Original Year	1982
# of pieces	266
Categories	Other: Universal Sets
Dimensions	various
Models	Car Windmill Forklift Helicopter Truck

8090 Universal Building Set

The set 8090 was released in 1982 as the third and largest Universal Building Set. It includes full instructions for 5 models as well as photographs of several other possibilities. There a number of parts left over when any of the models are built, but the Truck model uses the largest proportion of the parts. The part count may not look impressive, but there are ten 16L beams here, so some very large models are possible. There would not be another Universal Set with such large models for a long time.

Unlike set 8030, the models in this universal set cover a wide variety of subjects and complexity levels. The car features a 1 cylinder reciprocating engine, a rear differential, and rack and pinion steering. The windmill features rotating main and lateral vanes. The forklift features rear rack and pinion steering, a 4 bar linkage to raise the forks, and a "kneeling" front suspension. The helicopter features rotating main and tail rotors. Finally, the very large truck features a 1 cylinder reciprocating engine, a rear differential, rear suspension, and rack and pinion steering.

I find the Forklift the most interesting, and it is the model I chose to keep assembled for my display of this set.

1^st Model: Car
This little car has rack and pinion steering, a reciprocating one cylinder engine, and a rear differential gear. The front wheels can be steered using a wheel in the cabin. The wheel drives an 8 tooth pinion gear through a universal joint. The pinion drives the steering rack. The steering mechanism itself uses control arms and toothed links. The engine uses the offset axle holes of the 24 tooth gears to make a crankshaft. Connectors placed end to end and clocked 90 degrees form rods which connect to a specialized 2x2 square piston. The "cylinder" is actually square. The engine is driven from the rear axles through a trio of 24 tooth gears (see color coded image). The rear axle features a differential gear. It incorporates a built in 28 tooth ring gear which can work either as a bevel or a spur, similar to the 24 tooth crown gear. It is made to house 3 14 tooth bevel gears. One is on each axle, and one planet gear in the middle allows the axles to turn at different rates. This addition results in very smooth turns for this model. Oddly, this model does not make use of the shock absorbers which are part of this set.	Click to download the LDraw file of this model. Model by Jerome Boulanger Click for an animation of the steering in motion. Click for an animation of the engine in motion.
2^nd Model: Windmill
This model is a very nice looking, and very tall, windmill with rotating primary and secondary vanes. A crank (made of a 40 tooth gear) located in the back of the structure near the bottom drives a vertical axle through a set of 14 tooth bevel gears. This vertical axle drives a fairly complex gear box at the head, shown in the computer image. The vertical 8 tooth pinion drives a 24 tooth crown gear attached to the axle of the main rotor. This same crown gear also drives a pair of 24 tooth spur gears, one on each side, which rotate opposite directions. These, in turn, drive a second set attached to the secondary rotors. Because of the gearing, all the rotors turn at the same rate which is 1:3 with respect to the input crank.	Click to download the LDraw file of this model. Model by Jerome Boulanger Click for an animation of the windmill in motion.
3^rd Model: Forklift
This forklift is a very nice, fairly complex model. It features steering, lifting forks, and a kneeling front suspension. The rear wheels can be steered using an overhead "hand of god" wheel. The wheel drives an 24 tooth crown gear through a universal joint. The crown gear mates with a perpendicular 16 tooth spur gear attached to a pair of pinions. The pinions drive the steering rack. The steering mechanism itself uses control arms and toothed links. The forks are lifted via a 4 bar linkage. As can be seen in the computer image, the lower links are shorter than the upper links. The result of this is that the forks tips back as they are raised, which can be seen in the animation. A lever attached to a toothed connector is used to rotate the upper links and lift the forks. This is a case where significant torque is carried across the teeth of the bushing, but it performs admirably. A pair of 24 tooth spur gears on the other side are used as a ratchet with a weighted pawl. This keeps the forks raised. The front axle features a differential gear. It incorporates a built in 28 tooth ring gear which can work either as a bevel or a spur, similar to the 24 tooth crown gear. It is made to house 3 14 tooth bevel gears. One is on each axle, and one planet gear in the middle allows the axles to turn at different rates. In this model, the differential ring gear is not attached to anything, so it really only follows along with the front axles. A pair of springs on either side of the front axle swing arm allow the entire model to "kneel". This allows the forks to slip under a pallet before lifting.	Click to download the LDraw file of this model. Model by Jerome Boulanger Click for an animation of the steering in motion. Click for an animation of the forks lifting. Click for an animation of the forklift kneeling.
4^th Model: Helicopter
This fairly large helicopter features rotating main and tail rotors. A crank on the port side drives both a 24 tooth crown gear and a 14 tooth bevel gear. The crown drives a 24 tooth spur gear on the main rotor shaft. The bevel gear drives a perpendicular axle which, through another set of bevels, drives the tail rotor. Because of the gearing, both main and tail rotors are 1:1. The model also uses shock absorbers on the front of the skids. This is an odd feature which doesn't seem to mimic any part of a real helicopter, but does provide some dampening on landing, I suppose.	Click to download the LDraw file of this model. Model by Jerome Boulanger Click for an animation of the rotors in motion.
5^th Model: Truck
This large truck has basically the same features as the car, with the addition of peculiar rear suspension. The front wheels can be steered using an overhead "hand of god" wheel. The wheel drives an 24 tooth spur gear through a universal joint. The spur gear mates with a perpendicular 24 tooth crown gear attached to a pinion. The pinion drives the steering rack. The steering mechanism itself uses control arms and toothed links. The engine uses the offset axle holes of the 24 tooth gears to make a crankshaft. Connectors placed end to end and clocked 90 degrees form rods which connect to a specialized 2x2 square piston. The "cylinder" is actually square. The engine is driven from the rear axles through a set of 8 and 24 tooth gears (see color coded image). The rear axle features a differential gear. It incorporates a built in 28 tooth ring gear which can work either as a bevel or a spur, similar to the 24 tooth crown gear. It is made to house 3 14 tooth bevel gears. One is on each axle, and one planet gear in the middle allows the axles to turn at different rates. This addition results in very smooth turns for this model. The rear axle also features a swing arm suspension, but the motion is forward-aft instead of left-right. The effect of this is that the drive shaft pulls backward when the suspension travels, usually causing the u-joint to separate. The frame is very weak because it is only one beam deep, causing the chassis to flex quite a bit under load. This is really the first long truck model that LEGO^® made, and this problem would be fixed with stiffer frames in later models.	Click to download the LDraw file of this model. Model by Jerome Boulanger Click for an animation of the steering in motion. Click for an animation of the suspension in motion. Click for an animation of the engine in motion.

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