Red Raccoon

At last, the project that has been residing on my desk since March is finished, and here is its result ― the largest and heaviest Technic vehicle I have built so far. As expected, developing an off-road car of this size proved just as challenging as a racing car. An off-roader is more generous in terms of volume and component layout, but on the other hand, its chassis has more complex mechanical requirements to satisfy.

Length: 58 studs
Width: 27 studs, 29 including tyres
Height: Variable, bodywork only: 21 studs
Weight: 2.79 kg
Suspension: Full independent
Power: Power Functions and NXT; 8 motors, 2 pairs of lights
Drive: 2x PF XL motor, 4WD
Steering: Independent front and rear steering, 1x NXT motor with Ackermann geometry each
Features:
  • independently adjustable front and rear ride height
  • lockable central and half-axle differentials
  • 5-speed gearbox
  • drive, steering, differentials, ride height and gearbox remotely controlled
  • headlights and rear lights
  • openable roof (to change battery packs) and bonnet

The first design stage required a development of a good half-axle component that, besides drive and steering, allows ride height adjustment and has a lockable differential via control axle. When I have settled on a working and compact design (which can be seen on the photos below), I've used it symmetrically for both front and rear axles, with some minor changes required at the front to allow the bonnet to close. The central section of the chassis, which connects these two half-axle components, houses a master differential which is linked to the output axle of the gearbox. Two NXT motors, positioned at the sides of this central chassis section, control the steering with a standard rack & pinion mechanism. I've tried to keep them as low as possible to lower the center of gravity, important for off-road stability.

Red Raccoon is powered by two parallel PF XL motors linked into a main power axle with knob wheels, which leads to a 5-speed gearbox at the rear of the car. It is actually a variant of Sariel's linear gearbox, modified so that it doesn't require a 16L axle (whose order and delivery, I have to confess, I haven't had enough patience to wait for), for a price of being one stud longer. As all linear gearboxes do, this one needs slower speeds to shift gears reliably, but in practice it works quite well. Its important advantage is its ability to change gears using one simple motion ― moving the middle axle ― which is done with a liftarm connected to an NXT motor. That was also one of the main reasons for introuducing NXT to the car: an NXT motor can perform very precise movements, in this case in steps of 60°-30°-30°-60°, required to change gears accurately. The gearbox output axle leads, as mentioned earlier, to the master differential.

All three differentials (one master and two on the half-axles) can be locked with a single remotely controlled XL motor, which is attached to a system of clutches and arms that engage and disengage dog-rings on each of them. However, since the master differential intentionally locks more slowly than the half-axle differentials, in both ways, with good timing (matter of a few seconds) one can also lock only the half-axle or only the master differential, rather than having just the option to lock or unlock all of them together.

Remaining two motors have the task of adjusting the front and rear ride height. Each of their output axles is connected, through a clutch, to two cascaded worm gears that turn small 2L liftarms on which the entire suspension (with springs) rests. With their turning range of about 135°, both ends of the chassis can be raised or lowered for about two studs, while the springs themselves allow for about two studs on top of that.

The lights are just standard two PF pairs, and the difficulty was not in positioning them, but rather in trying to avoid their miles of wires getting tangled into gears sticking from everywhere. The roof can be opened to replace the PF battery pack or an NXT smart brick easily. The bonnet opens too.

As one can notice on the photos, cramming all these batteries, motors and mechanics within the bodywork constraints meant there would be no room for interior decoration, even in a rather large model like this one. However, I've tried to keep the top 3-4 studs below the roof empty, to give at least some impression of this car having windows. Mentioning the bodywork, once again I went in the direction of "conventional" Technic design comprising mostly of angled beams, panels and an occasional soft axle, but leaving enough openings to reveal the mechanics inside. The bodywork is studless, as is the entire car actually, with a single exception of a rear PF infrared receiver support.

One more effect of cramming lots of equipment was a deeply asymmetric internal component layout, resulting in the car having a slight off-balance ― it leaned slightly (about one half a stud) to the right, which was solved by small readjustments of the suspension.

The current wheels based on Technic Medium rims with the tyres from 8880 can be replaced by the old Technic 24x43 wheels, visible on one of the photos. This change slightly increases traction on very rough terrain, but reduces performance on flat, fine surfaces. One can easily mount these old rims to the hubs with two Technic pulleys and a 3L axle with a limiter, per wheel. Being of roughly the same size and similar steering pivot point, this replacement doesn't require steering or wheelspace geometry changes.

Since the car is controlled both through PF and NXT, I've built a controller that has a shallow cradle for my mobile phone (used for NXT control via Bluetooth) between the PF IR remotes. That altogether is quite large for a typical hand so perhaps not the most elegant way, but it works.

The overall performance of the car is satisfactory, and it handles sharply if both steering axles are used. Also, all the components and features of the car work reliably, and the chassis is strong enough to allow rough driving and occasional drops without any damage. However, since it follows the form of an SUV more than of a standard all-terrain car, its ground clearance may not be sufficient for really hard-core off-roading.

One more point that should be improved by the successor is the steering. It could be a bit more stiff ― weight of the car now produces grip for which the control components need significant force to overcome, and due to many parts involved that incur backlash, slack and bending, it's not always easy to handle. This would, though, require a significant redesign of half-axle components, in turn demanding a redesign of the entire chassis. And at least a small fake engine and a bit of interior would be nice, but would require increasing the overall size by about 15-20%. Why not?

GALLERY

 

BASIC VIEWS

 

GENESIS

VIDEO

Flashback: 8653 Enzo Ferrari 1:10

We will conclude this recent mini-series of Technic supercar flashbacks with a short look at an 8653 Enzo Ferrari. However, I feel a bit uneasy about that ― as it's doubtedly classifiable as Technic and is mechanically inferior to flagship supercars. It belongs to a small series of Ferrari-licensed models, including F599 and F1 cars.

Its key point is easily visible already on the first photo ― of course, its bodywork design. This is, without any doubt, one of the finest examples of the modeling levels achievable primarily with Technic parts. As such, building it is an interesting lesson about creating those subtle angles and slopes, so often required to achieve desired contours. And the bodywork is not all static: the complex doors that open at an unusual (but realistically recreated) angle and are connected to pneumatic dampers, are clevely constructed. The bonnet opens too, but instead of complex dual-ball-joint system, this one simply rotates around pins and axles. Altogether, stellar design job done ― anyone would instantly guess it's a Ferrari, even without stickers.

However, as some may have experienced a similar effect in many other respects in life, looks can be inversely proportional to amount of wits inside; and unfortunately, the 8653 is no exception. It seems as the amount of design requirements (accurate bodywork, openable doors and a V12 engine) left no playground for extra functionality. It's not that the set itself is small or poor with parts (it's smaller yet has more parts than an 8880!), but a vast majority of them is bodywork or its supporting structure.

Yes, the aforementioned V12 engine works as it's connected to the rear differential, and Enzo can be steered with a HoG knob behind the cabin, too. But there's not much else. Perhaps some space could have been found for a simple gearbox at least...? I feel that some renowned builders would cram 4x4, Power Functions, pneumatic ride height adjustment, onboard fusion reactor and who knows what else in the given constraints. For this reason, this shouldn't be considered a pure Technic (in fact, it is not sold as one ― it's in the Racers theme instead).

As one would expect, it is quite simple to build, with instruction steps being short and usually single-threaded. So putting together those 1358 parts goes rather easily. Among these, there are some valuable parts such as an assortment of red curvy panels, nice sporty tyres, pneumatic shock absorbers and bits of suspension (which sadly aren't utilised for more than keeping the wheel hub firmly in place).

All put together, it has its undeniable highlights such as design and the door mechanism, but it is below the complexity standard set by flagship models. Or, simply said, in the real world it's definitely a supercar, while in the Lego world it's more of a "nicecar". (To joke a bit ― how would it be any more than that, with a 53F/47R weight distribution?)

Once again, it is not sold as Technic in the first place, and therefore it's harsh to judge it by different standards. But one can't dismiss the question in the back of his head: would at least elementary suspension have been too much to ask for? But guys at The Lego Group are not dumb ― they knew the appeal of a Ferrari brand would attract much wider audience than just the Technicheads and had to adjust this car accordingly, while not forgetting about the serious Technic supercars. Can we really blame them for not biting the hand that feeds them?
And now, I'd better stop publishing reviews already and get to these MOC's pronto! :)

Flashback: 8880 Super Car

The 8880 Super Car is famous enough to be difficult to come up with anything about that hasn't been said already. But having finally acquired one and built it with great curiosity, I want to offer my bit to the Technic shrine.

In terms of functionality, complexity and breaking new ground, this car is still leading the pack of all the Technic cars so far, and is among the most important Technic sets since their beginnings in the late 1970's. It has the number of functions even modern Technic supercars (such as the 8070) hardly match, and is arguably the flagship of all studded sets.

Its part count of 1434 seems modest compared to some heavy modern sets that surpass 2000 parts, but in fact, in terms of functionality it's brilliant. The count is rather explained by its bodywork: it's built from a skeleton of large beams that form contours, instead of being covered with panels, air intakes and other fiddly details that often consume dozens of parts. Agreeably, 8880 might look a bit rough-edged and crude for today's picky standards, but personally I like this building style a lot, and find its looks stellar. Besides, this bodywork was a huge improvement over its predecessor, the 8865.

The feature list is, as mentioned, massive ― let's start with the suspension. While the 8865 Test Car already had the full independent double wishbone suspension, this was a first set which had this sort of suspension powered, thanks to a few newly introduced parts. All four wheels were powered, both pairs linked through a differential and, in turn, both pairs linked through a third differential, achieving complexity unheard of at the time. In addition, all four wheels are steered (rear a little bit less than front) ― which would make this car, if it were real, exceptionally agile.

Central differential is connected to a 4-speed synchronized gearbox with H-pattern, another new Lego system which is still widely used today, and which is a solid step forward from the linearly controlled 3-speed unsynchronized version from the predecessor. It is connected with a chain to a mid-mounted V8 engine ― the first Technic car engine that used specialized engine block parts with round pistons (also widely used today) and moved away from complex but cumbersome square-pistoned engines with 24-tooth gear-based crankshafts. Number of mechanical parts involved in suspension, transmission and the engine is thus huge, and it feels as a significant resistance to the car moving.

The car is steered through both a hand-of-God wheel near the engine and the steering wheel in the cabin. Another control available to the driver is a lever that extends and retracts headlights, simply rotating them. Finally, the bonnet can be opened and held up thanks to a small arm.

The general construction of the chassis is very clever, using Technic beams and bricks with offset holes to mesh gears at half-stud distances where necessary. Due to nature of studded constructions, plates separating the beams are used throughout the entire chassis, but only where they really help reinforcing the structure, rather than just slamming them everywhere: sign of a well-engineered construction.

Returning to design, despite the beams being only real element of bodywork, one simply can't overlook the amount of effort put into obtaining the correct angles between them, with a combination of pins and horizontal joints. There are also subtle design gems placed all around the model ― a yellow line that runs along the bottom, rear wing slightly bent at the ends, engine radiators, detailed racing seats, dashboard with air ducts and instruments, rear lights, engine fan that turns together with the crankshaft, twin exhaust pipes, and wing mirrors. Also the wide, low tyres are a nice improvement over the off-roady foams typical for the previous cars.

As one would expect, building an 8880 is a great experience, but requires significant patience. Many steps require careful measurements, precise observation of schematics and occasional bending to fit components in place. In accordance with standards at the time, the building steps in the instruction booklet are very large and concentrated, often following several "threads" at various places in the car at once. Almost like the mid-90's idea books!

It took quite some time for the 8880 to get any kind of succession ― the following supercar, 8448, was released five years later ― and while it had also brought new ideas and concepts, it did not quite redefine the horizon like the 8880 did. Actually, no Technic car since did so as much ― even the latest 8070 is technically inferior to 8880. But I think there is still room (and demand) for a new flagship supercar that would be its true successor, introducing lots of new concepts, parts, ideas, and packing them all in a large chassis.

Conclusion? Simply: if you can, buy this set! Experience building it is great, and one learns a lot of valuable tricks. It's also a gold mine of studded building material, and ― last but certainly not the least ― it's legendary, certainly one of the most important sets Lego Group introduced in its history, even beyond Technic. For further reading, I'd recommend the excellent article on 8880 written by Blakbird.

And now, I'm considering breaking down and rebuilding the 8880. Again. (But I promise, I will in the following weeks finally get around doing some MOC stuff, too.)

 

BUILDING THE 8880 (TIMELAPSE VIDEO)