Construction Vehicles & LEGO Technic go together like bread & butter or PB&J, so an excavator should be pretty darn good in Technic, shouldn’t it? Well, this certainly isn’t the first Technic excavator & it certainly won’t be the last.

The build for this set is anything but ordinary because most any LEGO set would start out with the body of the vehicle but not this one, this one starts with the whole bucket arm & some of the body core. After the arm you start the body, but the set makes another left turn in Bag 3 where they jump to the treads before finishing the body however there is some logic behind that decision as the pins that attach the tread assembly to the body would be covered up if you finished the body before adding the treads so while strange, it does make sense.

The finished model is a yellow, black & grey vehicle with a large arm sticking out, exactly what you’d expect & that’s fine, no need for surprises. All the details in this set are either built up or stickers but what is stickered is fine because it’s details like the control panel or the warning symbols by the bucket arm although the taillights are stickers & that does suck but options are very limited. There are two stickers that are applied that are for our sake & those are stickers placed next to the two knobs for moving the arm & that is always a nice consideration. Unfortunately, this does suffer from an issue that plagues any Technic set & that is the massive amount of exposed Technic Pins & Axles & while the colours are used to differentiate the amount of friction in Pins, it does detract from the visual appeal of a set massively.

For play features, there actually isn’t all that many but there aren’t all that many features you could include. You do get working treads that are mounted to a large Technic two-piece turntable to allow 360° rotation but there is not a “cheater wheel” built-in & while that is a disappointment, there also is no room to attach it so on softer surfaces it works well but on a hard surface like a table, it’s just going to slide along.

Of course, the obvious feature is the fully functional boom arm, how it works is that you use the two knobs, the one on the side of the vehicle moves the linear actuator on the top of the arm which in turn moves the front of the arm where the bucket is attached meanwhile the knob on the back of the vehicle will move the other actuator which will move the base of the arm. This feature is actually very fun & is something that you need to see as you’ll see how smooth & fluid the movement is & that is very nice to watch.

Now, we do need something to scoop up with the arm & LEGO kindly give us 20 pieces of “debris” & by “debris” I mean 20 1x2 beams with a Pin & Axle hole, use your imagination a bit, & you also get four very simple traffic cones to put around & while simple they are nice little pieces that use only three pieces per cone, they simply are just perfect.

Now, how well does the arm scoop up the debris? Not great, the bucket just can’t pick up the debris without help, bummer.

Overall, this is a fun little construction vehicle set & while the features don’t work all that great, it still looks nice & with a bit of help you can get the play features to work. Although that isn’t all this set can do as there is a B-Model & to TL; DR the B-Model, the B-Model could easily be a primary model, it’s that good.

Some time ago I started to write a comparison of technic excavator models. These are the ones I have done:

• 8851
• 8837
• 8294
• 42006
• 42053
• 42121 (this set)

You'll notice that big sets (8043, 42055, 42100) and small ones (8419, 8047) are missing. The mid size range offers sufficient functions that can be compared in-between the sets.

Description

Of the technic excavator that I have reviewed so far this is the smallest model.

The english name of the set well describes its shape: the smaller cabin, the massive boom and the solid superstructure support the impression of a heavy machinery. The german name "hydraulic excavator" plainly does not suit this model.

Model

Main colours are yellow and black with dark grey (on the tracks) as a supporting third. The boom appears rather big compared to the rest. Especially when looking from the back of the excavator. It is 3M (or 3L) wide - the same as much bigger sets 8294. Due to usage of many panels and system bricks (curved and flat tiles) it has a more defined look as many previous machines.

(content of the box - tray is 40 x 60 cm²)

The choice of using black colour for the boom supports the heavy-duty look.
There have been complaints about the "sand blasted" transparent panel that is used as window for the cabin. I do not mind that.

Functions

The excavator runs on small tracks that have already been used for 856 and first excavator (8851). 16 tooth gears are just sufficient as main rollers. The track links are sliding over the beams with only two more 8tooth gears as support.

The superstructure can rotate freely with respect to the undercarriage.

The boom is operated by two small linear actuators: One the raise and lover the whole arm. The second one bends the boom and, because of some linkage by lever also tilts the shovel. What I really like is the position of the two knob wheels that control the linear actuators: one is at the back (bending), the second (up/down) at the back. Therefore both can easily be operated simultaneously even with big (adult) hands.

Surprisingly, the designer did not make use of the full length of the upper actuator. It does not contract fully, about 1M remains.

Comparison

This is a small technic excavator that would fit into a minifig town. Thus, scale is similar to 42055 and 42100 while the other models are matching with size of technic figures.

There is not much inside the superstructure. The linear actuators are driven (almost) directly, without using any gearbox or transmission.

More picture at my Brickshelf folder.