make its front distinct from its rear, I’ve added a set of lights: three blue ones in front, and a single red one in the back of the vehicle.

Although the model did not meet some of my assumptions, it enjoyed a lot of worldwide attention from both Technic and non-Technic builders. I, however, still considered the issue of model’s speed not completely solved – I was sure that it could benefit from a gearbox, preferably an automated one, which would eliminate the swinging effect resulting from starting and stopping at full speed. Moreover, the look of the model could have been much better in my opinion.

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Media reference:

Klocki, TechnicBRICKs, The Design Blog

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Small trike built for relaxation at the beginning of a new year. Features rear axle drive, V4 piston engine, full suspension and functional handlebars.

Datasheet:

Completion date: 02/01/2008
Power: electric (Power Functions)
Dimensions: length 56 studs / width 22 studs / height 20 studs
Weight: 0.85 kg
Suspension: rear – independent with shock absorbers / front – fixed shock absorbers
Motors: 2 x PF Medium

Just a simple project for relaxation after long work on a big mobile crane. The challenge here was to incorporate a battery box into the construction is such a way, that there would be still some place for the steering system left. I eventually achieved it, and there are diagrams of the steering system on the photos below.

The front wheel is suspended on two fixed shock absorbers, but in a way allowing it to go up – I considered it necessary given the extreme caster angle of the wheel. The rear wheels are suspended on longitudinal rocking levers, which makes for a narrow independent suspension. The drive motor, except for providing a decent speed, drives a V4 piston engine behind the driver’s seat. The entire vehicle was somewhat out of proportion, but I greatly enjoyed driving it around.

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Small quad, built around the battery box. Features full suspension, rear axle drive, front winch and functional handlebars.

Datasheet:

Completion date: 11/11/2007
Power: electric (Power Functions)
Dimensions: length 31 studs / width 22 studs / height 23 studs
Weight:  0.84 kg
Suspension: front independent/ rear dragged axle on shock absorbers
Motors: 2 x PF Medium

This construction was a precious experience in compact building. It’s virtually built around the battery box, in a very tight way. Except for the box and two motors, it includes an IR receiver, a B2 piston engine (in the boxer setup), and the suspension. One motor drives the rear axle, the other controls steering with the functional handlebars.

The bike performed pretty well in all tests, was fast and manouverable. The most noteable feature was the footage filmed with a camera located on the driver’s seat, which is included in the video below.

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