The largest Technic set ever, with the largest amount of motors, all controllable by an app. But also the most expensive. Is it worth the money?


The Set
The Box
The Instructions
The Parts
Building the Beast
Controlling the Beast


Just like last year, LEGO, again, releases a 'bigger-than-ever' Technic set. Even more special: This model is completely controlled by the new Control+ app. I must say I'm a bit skeptic on how this will work. Am I right, or will I be proven to be a whiner?

The Set

Get ready for a colossal LEGO® build and play experience with the 4,108-piece LEGO Technic™ Liebherr R 9800 Excavator. Developed in partnership with Liebherr, this replica model is operated via the intuitive LEGO TECHNIC CONTROL+ app and powered by 2 advanced Smart Hubs with 7 motors. The sophisticated app technology enables super-precise movement and amazing functionality, while delivering endless authentic digital play combinations via 4 different control screens with cool graphics. The Multi-function control screen enables users to drive the machine in all directions, rotate the superstructure, extend and raise the boom, open and tilt the bucket, play realistic sound effects and get real-time feedback, such as boom position, power usage and drive distance. With the One-touch screen, users can use drag patterns to control the boom, arm and bucket, while the Custom-built movements screen enables them to choose pre-set commands or record the model’s actions to create complex sequences of movements. And, with the Challenges & achievements screen, users can complete challenges to unlock reward badges.

The Box

The box measures 580 x 475 x 17 mm, which is the same as the 42082-1 Rough Terrain Crane. With 7.01kg it does weigh about a kilo more. The art on the box shows the model, along with a lot of its functions and connection to the app. There is no sign of a B-model!

The box is completely packed, no room for air. Inside we find 15 bags numbered 3 through 6, a loose bucket, a bag of pneumatic hoses, a black box, and a big white box. Looks like stage 6 is going to be a tough one. In the black box are the PoweredUp elements: 2 hubs, 3 XL-motors and 4 L-motors. Inside the white box are 15 more bags numbered 1 and 2, and a bag with 2 instruction manuals and 2 sticker sheets labeled A and B.
I was surprised that there are only 6 build stages (5 if you don't count a bag of rocks...). The 2 sets closest to this set in part-count, the 42082-1 (13) and 42055-1 (8) have more. That means more parts per stage, and I like that.


The Instructions

There are 2 instruction books. They measure 366 x 295 mm. Book 1 builds stage 1 and 2 in 485 steps and 367 pages. Book 2 build stages 3, 4 and 5 (and sort-a stage 6) from step 486 to 1000 on 370 pages. The pdf can be downloaded here when they become available.
In book 2 is a nice side -by-side shot of the real-life model and the Technic version. Also, there is some information on the app. One thing I noticed (and this is nitpicking): The large rings on the real life model are Orange, but on the LEGO model they are Yellow. Normally I would think that this was to limit the number of new color/part combinations. But in this case, the 15100 Technic Pin Connector Hub with 1 Pin with Friction Ridges Lengthwise was specially introduced in Yellow for this model. Could be that there are more upcoming sets that need a Yellow 15100?

The Parts

The set contains 4108 parts and 31 spare parts (although there are a few that might be just parts I missed during build...), in 18 different colors, and 29 different categories, with a total of 225 unique parts/color combinations.

Main colors are:

Main categories are:

New parts:
There are several new parts. First up is the new large bucket 46891.

There are 2 new parts, that together form a clutch, 46834 and 48635. These can be placed in an axle, and will slip when too much torque is applied, saving the motors and gears. Previous this was only possible using a 76244 - Technic Gear 24 Tooth Clutch, but that would always mean you need to go sideways to another gear. This new version can go straight, like shown in the photo below.



The 40918 Technic Linear Actuator with Dark Bluish Gray Ends Long is a very interesting and useful addition. Folded in he's 15 studs long, 4 more than the little brother. He extends 8 studs, 3 more than the little brother. It uses the same bracket.

The 39794 Technic Frame 7 x 11 is not really new. It already appeared in 2 SPIKE sets, but the release for those sets are set back to 2020. It is new in White. EDIT the 39794 is also used in 2019/2020 First LEGO Leagua sets in Magenta.

Also not really new, but worth mentioning are the 22127 PoweredUp Hub 4-Port, 22169 Powered Up L-Motor and 22172 Powered Up XL-Motor.

The new hub has one great benefit over the old battery box: There is an insert that you can take out, to easily place and remove the batteries.
Parts in new colors:

Parts in rare colors:

Building the beast

The soundtrack for this build:

Volbeat: Rewind, Replay, Rebound
Equilibrium - Renegades

Stage 1 builds the lower part of the excavator. First up is 1 side of the tracks.

For those who worry, that all functions will be directly linked to the motors: There is some gearing going on, both in the tracks and the turning of the upper structure.

Next up is the mid-section with the hub and the XL-motor to rotate the upper structure.

And then the only really repetitive part: the other side of the tracks. Luckily this didn't feel really boring, as there is a lot going on in this build.

The finished build: This already feels very big.

After each building stage, there is the option to test the added functions with the app. This way you can track possible mistakes early on.

Stage 2 builds the main body of the upper structure. Before we can build, the turntable needs to be aligned. Why that is, will be explained in the part about the app.

The ports on the hub get color coded, corresponding with the color of the clips that are used for the wires, to ensure correct connections.

Challenge: Who can come up with a less boring pattern?

There is a high level of detail. These engines (I guess? They would also fit a microscale space colony) are hidden out of sight behind the outer panels.

ADD: So, I'm feeling real dumb. Only 2 weeks after building this set, I found out that the panels are doors that open up...

We end up with a big upper body, and the first impressing for the size of this monster. It's HUGE!

Stage 3 builds the arm of the excavator. The arm consists of 2 sections. The first section contains the 3 L-motors.

After rebuilding the second section for the third time, I realized the caffeine content of my blood was low, so I went for a pit stop.

After I managed to build the second section correctly, the 2 get merged. To give you an idea of the size of this build: I could hold it in my arm like a baby... (unfortunately, I forgot to take a picture of that).

Now the linear actuators get added, and the arm can be mounted onto the excavator.

Those wire clips come in handy in here to keep things tidy. As you can see, most of the space inside stays empty.

And the result after stage 3:

Stage 4 adds a lot of details to the model. As you can see, this stage uses more 'normal' LEGO bricks than Technic parts. From this stage on I found the build less interesting, but that's just because I prefer to build expanding a model and get more Technic. But the end result looks very good.

Teasing my wife who has OCD tendencies. She gave me the option to fix it before kicking me out of the house ;-).

Another example of details that get hidden. The fans are hard to see through the stickers, but still they added them to the build. I love this type of dedication.

The hub is accessible through a hatch on top.

End result of stage 4.

Stage 5 finishes the detailing by adding railings, a cabin and a lot of pneumatic hoses. It also adds the bucket, finishing all Technic functions. Much to the joy of my youngest (3), the cabin fits a minifig.


Stage 6 is just a bag of stones for the excavator to dig up. There are 100 of them. What can I say? This obviously done to boost the part count. Without this bag, the part total would be 4008, and that's under the 4056 of the 42082-1 Rough Terrain Crane. This feels cheap. They wanted a 'biggest ever' set for advertisement, and this is how LEGO got it. Nope, I don't like it at all. This is the only really negative part of the whole set.

Okay, you could argue that the 42055-1 Bucket Wheel Excavator does the same thing with the rock pieces. But even without the rocks, the 42055-1 still stays 1000+ parts above the previous largest set at that time, the 42043-1 - Mercedes Benz Arocs 3245 with 2793 parts. In some aspect, the 42082-1 also uses this tactic. Without the Light Bluish Gray prefab wall sections that can be lifted, the part count would stay under taht of the 42055-1. But at least, here the parts are used to build something. In the 42100-1 it's just: Open bag, drop bricks.

Sorry, rant over. Back to the review

The end result is a colossal beast. It feels much larger than the 42082-1 Rough Terrain Crane. I've put it beside the Liebherr for a size comparison. The size and level of detail is impressive. I really feel I have accomplished something after finishing the build. It's gonna be hard to find room to display him.

Controlling the beast

There are 6 functions driven by the 7 motors. The 2 XL-motors in the lower section drive the tracks independently, and the L-motor turns the top section.
In the top section we have 1 L-motor raising and lowering the total arm:

A second L-motor raises and lowers the top half of the arm.

The third L-motor tips over the bucket. Right before the bucket is tipped at maximum, the top half of the arm starts to come down, preventing it from tipping further.

And the last L-motor opens and closes the bucket. This motor has the longest drivetrain, and in my case it's a bit jerky. The drivetrain is mostly hidden within the arm, so troubleshooting is tricky.

All these functions are only controllable by the app. For this review, I received a beta-version, so there might be some minor changes after the release.

As mentioned earlier, after every build stage, there is the possibility to test the newly build functions. For this, the app only has to connect to 1 of the 2 hubs. At the first connection, I had to download a new firmware version. This takes about 5 minutes through a budget phone. After connecting, the functions are tested one by one. The app lets the Liebherr perform a short task, and asks if it's done correctly.


When the build is all done and all test have been performed, you can start to play. But first, there is a calibration. One of the great things about the new motors, is that they register how many rotations they make, and how high the resistance is. That way, it knows in which position the actuators are. During the calibration, the model tries out all linear actuators into their maximum positions. When that is done, the app knows how far the motors can turn both ways. This info seems to be stored on the app, not the hubs. When you extend an actuator to the maximum with device A, and then switch to device B and retract it completely, and then switch back to device A, the app thinks the actuator is extended to the max. So it won't extend any further, and when you try to retract the actuator, the app will keep doing this, even though all gears are crackling. I'm not sure how this could be prevented, but I hope LEGO will add a section to the manual about this. Also, the calibration is sometimes a bit off, letting the motors run too long and cause gear crackling. Maybe that will be updated in the app. There are somehow no clutches in the functions with actuators to prevent crackling. Maybe because that would interfere with the calibration?

And then it's really time to play. The first time, you get an explanation of all controls. Basically, there are 2 sticks driving the rotation and the arm lifts and tipping. There are 2 slides for driving. There are 2 buttons for opening and closing the bucket. Also, there is an indicator showing the power level of the batteries, and the angle of the model in 2 directions.
If you swipe down, a very nice feature appears. Here you see a model of the arm. You can click and drag any joint into a position you like, and the model will go into that position.

And lastly on the controls, there are 4 numbered buttons. Under these buttons, you can add self-made programs. The editor for this looks a bit like the boost and the PoweredUp app for the 76112-1 - App-Controlled Batmobile. Simply drag and drop the movements you want and save. If you use the same series of commands multiple times, you can make a sub-program with it's own tile. Also, you can record movements using the controls, and save that as a sub-program.

To teach you how to control the model, there is a series of challenges you can complete, like rotating the model 180 degrees etc.

Here is a crappy video I made of the calibration and the different functions. I have a budget phone and only a freeware editor. This is not my field of expertise ;-).

Third Party apps
One major disadvantage of the app and the new components, is that it only works for the models that are programmed in. For now, that is the 42099-1 and the 42100-1. Outside of that, there is no official LEGO software to control the motors, and that makes using them for a MOC difficult. Luckily, there are other options. One of these is the BuWizz app. BuWizz is known for its smart brick that let you control PowerFunctions through Bluetooth on your mobile device. There are multiple MOCs here on Rebrickable that uses this brick. Their app also connects to the new components. It lets you customize a control panel with different kind of control buttons. It can connect to 16 hubs at a time, so that should suffice ;-). Simply drag and drop a control, select the output it controls, and play.

As you can see, it's easy to use.

Another app that works is BrickController 2. This lets you program a controller like from PlayStation or X-Box to operate the motors. Unfortunately, I don't have such a controller, so I can't test it. But from what I hear it works very well.

A while ago I talked about the potential of the PoweredUp system. I mentioned The LEGO Train Project, later renamed to The Brick Automation Project. With this system, you can control your trains and program standard actions for trains, switches, lights etc using almost all Bluetooth operated LEGO parts. They've also added the new components from this set to the project.


So, what is final verdict?

The build is excellent. The instructions are clear, but still a challenge. You really need to stay focused, or there will be rebuilds to be done. The tests after each stage are very useful in that respect. For me, Stage 4 and 5 were a bit more boring, but that is only because I prefer to build structure and functions. Adding the little details are just not my favorite part. Not only in this set, but basically in every Technic set, so the set is not a fault here.
One issue that was a bit of a let-down, is the level of Technic in the functions. Besides the tracks and the rotation, there is very little gear-stuff involved. I love to build complicated gear boxes and long drive trains. For instance the 42043-1 and 42082-1 are my favorite builds. I would love for 1 motor to drive a shifter for extra functions, like in the 8043-1. In this build, this just felt short.

Functions and App
I'm pleasantly surprised by the app. That started by the fact it works flawlessly on my 3 year old low budget Huawei Android. I was already trying to arrange a higher end phone for this review, but that was not needed. Also the small screen was no issue.
The controls are good and intuitive. My almost 4 year old daughter had no problem figuring them out.
All functions work good. Besides the bucket opening and closing, everything operates smooth. The tracks get a good speed, especially compared with the 42055-1. Even on slippery surfaces like stone tiles, there is enough traction because of the weight of the model. Speaking of that: The model can be picked up easily by putting your hand underneath it.
There is just one thing that bothers me a bit, and I see that mentioned more often in Facebook groups etc: How long will this technology last? Everything is controlled by the app. None of the motors or hubs function without it (or third party apps). Co-incidentally I received a 8482-1 CyberMaster set from a friend while I was reviewing this set. I quickly learned that this set is only controllable through a PC. And that PC needs to run on Windows 95 or 98. Or with special software to trick the computer it's 20 years old. Luckily that same friend also had an old laptop that runs the software, otherwise I could have used the set only as a part pack. Right now, everyone has a smartphone or tablet that has Bluetooth and can run this app. But how about in 20 years? How will technology advance? Nobody knows, and that bugs me a bit.

This is a complaint I hear a lót! €449,- is a big load of money. Is this set worth it, even though it only has 50 parts more than the next biggest set 42082-1, priced at €249,-?
Well, there are some other factors than just the part count. Let me break it down for you:
• Electronic components: This set comes with 7 motors and 2 smart hubs. This is not done before in a Technic set. These are expensive components, and brand new. That raises the total a lot. I've checked the prices on BrickLink. Getting the PoweredUp elements loose will set you back €190,-. That leaves €260,- for the rest of the parts, which brings the price per part down to just 6,3 cents.
• Design: The 42082-1 is a generic crane. There is not an real life model for it, that will influence the design process. With the Liebherr, the model has to look like the real life thing. That complicates the design a lot, because there is les margin to fit in the functions. More design work = more time = more money.
• Parts: There are several new parts created just for this model (for now at least). These need to be designed, tested, mold created etc. The 42082-1 only had a few recolors.
• The app: There is an extensive app created for this set. They didn't take the easy road and just made some buttons to control it, there is an extensive control system, complete with programmable components etc.

But, is it worth it? I think the price is right for what you get. It is a great build, it looks and works great. But, €449,- is a lot of money. Normally, this set would fall far outside of my LEGO budget (or I couldn't buy anything else for a year). So I get that people are not happy with it. It's never fun when a great set is not within your reach. I have that at the moment with the new 75252-1 UCS Imperial Star Destroyer. This will definitely lower sales.

If it's in your budget: Go for it. If not for the model, it's a good way to get a lot of new motors and hubs, along with a load of parts.
If not: Hope for a good discount.

Disclaimer: This LEGO set was kindly provided for review by The LEGO Group. Anything said in this post is the opinion of the author and not The LEGO Group. Parts- and build photographs by Tobymac (© 2019 Rebrickable)


  • 5 hours ago axelts (144) MOC Designer
    This is a large and expensive model, interesting to build — but without an alternate build on the LEGO® site — and mostly fun to operate with a smartphone or tablet.

    Sadly, however, with this box LEGO® has abandoned its roots. Previously, any LEGO® block — no matter how old — could be used for anything one wanted to build. This box contains seven motors and two Bluetooth-controlled batteries (hubs) which seemingly can be used only in ways that the LEGO® Control+ app deems appropriate — and those are but two.

    The app loads controls for the truck (42099) or the excavator (42100) and begins to check if they are built correctly. If you select the wrong model you have to forcibly terminate the app and start all over!

    The app has tests to supervise the building process. Unfortunately, there are no helpful messages to explain that to test one motor you have to plug in the others for that battery, even if they are not yet part of the building experience — I’m still waiting for LEGO® support to explain that to me. Once you are all done building, the app is a slick controller for the model and that should keep your attention for a short while at least.

    If you buy this box you might want to search your phone or tablet’s app store. The iOS app store has an app "Boost Remote" which provides access to one of these battery boxes and its motors...
  • 1 week, 5 days ago BarneyGeroellheimer (101)
    Thanks for the nice review! I just got mine yesterday and can't wait finishing the build. I totally agree on how the price may be achieved. I've read somewhere that people had trouble when testing the functions during the building process. Probably a problem when not all motors are linked to the hub?
    • Yes, the hub will only connect to the app when all motors are connected correctly. After stage 2, only 1 XL-motor is connected yet to the upper hub. In my beta release of the app, he wouldn't connect until I attached the other 3 L-motors as well, that come later in the build. I haven't tested the official release yet.
      • 1 week, 3 days ago BarneyGeroellheimer (101)
        In the official version, this issue is still there. I just skipped the test and repeated it when all motors had been connected. Thanks for replying!
  • 1 week, 5 days ago psmyth (6K)
    thanks for the great review...well worth reading!!
  • 1 week, 6 days ago Brickfan (6K) MOC Designer
    Excellent review TobyMac :)
    I think I will for now just buy the XL linear actuators, when I find someone selling them. Currently they are not listed on bricklink.
    Maybe my wife might let me buy one next year, or if I can find a really good price etc.... Loved the OCD comment :) I expect my wife would have noticed that too :)
    Nice also to see that BuWizz works with the hubs. This should hence get around the problem of FOL's wanting to use the hubs and motors in their own MOCS?? As much as I would like both 42100 and some buWizzes, the prices are certainly a hinderance at the moment.
  • 1 week, 6 days ago thisguyiknow (63)
    GREAT review. Thanks! What type(s) of batteries do I need to power this and how many?
    • Each hub uses 6 AA batteries.
    • 1 week, 6 days ago Brickfan (6K) MOC Designer
      Looking at the picture of the battery holder, and also having watched Sariel's review, I suspect it takes 6 batteries, per hub, AA size, but TobyMac will no doubt give a definitive answer.
      I was under the mistaken impression that these hubs would be powered by LiPo batteries much like the trains are, and the buWizz. This is a big disappointment to me, LiPo surely must be better for the environment? That is one of the more appealing aspects of BuWizz.....Not having to buy lots of batteries, and then dispose of them in a manner that does not damage the environment.

      Hmm, your answer arrived after I posted mine, even though it was apparently posted 16 minutes earlier! :)
  • 1 week, 6 days ago AveN (219)
    Nice Review. I'll think about this Set, but it's no must buy for me, so I can wait for a discount ;) I'll expect no B-Model and I'd also like to monitor the development of the app and alternatives.
  • 1 week, 6 days ago jokey02 (5K) MOC Designer
    Thank you for this clear review. I ordered the set this morning but it will send Friday, so I can't wait to get my hands on it
  • 1 week, 6 days ago BertZelf (3K) MOC Designer
    Thanks Toby.
    Good to read your review. 
    Maybe you can use a hamster for a next review to have a comparison for size ;-) 
    You started with 
    will I be proven to be a whiner?

    No, you're a winner.

    And I agree that each Technic model needs a minifig driver (m/v)

    Thanks again,
  • 1 week, 6 days ago HRU Bricks (2K) MOC Designer
    Nice review.
    It is an experience set bit worth it.  If you are in the fence wait for a sale.  
    The build experience for me was fantastic, the sets movements are smooth. You are paying more due to the new hubs and motors, if they were not there it would be around the price of the 42055
  • 1 week, 6 days ago nkende (3K) MOC Designer
    Great review! Thank you for making it!
    Does anyone know why some parts are marked "color error" in the inventory of this set? (eg. 40918, 46835)
    • These are new parts. I loaded the inventory this morning, so the site doesn't 'know' yet that these parts are in use. The errors will disappear within 24 hours.
      • 1 week, 6 days ago nkende (3K) MOC Designer
        Thank you :)
  • 1 week, 6 days ago TurboRatRods (79K) MOC Designer PRO
    Thanks for doing this review.  VERY informative and appreciated.  I do have one question - Are all the Pneumatic parts just used to simulate hydraulics or do they actually do something?
to your account to add or reply to comments.