Each step of the building process includes a short list of pieces that are required during this particular step, and my fault was not being attentive enough. On the other hand, I would say that massive sets like this one lack check points that will help you try all the mechanisms as they are being assembled. Being able to find a mistake as early as you made it would save a lot of time, but discovering one small mistake 3,000 pieces later is a little bit heartbreaking.
There are several robotics competitions which use the Lego robotics sets. The earliest is Botball, a national U.S. middle- and high-school competition stemming from the MIT 6.270 Lego robotics tournament. Other Lego robotics competitions include Junior FIRST LEGO League (Jr.FLL) for students ages 6–9 and FIRST Lego League (FLL) for students ages 9–16 (age 9–14 in the United States, Canada, and Mexico). Jr.FLL and FLL offer real-world engineering challenges to participants. FLL uses Lego-based robots to complete tasks. Jr.FLL participants build models out of Lego elements. In its 2010 season, there were 16,070 FLL teams in over 55 countries. In its 2010 season, there were 2,147 Jr.FLL teams with 12,882 total student participants in the United States and Canada. The international RoboCup Junior football competition involves extensive use of Lego Mindstorms equipment which is often pushed to its extreme limits.[53]
Here is the official description of the set: Harness the awesome power of the CLAAS XERION 5000 TRAC VC! Experience the ultimate in farming technology with this 2-in-1 LEGO Technic reproduction of the high-powered CLAAS XERION tractor. This meticulously detailed replica comes with the trademarked green, gray and red color scheme and an array of authentic features and functions. Turn on the included Power Functions motor and you can raise the cab and turn it through 180°, operate the versatile crane or extend the outriggers. The vehicle’s front-wheel, 4-wheel and crab steering provide ultimate maneuverability with the huge tractor tires ensuring optimal grip for immense pulling power on all types of terrain. Rebuild the tractor’s crane to create a CLAAS XERION 5000 TRAC VC with Silage Plow! CLAAS XERION 5000 TRAC VC with crane arm lowered measures over 11” (30cm) high, 24” (61cm) long and 7” (18cm) wide, and over 14” (37cm) high with crane arm raised. 1977 pieces. Price: $179.99 – BUY HERE
Let me take the time and say to you Blakbird, that I truly love your site. First of all it give me a quick access to looking at different sets through the years, including descriptions of functions.  But the part with most value for me, is the description of the new parts for each year. As a part designer this is really interesting, learning the history of the Technic pieces, and I don't even know if I could quickly find something similar as an employee. That is why I also eagerly awaits the future beyond 1994. But serious stuff like this takes time, so don't rush it please.
Here is the official description of the set: Operate the powerful Volvo EW160E! Enjoy a rewarding building experience with this awesome 2-in-1 LEGO Technic model. Developed in partnership with Volvo Construction Equipment, this meticulously detailed replica of the Volvo EW160E, with its classic yellow and black color scheme, has all the features of the real-life wheeled excavator. Operate the versatile pneumatic boom and grabbing bucket, rotate the massive superstructure and elevate the cab for optimal visibility. If you need extra stability, extend and secure the outriggers, lower the front blade and lift the entire structure into the air! The authenticity of this model is without bounds, right down to the detailed cab with seat, armrests, sun visor and adjustable mirrors. Upgrade with the #8293 LEGO Power Functions motor set (not supplied) and you have a fully motorized boom and working lights! When you feel like another building challenge, rebuild it into the heavy-duty Volvo L30G compact material handler. Volvo EW160E with boom and outriggers retracted measures over 6” (17cm) high, 9” (25cm) long and 4” (12cm) wide, and over 11” (29cm) high, 18” (47cm) long and 7” (18cm) wide with boom and outriggers extended. Volvo L30G with bucket lowered measures over 6” (17cm) high, 13” (34cm) long and 5” (13cm) wide, and over 10” (26cm) high with bucket raised. 1166 pieces. Price: $119.99 – BUY HERE
These are called power parts by LEGO Technic, and they help make the models move and increase the interactivity. These are great options for young children as they can play more with the construction toy after it is finished. Check out customer reviews and videos, as often people will comment if they were able to add these kinds of parts in after building and will give instruction booklets on how you can do it too.
Lego (Danish: [ˈleːɡo];[1][2] stylised as LEGO) is a line of plastic construction toys that are manufactured by The Lego Group, a privately held company based in Billund, Denmark. The company's flagship product, Lego, consists of colourful interlocking plastic bricks accompanying an array of gears, figurines called minifigures, and various other parts. Lego pieces can be assembled and connected in many ways to construct objects including vehicles, buildings, and working robots. Anything constructed can then be taken apart again, and the pieces used to make other objects.[3][4]
Although liftarms (studless beams) have been present in Technic sets since 1989, the change from primarily studded to primarily studless construction around the year 2000 represented a major paradigm shift and has been quite controversial. Initially liftarms were use primary as styling parts, or to create smaller sub-assemblies which attached to a studded chassis. With an increasing number of liftarm designs introduced, a tipping point was reached around the year 2000 with models introduced primarily constructed from liftarms instead of traditional beams.
Here is the official description of the set: Experience the huge Bucket Wheel Excavator! Enjoy building and operating this massive 2-in-1 Bucket Wheel Excavator, the largest LEGO Technic set to date! This awesome, meticulously detailed reproduction of a real-life mining excavator comes with a cool dark-blue and yellow color scheme and an array of authentic features and functions, including hand-railed walkways, huge tracks and a detailed cab. Switch on the included Power Functions motor and you can activate the conveyor belts, rotate the massive superstructure and maneuver the colossal machine into position. Then activate the boom to lower the gigantic, digging bucket wheel and convey the mined material to the waiting mine truck. When you feel like another building challenge, rebuild it into a Mobile Aggregate Processing Plant. Bucket Wheel Excavator measures over 16” (41cm) high, 28” (72cm) long and 11” (29cm) wide. Mobile Aggregate Processing Plant with boom retracted measures over 8” (21cm) high, 34” (88cm) long and 8” (21cm) wide, and over 12” (33cm) high with boom extended. Mine Truck measures over 3” (10cm) high, 7” (19cm) long and 3” (10cm) wide. 3929 pieces. Price: $279.99 – BUY HERE
Over the years, several new pieces were introduced in this line as well. The new pump was spring based, and could only be operated by hand, which limited pneumatic power to how fast it could be manually pumped. This obviously limited the power of pneumatic circuits. So in 1992, LEGO introduced two new pieces; a small pump and a small cylinder. The small pump did not have a spring on it, and it was designed to be operated by a motor, which would allow for continuously-running pneumatic creations. As of 2011, the small pump has only appeared in one set — 8868 Air Tech Claw Rig (1992) (found on Peeron) — and a few parts sets (no longer available). A new version of the small pump was released in Lego set 8110 Unimog U400 (2011). At 2L, this pump's stroke is 1/3 longer than the old one's 1.5L, 'L' being the LEGO unit of a stud. This made it much easier to use in studless construction.

The LEGO company at that stage had no idea how much it cost to manufacture the majority of their bricks, they had no idea how much certain sets made. The most shocking finding was about sets that included the LEGO micro-motor and fiber-optic kits — in both cases it cost LEGO more to source these parts then the whole set was being sold for — everyone of these sets was a massive loss leader and no one actually knew. This was combined with a decision to 'retire' a large number of the LEGO Designers who had created the sets from the late 70's through the 80's and into the 90's and replace them with 30 'innovators' who were the top graduates from the best design colleges around Europe. Unfortunately, though great designers they knew little specifically about toy design and less about LEGO building. The number of parts climbed rapidly from 6000 to over 12,000 causing a nightmare of logistics and storage and a huge amount of infrastructure expansion for no gain in sales. Products like Znap, Primo, Scala and worst; Galidor all came out of this period.
Although I’ve not built many Technic sets, I had a few when I was a kid and in recent years tackled the VOLVO L350F Wheel Loader. Things have changed greatly between the sets I built in the 80s to Bugatti. The new Technic system which was introduced in the early 2000s has lead to a collection of models which continue to innovate and challenge. Would I of have purchased this set, if I didn’t have the opportunity to review it? Probably not but I would be missing out on a genuinely unique LEGO experience. An experience which begins from the moment you lift the lid and feast your eyes upon its perfectly arranged boxes.

In 1989, the LEGO pneumatic line was revamped, and a new cylinder and pump piece were introduced. The old cylinders and pumps were discontinued. The chief difference is that the new cylinder had two input valves now, which allowed both pushing and pulling without needing complex circuits involving the distribution block piece. The Generation 2 cylinders also had metal rods so that they more closely resembled real hydraulic cylinders.