- Details
- Category: Technic history 1980s
- Hits: 241
The 2nd generation pneumatic system included a new spring-loaded pump and cylinder, as well as the older pneumatic switch and tubing. The new cylinder was double-acting; it had an intake port on both sides of the piston. By directing air to either port the piston could be raised or lowered. This system resulted in simpler and more reliable circuits then the single-acting system. This arrangement has served as the basis of Lego pneumatics to the present day.
Considered by many the be one of the best Technic sets, the 8862 was the high point in a long line of construction vehicles. The front scoop could be raised and tilted through a series of cross axle/triangle links. The back hoe was operated via 3 separately controlled pneumatic cylinders arranged exactly as in the prototype. Finally a set of rear stabilizers could be raised and lowered via a pinion gear arrangement. The now common use of beams attached with friction pins was used to create the cab framework resulting in a model that not only successfully duplicated the functions of the prototype, but looked realistic as well.
1989 was a major year for Technic. It featured 7 new Technic sets, four of which were Universal Sets, and the introduction of a new double acting pneumatic system. The first two universal sets are relatively small and each builds 4 models. The third universal set features one of the pneumatic cylinders which is incorporated into the 4 models in a number of innovative ways. The fourth universal set includes a 4.5V motor. The forklift features steering and a new chain driven fork mechanism. The power crane, although only the second Technic crane, is packed with features including steering, outriggers, a pneumatic luffing boom which also telescopes and slews, and a cable winch. The backhoe grader is perhaps the most complex Technic model to date and features steering, a front lifting and dumping bucket, a rear pneumatic excavator with a luffing boom, jib, and bucket, a slewing mechanism, and outriggers.
Several new parts were introduced this year including the new pneumatic system, the first liftarm, and a special long gear rack. The pneumatics would be used in this new configuration, virtually unchanged, for decades. Liftarms were a sign of things to come as eventually variations on this theme would replace even the venerable Technic beam.
The old pneumatics had lasted only 5 years, but the replacement was an improvement in every way. The motorized universal set, although only the 3rd set to come with a motor, marked the end of the 4.5V motor system.
In my opinion, 1989 marks the beginning of the golden years of Technic. During these years, many new models were released each year, many of which were quite complicated. Each year marked the introduction of many new parts and building concepts. This would go on for nearly a decade before the dark years set in and Technic would begin to lack any sense of coherence.
Double Acting Pneumatics
This second generation pneumatics, released this year, fixed all the problems of the previous system. The double acting cylinders could be pressurized on either side, allowing significant force to be generated in either tension or compression.
- Actuator: There are two pressure ports, one at the head end for extension and one at the rod end for retraction. The limitation on the force is that the piston head internal to the actuator (or pump) will begin to leak after a certain pressure, acting as a pressure relief valve. Since the annular area of the rod end chamber is smaller than the area of the head end chamber, the maximum tension force of the actuator is smaller than the maximum compression force. This is why most real hydraulic construction equipment orients the actuators so that the power stroke is during actuator extension.
- Pump: The pump has the same lower housing as the actuator. The upper end is a large piston with a compression spring return.
- Switch: The switch is the same as under the old pneumatic system. The switch is really a pneumatic selector valve and is the size of two 1x2 bricks. The outer ports are connected to the two ports of the actuator. The center port runs to the pump. When the switch is at the center position, all ports are blocked. When the switch is moved to one position or the other, one of the outer ports and the center port are connected to the distribution block and the other is vented to atmosphere.
Compression Summary: Depression of the pump produces pressure. Pressure flows to center port of switch. Pressure flows out enabled port to actuator head end, extending it. Return pressure from the rod end vents through the other port of the switch. Return of the pump draws in air through the switch.
Tension Summary: Depression of the pump produces pressure. Pressure flows to center port of switch. Pressure flows out enabled port to actuator rod end, retracting it. Return pressure from the head end vents through the other port of the switch. Return of the pump draws in air through the switch.
Liftarm
The new liftarm part is 1x4 with an axle slot at each end. 3/4 of the part is 1/2 stud thick, with the far end a full stud thick and notched to fit between 4 studs on a plate or brick. This part could be used as a crank and served as the prototype for many other sizes and shapes of liftarms to come which would be used prolifically for decades.
Rack Gear
A new rack gear was introduced which is much longer (1x20) than the old 1x4. The gear teeth are recessed rather than standing proud of the base plate like the old rack. This rack is used principally to telescope long structures such as the boom of a crane. It's uses are not limited to Technic and, in fact, it was only ever used in one Technic model.
Fork
A special part was introduced to act as a fork for forklifts. It was only ever used for this purpose in Technic (on 4 different fork lifts). It is quite rigid and can support considerable weight.
Hook
A new hook part was the first all metal part in Technic. The significant weight of this part helped to keep the cables attached to it pulled taut.
Weight
A special brick appeared (new to Technic) which was 2x6x2 and filled with ballast. It was only ever used in three Technic sets to counterbalance heavy structures which could otherwise tip.
1989 sets:
- Details
- Category: Technic history 1980s
- Hits: 269
The new steering gear assembly is a good illustration of these new highly specialized elements. The assembly consisted of a rounded plate with a toothed bracket, a rack/steering rod and a pinion holder. The pinion holder would engage the teeth of the bracket, allowing it it remain fixed in various positions. Because the rack had a rounded profile the pinion could rotate around it and remain engaged. This same functionality would require a much bulkier assembly if constructed out of separate elements. This steering gear has served as the base of steering, especially in small models, to the present day.
This was the first Technic airplane and still stands as their best. By this time Technic sets had mostly lost their block-like construction and were starting to become quite realistic in appearance. The design of the prop plane, especially of the wings and rudder, look like a cutaway of a real plane. This technique would become the staple of 3rd generation set design. The joystick in the cockpit realistically controlled the ailerons and rudder through a series of cross axles and universal joints. The final result is a model that captured the prototype in both form and function. It is perhaps the most underrated Technic set ever.
1988 featured four new Technic sets incorporating a host of new features and parts. The buggy has new rack and pinion steering and rear suspension. The excavator features rear steering and a lifting and dumping scoop. The first airplane, a very large model, features a 1 cylinder engine, movable ailerons and elevators, and a figure. Last, and by no means least, the 3rd generation auto chassis is the first with a body. It also has retractable headlights, movable seats, a V-4 engine, a differential, a 3 speed transmission, front rack and pinion steering, and 4 wheel independent double wishbone suspension.
There was also a supplemental set released this year which included 3 Technic figures. Given that figures were only previously available via Arctic Action and would only come in a handful of other sets until 1995, this was a good opportunity to add some to your models.
Many of the new parts introduced this year would become standard on the Technic sets for years to come, especially the new steering system, though it was used in only one set this year. The 3 blade propellor on the airplane was used on only this one model, ever. The airplane and the auto chassis represent the last sets to use the rectangular pistons which would be replaced in 1990.
Parts
Flexible Steering System
To compliment the existing rack and pinion steering system and steering arms, a new steering system was introduced. The steering arms and lower support remain the same, but the upper support now has an integrated rack support, as shown at right. Another special hollow part snaps into this support and can rotate around the lateral axis. This part ratchets inside the lower support to stop at discreet angles. This part is specially designed to fit an 8 tooth gear to use as a pinion. Finally, a flexible rack gear connects the steering arms. It is flexible so that it does not need to translate forward and back as the control arms rotate, instead it just flexes. Because the rack gear itself is round, the pinion gear can rotate around it and allow the steering column to be at any angle.
An example of a steering system using these new parts is shown in the lower picture.
This steering setup would be used on a vast number of models for many years to come, especially the small sets (under 150 parts), but only one set in 1988.
Steering and Suspension System
Another steering system was introduced, this time in combination with a double wishbone suspension system. The first important part is the control arm (shown in blue). These are typically used in pairs with an upper and a lower part forming double wishbone suspension. The end of the control arm has a ball joint socket. To fit in this socket is a new steering arm (shown in white). It has a ball joint at the upper and lower end, and a cruciform slot to connect to a steering tie rod. As can be seen, the steering connection is offset from the ball joints which allows Ackerman type steering. A new ball joint pin (shown in gray) fits into the slot in the steering arm. Finally, tie rods (shown in black) have a ball socket at either end and fit between the steering rack and the steering arm.
This steering system is typically used with shock absorbers on the lower control arms to make a double wishbone suspension. This is only done on the largest models.
An example of a steering system using these new parts is shown in the lower picture.
Ribs
A set of new tapered beams were introduced which are typically used as aircraft ribs, but have many other uses. The smaller parts tapers on both the upper and lower surface over a distance of two studs. The longer part tapers only on the top over a distance of 4 studs.
Steering Wheel
A new steering wheel was introduced which is typically only used in the large auto chassis sets.
Propeller
A specialized aircraft propeller was introduced. It has 3 pitched blades and a built-in 1x4 beam. Behind the beam is a 24 tooth gear which has the same teeth as a spur gear but has no central axle hole. Instead it has an offset axle hole meant to drive a piston. The gear cannot be removed from the propeller. This part was only ever used in one set, 8855, perhaps because the old square piston system was replaced before another airplane was released.
1988 sets:
- Details
- Category: Technic history 1980s
- Hits: 232
The Robot represents probably the last of second generation sets. The model was a truck that, when the wheel on the back was turned, transformed into a robot. The set featured a rather complex gear train consisting of a worm gear, several reinforced spur gears and a long rack. Turning the pulley wheel simultaneously raised the cab and shortened the wheelbase. In addition to the now standard use of beams, steering arms, toggle joints and cross axles, the model also used a number of non-technic elements, such as claws and train windows.
In 1987 LEGO® only released one Technic set, presumably because so many were released the previous year. The same thing was done in 1985, so twice in 3 years only one set was released. Set 8852 is a truck with steering which transforms into a robot. Subsequent years would yield a plethora of new sets.
- Details
- Category: Technic history 1980s
- Hits: 268
The Arctic Action theme
The smallest of the Arctic Action sets and the smallest Technic set to date, the 8620 was scaled for the new action figure. The model had only one real function-the rack and pinion steering. The steering used not only the typical toothed plates and steering arms but featured an angled steering wheel held in place by cross axles and toggle joints. This small buggy would form the prototype for an increasing number of smaller vehicles over the next several years.
There were eight Technic sets released in 1986, the most ever up to that point. Two of these are universal sets, two are standard Technic sets, and four are something completely different. These last four are the Arctic Action sets, which are so unique that they are covered separately on their own category page. They represent a play theme and are all part of the same connected system. One of the two new universal sets is motorized, and both feature a wide selection of fairly unorthodox models, which is a good thing. The go cart features steering and a one cylinder engine. The new tractor features a pendular front axle and a worm driven implement lift.
Interestingly enough, though this was the first year after the pneumatic system was introduced, there were no new pneumatic sets other than the Arctic Action base. There were, however, some very important new parts including the worm gear and 2 and 3 blade rotor parts. Most unexpectedly of all, new Technic figures were introduced which are much larger and more articulated than the standard LEGO® minifigs. These figures would be used in many sets for many years, especially those which featured the "Tech Play" label. There are 6 figures in the new Arctic Action sets alone. Arctic Action is also the first place that white beams could be collected in large number.
Parts:
Worm Gear
The new worm gear made it possible to achieve very high gear reductions in a very small space. The worm gear is single threaded, which means that it moves one tooth for each revolution. Since each of the spur gears can mate with this screw, gear reduction of either 8, 16, 24, or 40 times can be achieved in a single stage.
The other advantage of the worm gear is that it cannot be backdriven. To understand why, we need to use a little Statics. When a spur gear tooth pushes on the worm gear, it produces a force in the axial direction, along the direction of the axle. But the worm teeth are not perpendicular to this force because of the pitch angle of the screw, so the screw works like an inclined plane. The force can be broken into two components. The tangential component tends to try to rotate the screw. The normal component tends to try to slide the screw along the axle, but it also produces a frictional resistance in the same direction as the tangential force. If the friction is bigger than the tangential force, the screw cannot turn. Since the tangent force and the friction both increase proportionally to the applied gear force, the gear can never turn no matter how hard you backdrive it. If the pitch angle is big enough, or the friction coefficient low enough, some worm gears can be backdriven. An example is a recirculating ballscrew such as are sometimes used for automobile steering or commercial aircraft horizontal stabilizer trim.
This worm gear has only ever been made in one size and, until recently, was only available in black.
Rotors
A pair of parts were introduced which are commonly used as rotors, with 2 and 3 blades respectively. They both have a cruciform slot in the center to allow them to rotate with an axle. They then have a stud which can be used to attach plates or other parts, and finally a hole on the tip. These parts would end up getting used in lots of applications other than just helicopter or airplane blades.
Technic Figures and Accessories
Technic figures were introduced this year. These are not only much bigger than the standard LEGO® minifig, they are vastly more posable:
- Neck: 3 degrees of freedom (ball)
- Shoulders: 2 degrees of freedom (front-back, up-down)
- Elbows: 2 degrees of freedom (front-back, in-out)
- Wrists: 1 degree of freedom (rotation)
- Hips: 2 degrees of freedom (front-back, side-side)
- Knees: 1 degree of freedom (front-back)
- Ankles: 3 degrees of freedom (ball)
A number of accessories were also introduced for the figure. A special seat (pictured) was specially made to fit the figures, although many sets later used it even without the figures. There are helmets with transparent visors. The Arctic Action sets also have skis and ski poles.
Wheel and Tires:
This year a new tire was released. From the name probably for the theme 'Model Team', because it is named tire '13 x 24 Model Team'. Including a new wheel 'Wheel 30mm D. x 13mm' in color white initially.
1986 sets:
- Details
- Category: Technic history 1980s
- Hits: 238
The lost year for Technic. After the release of the pneumatic sets in 1984, many of which were not released in some markets until 1985, and anticipating the Arctic Action series of next year, Lego produced only 1 new set for 1985, the promotional 1972 go-Cart. which was designed as a starter or trial set.
- Details
- Category: Technic history 1980s
- Hits: 230
The 2nd forklift and first pneumatic model. The model's construction was typical of mid 1980's sets. It relied heavily on Technic beams, connectors and rounded plates rather than standard bricks. The model featured rack and pinion steering controlled by a 2x2 round brick on the top and movable forks controlled by a chain and pneumatic piston.
The small universal set is an introduction to Technic, while the larger universal set is an introduction to pneumatics. The forklift features a pneumatically lifting fork and rear steering. The excavator has 3 pneumatic actuators to control the boom and a large number of tracks for the base.
This pneumatic system would only last 5 years and, in fact, only one more model would ever be released which used it. Also new for this year were a threaded axle and a special bucket for the excavator.
This first generation pneumatics, released this year, are exciting but were short lived. The single acting system has some serious limitations which were corrected in the second generation of pneumatics.
- Actuators: There are two different lengths of linear pneumatic actuators which differ only in stroke. There is a single pressure port on the head end side of the cylinder. Using this port, the actuator can generate both compression (via pressure), and tension (via suction). The limitation on the compression force is that the piston head internal to the actuator will begin to leak after a certain pressure, acting as a pressure relief valve. The limitation on tension force is that there is no such thing as suction! Rod end pressure generated by the atmosphere actually pushes the piston the other way to produce tension, so there can never be more than atmospheric pressure generating tension. This means that if you bring your excavator along with you when you summit Mt. Everest, it won't work very well.
- Pumps: The standard pump is identical to the actuator except that it has a spring on the rod. There are two pumps which both use the short cylinder, but differ in using either the long or the short rod. The one with the short rod has a short stroke because the spring bottoms out before the piston is fully compressed. The other can achieve full stroke. One of the limitations here is that suction is only generated by the force of the return spring unless you actually pull the rod up.
- Distribution block: This little gem is the magic behind the single acting system, and in fact the system would not work without it. It is the size of a 2x4 brick but has 3 pneumatic ports. The center port is for input from the pump. Each outboard port contains a check valve so that flow can only occur in one direction. Both are connected to center. The left port is for suction, and the right for pressure. Both of these ports are connected to the switch.
- Switch: The switch is really a pneumatic selector valve and is the size of two 1x2 bricks. The outer ports are connected to the two ports of the distribution block. The center port runs out to one or more actuators. When the switch is at the center position, all ports are blocked. When the switch is moved to one position or the other, one of the outer ports and the center port are connected to the distribution block and the other is vented to atmosphere.
- T-fitting: This splitter can be placed either between the distribution block and one or more switches, or downstream of a switch to allow multiple actuators on a circuit.
Tension Summary: Return of the pump produces suction. Suction flows to center port of distribution block and out of left port. Pressure flows to enabled switch and out center port to actuator, retracting it. Depression of the pump blows out air through the switch via the right port of the distribution block. (This is all backwards since suction is really atmospheric pressure, but it works for illustrative purposes.)
Bucket
A new single purpose bucket was introduced for the excavator which was only ever used in one other model.
Threaded Axle
A new threaded axle was introduced. It has the same cruciform cross section as the regular axle but is also right-hand threaded. With the addition of the new nut, this axle can now carry significant tension load instead of just compression and torque. This allows it to be used to hold unstable structures together (like the superstructure of the excavator). The nut fits between 4 studs to lock in position to a plate, and two nuts can be jammed together to lock them to the axle.
3L Axle
This is the first year that a 3L axle was available, the first odd length. No other odd lengths would be available for a long time.
1984 sets:
- 8020 - Building Set
- 8040 - Building Set
- 8843 - Fork-Lift Truck
- 8851 - Excavator
- 8889 - Idea Book
- Details
- Category: Technic history 1980s
- Hits: 229
The Dragster featured rack and pinion steering connected to the steering wheel via cross axles and 2-cylinder engine attached to the rear axle by a spur gear and differential. A chain drive attached to the spur gear spun a cross axle, simulating a cam shaft. The dragster achieved a somewhat realistic appearance by using pulleys for the narrow front wheels and the large Technic tires for the rear. The tapered body, with an interesting blue and white color scheme, was achieved by using hinged bricks. The original steering linkage proved too fragile and later versions had an insert page showing how to rebuild a stronger linkage. Overall an interesting and rather difficult to find model.
A couple of new beam colors were introduced as well. The dragster was the first to use white, a color which remains quite rare to this day. Despite the commonality of light gray, it had not been used for beams before but two of them are included in the dragster.
The only new part for this year was a tire tread which fit the small pulley. This was rarely used as a tire, but was used as a steering wheel occasionally.
Beams
This year also introduced the first white and light gray beams in 16L and 2L, respectively.
- Details
- Category: Technic history 1980s
- Hits: 240
Lego has always produced specific model sets, but it wasn't until the advent of distinct themes in the late 1970s that this became the primary focus of Lego marketing. Rather, Lego produced generic sets that offered ideas for a wide variety of models, such as the classic 100 series sets of the early 1970's. The Universal Sets were the first generic Technic Set.
The sets came in three different sizes from small to large, and one set included an electric motor for the first time. Motors had previously been available in supplemental sets, but this was the first time one was included with a standard set. The small red set builds mostly vehicles with steering. The blue set builds similar models but adds a motor. The yellow set is quite large and also includes a single piston reciprocating engine and a differential gear.
The friction connector was also introduced this year. It is hard to believe that there was ever a time when Technic sets did not include this part. It is, without a doubt, the most numerous part in Technic history with some later sets including hundreds of copies! It would come to dominate the construction method of Technic beams, but this year was the first time it was seen.
Perhaps the most ubiquitous of all Technic parts, the friction pin, was introduced this year. At first it may look just like a standard Technic pin, but there is an important difference. Standard pins rotate freely within the holes in beams, and are removed fairly easily. The friction pin has axial ridges along its length which make it fit snugly. So snugly, in fact, that it is extremely difficult to remove them. A later modification to this part would fix the problem, but early pins are notoriously difficult to remove without resorting to metal tools which damages the part. One solution is to make a tool as shown in the lower picture to push them out.
4.5V Motor
Also new for this year was the first motor actually included in a regular set. This motor runs on 4.5V using a battery box with 3 C-cell batteries in series. The motor is DC, so there is no incorrect way to hook up the wires; reversing the polarity simply reverses the direction. The motor output is a standard Technic axle form to accept gears, but it also has a slot in it which can drive a belt. The battery box is the same profile as the motor but much longer. There is also a three position switch (forward-off-reverse) which can be placed in series between the motor and the battery box.
The same motor was previously available in Supplemental Set 870, but with a different battery box. This motor was only ever included in Universal Sets and Supplemental Sets.
1982 sets:
- Details
- Category: Technic history 1980s
- Hits: 236
and truck, the 8848 Power Truck. It is interesting to note that after only 4 years Lego had already replaced the original tractor, helicopter and auto chassis with new, 2nd generation models. This very narrow scope of subjects, primarily cars, trucks, motorcycles, and construction/farm machinery, would continue until the late 1990's.
One of the first of the 2nd generation models, the 8848 Power Truck featured rack and pinion steering using toothed plates and the new steering arm, a rear axle differential, the front scoop and rear bed that could be raised and lowered via levers in the cockpit. The model made significant use of the new toothed elements, which allowed the technical functions to be scaled down in terms of size and resulted in a very realistic model.
1981 boasted the largest number of new sets (5) since the first year, and included some very important new parts.
A new helicopter replaced the old and added retractable gear. A buggy was the first small model to feature working suspension. A tow truck was introduced which has a very large number of features for its size, including two winches and a wheel lift. A large truck features a dumping bed and lifting scoop. Finally, a large new tractor (harvester) was introduced with a reciprocating engine and a wide range of available implements. More pinned construction was used than in the past, and a few new parts really changed the way models were built.
Toothed connector elements were introduced which allowed axles and links to be locked together at a variety of angles. These parts were used extensively in 1981, and appeared on every model. A 1/2 pin was introduced which was only one stud wide. This has become one of the most basic Technic parts to this day. Finally, and most importantly, specialized steering elements were introduced which replaced the much bulkier 2x2 turntables previously in use. These parts would be used on virtually every new wheeled vehicle for the next decade, and on many beyond.
Toothed Connectors
A series of toothed elements were introduced which allow assembly at positively locking angles. The basic element, the toothed connector, looks very much like the old connector (which was retained), but has some important distinctions. The end with the cross hole is now only 1/2 stud wide, and is shifted to one side so that another connector can be mated with it and the pair will remain a total of one stud wide and be centered on the perpendicular axle. The orthogonal hole has a cruciform slot to lock onto an axle like the old connector.
The most important areas of the new connector are the toothed ends. There are a total of 16 teeth around the circumference, allowing the part to be mated with other toothed elements at any angle which is a multiple of 22.5 degrees, including of course 90 and 180 degrees. A very subtle design detail makes this possible. The teeth are not perfectly aligned with the axle slot, but are rotated 1/2 tooth width (11.25 degrees). This makes it possible to mate two parts at parallel and perpendicular angles and be perfectly aligned.
Besides the connector, several other toothed elements were introduced. A toothed bushing is 1/2 stud thick with an axle slot. Also, toothed links from length 4 to 8 can be used as regular building elements via studs in the middle, or as specifically angled links using the toothed ends.
1/2 Pin
A new 1/2 pin allows new construction possibilities. Since it is only 1 stud wide, it is not useful for connecting two beams like the old pins. However, one end protrudes slightly and has a stud on it which can be used to attach traditional studded elements.
Control Arms
A control arm part was introduced which was specifically designed to be part of a steering system. This part has an upper and lower pin joint which allows rotation around a vertical axis. A perpendicular hole along this axis is used for a wheel axle. Another cruciform hole on an arm is used as the tie rod input. A sample steering assembly constructed of these elements is shown in the picture.
Wheels and Tires
A new, smaller set of 20x30 foam wheels and tires was released which matches the style of the existing 24x43 tires nicely.
1981 sets:
- 8710 - Expert Builder Parts Pack
- 8844 - Helicopter
- 8845 - Dune Buggy
- 8846 - Tow Truck
- 8848 - Power Truck
- 8859 - Tractor
- Details
- Category: Technic history 1980s
- Hits: 228
8860 Auto Chassis:
The second of the major Auto Chassis and the last of the first generation sets, using a high percentage of regular Lego bricks but also utilizing the new shock absorbers and differential gear, the model featured rack and pinion front wheel steering. A three speed manual transmission, rear wheel independent suspension and a 4-cylinder boxer engine. Probably the last of the first generation models, the 8860 still relied heavily on standard bricks and beams, it even used Homemaker faucets as part of the manifold.
In 1980 only two new models were released, but most of the original sets from previous years were still available.
The new auto chassis replaced the old, and improved upon it in almost every way with an impressive list of old features (reciprocating engine, gearbox, rack and pinion steering, adjustable seats) as well as new features (a working differential, rear independent suspension, and reclining seats). This set showcased everything Technic could do, but still was constructed with a large number of traditional bricks and plates. The auto engines set was released only in the USA, and featured 4 technically accurate engine models with full instructions. Both sets could be motorized using the 4.5V motor available separately.
Some very important new parts were introduced this year including the differential, the 14 tooth bevel gear, and the shock absorber.
Parts
Differential Gear
A specialized differential gear was introduced. The ring gear, which has 28 teeth, can act as either a spur gear or a crown gear due to the tooth profile (like the crown gear). This part is made to be used in conjunction with 3 of the new 14 tooth bevel gears. One bevel gear goes on each side attached to an axle, and a third acts as a planet gear and rides on a pin in the cage. The assembly acts like a real differential in every way: wheels can turn at different speeds or together, wheels turn opposite directions if the ring gear is fixed, and one wheel drives at double speed if the other is held.
The new 14 tooth bevel gears were the first gears LEGO® made which were purpose-designed to work on perpendicular axes. The gear is only 1/2 stud thick and the teeth do not have any back iron (webbing between the teeth), so it is a bit weak, but future iterations would correct this.
Shock Absorber
The shock absorber was an important step. Finally, models could have real suspension. This part was eventually used for other purposes, including holding mechanisms over center.
The shock absorber consists of a telescoping mechanism inset with a helical compression spring. The spring is quite stiff compared with the weight of parts it typically supports. The shock bottoms before the spring reaches solid height.
Pulley
The new pulley is smaller than the previous, and has a nice round groove for driving belts or rubber bands. It is also only 1/2 stud thick, so it fits in smaller spaces.
Plate
The new 3x2 plate with a centered hole on one end can be used to support axles or pins, and is a way to align studded construction with Technic beam holes, which are located halfway between the studs.
1980 sets:
- 858 - Auto Engines
- 8858 - Auto Engines (US release of set 858
- 8860 - Car Chassis
- 8857 - Motorcycle (US release of set 857 - Motorcycle)
- 8888 Expert Builder Idea Book