Thursday, July 8, 2010

TBs TechReview 10 – 8043, Motorized Excavator

Set reference: 8043
Set name: Motorized Excavator
Release date: 2010.Jul ( / 2010.Aug (Retail market)

Number of parts: 1123 (some spare parts added into the box)

Model under review:
Main model
Weight: 1.285g (without batteries and remote)
Approximate set dimensions:
- 18,0cm (7.1")
- 39,5cm (15.6") fully retracted digging arm
- 44,0cm (17.3") extended/raised digging arm and bucket
- 21,0cm (8.3") extended/lowered digging arm and bucket
- 38,5cm (15.2") fully retracted digging arm
- 52,0cm (20.5") extended/raised digging arm and bucket
- 63,0cm (24.8") extended/lowered digging arm and bucket
Underground reach limit
- 7,0cm (2.8")
Approximate box dimensions:
Height - 9,0cm (3.5")
Width - 57,5cm (22.6")
Length - 47,5cm (18.7")

Stickers: Yes
Building instructions: 3 booklets (84, 84 and 48 pages), with 99 major building steps.
B-model: Tracked Loader (instructions available for online download only)

Recommended for ages: 12 - 16
Building difficulty level: High
Estimated building time: 4 - 6 hours
From proficient to average builders. Of course it could last for days if your are not used to build with LEGO Technic...

Price range: 139,99GBP
Price per part: -

Inventory (Bricklink): Link
Inventory (Peeron): Link
Other user reviews (Brickset): Link

TBs made its first review for a 2H2010 LEGO Technic set. And which better set to review, then the most waited Technic set of the year?
The large scale and fully motorized Excavator. Epic!

The package and contents

Lets start with the usal photos from the box.
The main model and respective functions at the front. Please notice the box artwork differs slightly depending whether you take the US or the European version.

On the backside you will find the image from the B-model (a motorized tracked front-loader) and the indication that the respective instructions will be available online only, as usual.

The box keeps the traditional design from the large Technic sets boxes, with two seals at the bottom-front and a flip-up cover. You must rip or cut the side perforated ears, despite I managed to take everything out of mine, without damaging the box...
The cover flips-up in two levels, where the first just unveils extra images about the main model and the six main functions featured by the model.

As for the contents, you may also see them below.
A total of 9 not numbered bags, with the parts, plus the large bucket and the 4 PF motors, the battery box and 2 IR remotes, each in its individual bag. As usual some bags have other smaller bags inside for the tiny parts, like Technic pins and so.

The box also includes the instructions booklets and the sticker sheet.
It is usual to hear complains about damaged manuals or sticker sheet, when you open the box. An old problem with easy solutions that LEGO seems not interested in solving, as the involved costs may not worth the number of reported cases through the Customer Service. However this time I got something I've heard reported before but though to be extremely unlikely. One of the stickers peeled-off from the sticker sheet and arrived attached at the cover from one of the manuals. Fortunately it was not really damaged and because the manual are like glossy, it was quite easy to recover it. Otherwise the excellent LEGO Customer Service, was just at the distance of a call...

Yeah... I've put the slippery sticker, back in its place first...

The building instructions are divided in three books for the main model and they are nearly A4 sized. They have respectively 84, 84 and 48 pages each and include 99 major building steps for the main model.
I've found no errors in these, which does'nt mean there aren't any. It wouldn't be the first time I've build right, with small mistakes in the instructions...
At the end of the third book you will find an inventory of included parts into this set (spares not accounted), which is now also a standard and could be very useful.
Lets take a look, as I think they are not yet available anywhere else.

All this, for...
...well, expected retail prices will differ across countries as usual. For the moment the unique official price available from is 139,99GBP for the UK, but my expectation is that it should not go too far from the 165-170€ range, at most of the other European countries.
LEGO prices have been increasing, this is not new! However and despite an high price-per-part we must realize this is a set which includes a good bunch of  PF elements (4x M-motors, 2x IR Remotes, 2x IR Receivers and one Battery Box) only comparable to the 8275 Bulldozer in the recent years, when the PF system was first introduced to the market.

Next step consisted to open the bags, dispose the parts over the table, and start to build.

The new parts

Despite some parts in new colors (black sprockets, new panels never released in yellow before), this is not a set plenty of new parts.
It just includes the new connector shown in the photo below, which is not much different from an extension of the previously available 48496 with a different connection interface and thus a bit more versatile.

It looks to be a very useful part for transmissions where the rotating axle changes to a perpendicular and used 6 times within this set.

The part assortment

A set with just a few studed or SYSTEM parts and another yellow machine. However I must say the color chosen is a perfect fit for the model itself (despite IMHO the orange could be also an excellent alternative... ).

It includes an high number of gears (71 in total) and specially a set of less common parts like '16 tooth with clutch' (6542) gears, driving rings (6539) and driving ring extensions (32187) heavily used in gearboxes, thus a good source for those in the need of them.
But it is also a good source for those needing a variety of other specialized parts like: panels, connectors, u-joints, treads, frames, linear actuators, PF elements, etc...

With this set, color coding for parts like: gears, pins and axles continues as a trend of the actual Technic theme. Even the 'axle 3 with stud' (6587) kept the recently adopted Dark Tan color coding.

I'm also relative well surprised, with the number of times that recently release parts (2009-2010) are consistently being used with new sets (26x 87083, axle 4 with stop; 10x 87082, pin long with friction and center pin hole; new frames and panels, etc...).
It suggests these were parts really needed, to fill a gap into the LEGO Technic building system.

The set

Well... I'm quite suspicious to speak as many of you should know this is simply my favorite type of machine, that for long I'd liked to see released as a LEGO Technic official flagship, in a large scale and fully remote controlled.
A wish come true!

The model features 6 motorized main functions (3 for the main structure and another 3 for the arm), and one supplementary motorized function:
  • Drive forward/backward
  • Turn left/right
  • Slewing superstructure
  • Articulated boom
  • Articulated dipper
  • Articulated bucket
  • Remote controlled selection for the set of working functions

LEGO Technic designers have used a smart setup with 4 motors, in a 2x3 + 1 functions arrangement.
One motor drives a switch-box which then makes the remaining motors to alternate simultaneously between two sets of three functions. The three functions from the excavator structure or the three functions from the arm.

This was the most discussed secret, when the first images started to appear. Soon advanced as the most probable hypothesis and later unveiled/confirmed when the first review of the model popped-up.

All together resulted into a fantastic set, but lets see it more in detail ahead.

Building experience

As usual for these kind of models, the building process starts with the drivetrain.
It is a symmetrical structure, simultaneously strong an light as you may see from the on the right side (taken after the model was complete).

A nice feature for a model with this scale, could have been the usage of independent pendular bogies, for the inner wheels supporting the tracks. It would add realism when crossing small obstacles or terrain elevations.
However the the M-motors used to power the drivetrain maybe already stretched too much, to be thinking about obstacles... and someone commented here that real Excavators don't work like that.

Well... after one hour of fun, it was going like this.

Having been introduced for the first time into an official model (8258) the last year, it is the second time in a row that Clutch Gears and Transmission Driving Ring elements were used to pass two motions through a turntable. You need it to achieve the ability to continuously rotate the superstructure, having all the motors placed in the upper part but still driving functions in the drivetrain (making the two tracks move in this case).

The photos below show how much it looks like what Jennifer Clark did in its Excavator [1]. Could I have finished this review, without mention such mythic Excavator...

The build instructions proceed with the superstructure (or the turret), where core of this model resides. It includes a sophisticated switchbox which controls the 2x3 functions switching as mentioned above, but it is where the four PF M-motors also fit, the two IR Receivers, the battery box and all the built-in cables required to operate everything.
It is an extremely compact LEGO Technic masterpiece, occupying the least possible space and where at a first glance, every single stud is occupied with something useful.

This is not an easy mechanism to understand in words or from this kind of photos. You must try it and play a bit (preferably before attaching other parts and get the model complete), to fully understand how it works.
Basically there is a set of driving rings (3 in the present case) which are simultaneously actuated by a common shaft, to switch among the output axles which are going to drive the selected set of functions working at each time.

This is where I found something strange. At step 35, page 79 (still in the first booklet), there is a shaft with a knob wheel used to turn the changeover catches and move all the driving rings on the switchbox from one side to the other. Surprisingly the shaft attaches to the frame with an axle/pin with friction, whereas the frictionless version might be expected.

Ahead as we will see, this made me wonder even more, but it turned to be not doing any difference.
Once it looks to have really no functional impact in this case, despite a part being subject to extra wear, I tried to find an explanation for its use here. Even thought that maybe for inventory purposes TLG was trying to avoid the introduction of an extra element being used just once in this model (assuming it makes sense such thinking...). But that's not the case either, once one (just one) frictionless axle/pin is used in the whole model, but not here...
There might be reasons of course, which are behind my knowledge on how to build models, and make parts selection.

Now that's when we start to attach the superstructure to the drive train. At this point it is still pending unbalanced to the rear side and causing some stress. But it will become quite well balanced some steps ahead, once we start to attach the digging arm.
At this point the two parallel Linear Actuators used to sustain and lift the boom, are already attached to the superstructure. The recently made available idle gears are also used in this setup, which makes it easier to drive both Linear Actuators, given the high forces being applied to this articulation supporting the whole digging arm weight. These idle gears should have been one of the most useful parts released in the recent past.

By the middle of the second instructions booklet, we start assembling the digging arm.
It is very well designed and allows for a quite realistic range of movements and reach. We know from previous pictures, this was a part of the model that suffered changes till a late design phase of this model, but the result achieved was very good as we will see when talking about the model's playability.

The arm width may look a bit large for the model scale, but that's needed to make the two drive shafts traveling across the arm and drive both the Linear Actuators used to move the dipper and the bucket.
Notice that unlike the solution used at the former 8294 (The red excavator), where the bucket moved coupled with the dipper arm, here in this model all the arm movements are fully independent, thus a lot more realistic and funny to play.

Quite noticeable and unexpected is the usage of the studless Technic frames as central parts of the digging arm, making it to develop around and feeding the two driving shafts through the middle.

The bucket used in this model looks somehow inappropriate for the scale, as it is quite wide (in fact it is a shovel instead of a bucket as it should be). However we must acknowledge that unless TLG decided for a new mold, there was no other bucket available that would make a better fit in this model.
So the excavator operator will need to drive with the huge bucket blinding him, when the arm rests in its fully retracted position.
On the other way, if the B-model planned was always a Loader, then the only part which could be used in both models is the large shovel.

The two photos below shows how the excavator looks like, just before adding most of the fairing panels all around and after it.

As we may see in the photo at the right side, there is a double PF IR Remote, to control the six multiplexed functions, via the four motors used.
The three levers on the left operate the three selected functions, and the rightmost one (marked red) is used to actuate the switch box and select the set of functions available at each time. There is also a red lever on the turret which moves according to the selected functions for visual indication or reference. It is also possible to actuate it manually, despite the resistance applied by the motor where it is attached.

Nice look on the back side, and smooth surfaces applied.

The way the battery box is attached into the model is quite smart and makes it very easy to replace batteries.
There is a pin in the bottom to help fixing it. Once wired and put in place there is a long axle holding the battery box at one side which is locked when the exhaust pipe went over, and a small crank on the other side just for helping to hold it in place.

It took me about 4h30m to finish it all! Well... that was what I thought...

Next I almost went crazy, trying to understand why the switching function was not working properly. The switching box was persistently not moving, almost always when the respective red lever on the remote was actuated. Only a few times and if the switching box was manually left in its middle position, it was possible to complete the selection remotely, in one direction.
That's when I remembered first about the suspect friction pin mentioned above... But after having replaced it, I was to conclude this was not the guilty guy.
A few other experiments changing the receiver ports or direct power applied to the motor, all leaded into frustration.
Still no idea about what may have went wrong, since everything was looking properly assembled and it was also not that complex after all.
Batteries changed... Suspicion if the mechanism would not work properly with 7,2V rechargeable batteries instead of stronger 9V non-rechargeable ones, but no way!
Not even the motor showed any evidence of start and stall once powered, which made me wonder even more, despite the force required to manually make the gears to move.

It was only when I decided to disassemble a bit further and tried to exchange the position of two motors, that it suddenly started to work perfectly.
Unless there is some unlikely and small detail that I didn't figure out, like the one that originated an errata for the building instructions of the 8275 Bulldozer, I suspect of an under-performant (defective) PF M-motor, supplied with my unit, which however works pretty well for the less demanding mechanical functions.

And finally these are the leftovers, if I didn't miss any of them in the middle of the building steps...

Functionality and playability

I wanted to start writing this review, just after finishing to build this model and have solved the initial problems. However the appeal was stronger than me, and didn't resist to play a long time with the excavator, together with my 3yo son...
And that's it! This is a model plenty of functionality and even more playability, that will delight youngsters and those grown-up.

It is a large size model, but not too large, and very compact at the same time. Specially if we think about the minimal space used to accommodate all the required elements to perform the intended functions.
All the functions were extremely well designed and work without flaws, which is not always the case for the large Technic flagships. Large models are prone to certain type of failures, and this has none!

First you will need 6 AAs for the battery box and then another 6 batteries AAA, for the two IR remotes.

Despite I would advise to use fresh and non-rechargeable batteries to take full advantage of this models functionalities over any surface, it still works pretty well with rechargeable 7,2V accumulators.
Even it is possible to run three functions simultaneously, without problems at normal conditions, which guarantees by itself a great playability for this model. Specially if we are playing with the digging arm.

The drivetrain and  the solution to pass two motions (one to control each track) through the turnable, was done in such way that they do not interfere with each other. Well... almost! Only occasionally we will see one track to advance one tread, while the superstructure is turning.
The drivetrain moves relative slowly but still at an adequate speed if we think how the real excavators work. Comparatively the superstructure rotation is quite faster, which is also in accordance to the way such machines work in real life.

Probably the drivetrain would demand a bit more power, but it may lead the need of using two XL-motors.
That would completely change this model: space, gear relations to the digging arm and inability to use all the functions simultaneously due to PF power constraints.
After all it would be more like a drawback then a positive choice. Thus I'm 100% with the options taken by the designers team.

Used gear ratios in the way to the drivetrain and to slew the superstructure, also produce a nice visual effect when the tracks are driven in opposite directions making the excavator to turn in place at one direction and the superstructure is rotated in the opposite direction. In the end we can make the drive train to rotate in place, while the superstructure looks standing still.

The digging arm was the most critical part in this model, to make its operation to look realistic. There a lot of details to pay attention and to try to reproduce in the perfection. The static and dynamic angles, the extension, height and deep reach ranges. The model seemed to have suffered several improvement steps during the design process till a late phase, as mentioned earlier, but the final result is really good and quite realistic given the wide operating arm range achieved.
Lets see now some photos which show exactly how far it goes.

Fully extended / Raised digging arm

Fully extended / Lowered digging arm (reaching an impressive 63cm length)

Lowered boom / Fully retracted dipper and bucket

Fully retracted digging arm and bucket
Underground reach limit (up to 7cm below the ground surface)

Acrobatic skills...

Operating arm speed is also another very acceptable characteristic of this model. Well done!

Another thing you will notice is a more than evident digging arm twist, when you are moving the bucket or the dipper and suddenly the respective Linear Actuator reaches one of its course limits. However this a normal consequence from the abrupt deceleration and there is nothing you can do to avoid it, unless to play it very carefully.

And now a video to show this beauty beast, in action... .

It is not the type of video I was expecting to produce, but it turned out the the Excavator performance at outdoor/off-road terrain, is not exactly what I was anticipating. Lets say that grass and gears on the drivetrain, are not best friends...

I think the only thing I'd like to see released now, is a new Excavator with pneumatics controlled with PF miniature electro-valves... And a new supercar, of course!


The 2nd model proposed for this set, is a Tracked Loader.
Somehow it has some similarities to the landmark 8275 (Bulldozer), but some significant advantages in terms of playability:
  • Can use the 4 motors simultaneously. Something that was not possible with one battery box and two XL-motors, plus two M-motors, according to the PF specifications.
  • The Loader uses 4 Linear Actuators to move the bucket, which were not yet available, when the Bulldozer was released.

Furthermore we can say that the 8043 seems have a much better or more complete B-model, than what the 8275 had at its time.

Lets see if I manage to find the mood and the time... to review this one, next time here at TBs .

Final thoughts

Rarely I use to apply the stickers into my LEGO sets, but in the present case I was not able to resist.
The model turns really awesome when they get applied.

Maybe you already know from previous posts, this is a model designed by Anders Gaasedal.
But if it was not the case, there will rest no doubt about it, once you take a close look to this model stikers.
It has been a tradition for already some time, that each designer of a set leaves a personal mark with his creation, like the vehicles registration plates, etc...
In the present case there are two of them. The "AG" suffix appended to the model number (8043AG) at one sticker, but also Anders' nickname (Goose Valley) at another sticker on the left/front side.

A positive note about the stickers applied to this model - No STAMP (STicker Accross Multiple Parts).

Now just a small MOD you may like to do, if you prefer more fairing and less gears at sight (good hint, Tito ).
One panel, four pins, et voilá!...

But of course there is a lot of other things you can change as well. This was just the most easy and obvious to do.

Finally the only thing I've missed in this model...

Who knows, now that we are getting close to the LEGO Technic theme 35th anniversary, that if TLG won't decide to give us back some nuggets from the old times. Just dropping the idea...

The Ratings

This time I have not even the minor doubt!
This set goes directly to the top of my list of preferred Technic sets ever released. Defeating the 8455 to an honorable 2nd place. They are not that different after all...

   as set value for money
   for innovation
   for set design
   for functionality and playability
   for quality

Overall rate: Must have!  

Definitely a must buy, at any price tag. If there were already no other options to buy at a fair price. But of course beeing a new release, there will be plenty of chances to find at good deal prices, sooner or later.


Bricks and Bobs said...

You are so lucky being able to try this out first hand! having followed the hype earlier in the year, I wasn't sure whether this would be a worthwhile set. Your review certainly makes me feel it is. It seems quite a complex build which is exactly what I look for in potential LEGO sets :-)

PS) Looking forward to the video

legocn said...

That's really cool

Junkstyle Gio said...

Reviews keep poring in. This is another great one!
Blackbird made an great review at Eurobricks.
Sariel made a videoreview available at youtube.

B-model buildinginstructions are available at (Technic product-pages.)

sunsky said...

I think the new part will be a good piece for front(steered) hub of 4WD or AWD vehicle.

Anonymous said...

Sariel, Blakbird, and you. Hum, you get it form TLG as you are a Lego blogger, right ? :D

I saw the B-model building instructions this morning. I think I will build these B-models this week end.

Besides, nice review, of course. :)


TechnicBRICKs said...

Does it matter where we did we get it from, if you got it first? ;D

Well, but I think people at LEGO, prefer to get reviews from the sets, when people can already buy them. Even if UK is the only chance at the moment. :P

Junkstyle Gio said...

Lego Technic 's 25th anniversary? The first technic(al) sets are from 1977. So this year it would have been the 33rd year..
Never the less. I'm getting old...

TechnicBRICKs said...

Oops... miscalculation... :(
I'll put 35th then. ;)

Anonymous said...

"Does it matter where we did we get it from, if you got it first? ;D"

That is not what I asked.
Well, anyway I know the answer. :D


thirdwigg said...

Out of curiosity, what are your top Five greatest Technic sets of all time? You mention 8455, what are your others?

TechnicBRICKs said...

Its hard to list and order 5 of them.
It would be easier if I would list about 20 without any specific order.

But let me try...

Top 3 in playability:
- 8043
- 8455
- 8479

and a couple of Supercars
- 8880
- 8480

There are several other really great flagships, but some functional flaws would prevent me to include them in the toplist.
In my perspective, to be in the top it needs to work perfectly always!

Efferman said...

Quote:A nice feature for a model with this scale, could have been the usage of independent pendular bogies, for the inner wheels supporting the tracks. It would add realism when crossing small obstacles or terrain elevations
End of Quote
In real world, excavators have no independent suspension. they are too slow to need one. The lego excavator is perfect realistc.

TechnicBRICKs said...


didn't know about that. Thanks!

Thought it would help to face some terrain irregularities and improve traction.

thirdwigg said...

Thanks for your response. I agree with 8880 and 8455. I was surprised to see 8479, though I have not spent too much time with it. Maybe some time you should do a post of the Greatest 20 sets. Or the 33 best for the 33rd anniversary.

TechnicBRICKs said...


Yes, I knew I'd surprise you. :)
Each set at its time!

8479 was also a surprise for me. I was not expecting too much from it, till the day I played with it.
Maybe we can compare it with the Control Centre II. But it is unique in many aspects!

Parax said...

Lol @ "Please notice the box artwork differs slightly" Yes, no signature!

I got this last weekend but have been away for several days! having built it the other night all I can say its great! its certainly in my top 5 sets!

If you are near Manchester UK this weekend pop in to MOSI to see it on show.

Anonymous said...

This really is the best set I own, full stop. I'm glad we in the UK finally got something in terms of an advantage from TLG, in that we got it first. I got it and built it on Monday after ordering it the first day it was available.

Also, great review of an excellent set :)

TechnicBRICKs said...


that was not what I meant.
But you are a good observer! ;)

blakbird said...

I noticed the same thing about the friction pins on the mechanism for the function switching. In fact, both gear axles for this function use friction pins. There are plenty of other spots in the model which use non-friction pins, so I assume this was intentional. It is probably to help hold the switcher in place during other vibrations of the model.

By the way, I assume you mean for the weight to be in kg, not grams.

TechnicBRICKs said...


it is grams.
That's what happen when ones (EU) use dot for the thousand separator and others (US) use the comma.
The opposite way for the decimal separator.

Note that I've also used different decimal separators for cm and inches...

It is hard to make it perfectly readable all over the world...

TechnicBRICKs said...

It took a bit longer then what I was expecting, but the video was finally added to the post.

It is not the type of video I was expecting to produce, but it turned out the the Excavator performance at outdoor/off-road terrain, is not exactly what I was anticipating. Lets say that grass and gears on the drivetrain, are not best friends...

Anonymous said...

When the heck is it going to be available in the USA? I want it bad.

TechnicBRICKs said...

Guess it will happen only in August.

UK might have had an early launch in Juy, for some marketing decision.

Anonymous said...

Actually we got it released today in the USA, 15 Jul 2010, so the UK'ers are not the only ones who are having fun now. It isn't listed on the US S@H website yet, but Toys R Us has it plus the 8053 Crane and the 8052 Container Truck. Picked up all 3 today and they are on the US TRU website too. Was a bit premature in posting that question last evening, checked the TRU website this morning and to my surprise there they all were, and 1 call to the closest TRU retail store confirmed all 3 were available. The 8051 Motorbike is there too, but that one seems rather expensive for so little, the 8420 from 2005 was better.

Daniel said...

Hello, I'm from México. It's kind of hard for me to get technic sets over here, which makes getting this great set for me a really epic task. After looking for many options I decided to ask a friend who lives in England to buy the 8043 for me, this is whi I need to know something:
Do yo know if it's already available on stores in the UK?...Or Can it only be accquired directly at the lego website? thanks.

(sorry for my english)

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