LEGO Technic Excavator Construction Toy 42055

Product Information

Having now built it, I can confirm that it is indeed an impressive machine, but it's really pushing the limits of what is possible with the Technic system and one motor...

You can also see in this picture the three axles that transfer power from the upper part of the machine to the lower part. They are connected using 'slip axles' which means it is easy to disconnect them for testing purposes.It's a long satisfying build and the finished model looks great, but how does it operate? Unfortunately this is where it's a bit of a let down. The 1x1s often just sit on the agitating plate and sometimes never exit. This is because (a) they are not spherical and (b) the plate is not completely smooth, so depending on how they land, they don't always roll down it. The plate's up and down movement is not sufficient to encourage them to move! Unlike the other three large Technic sets released this summer, this one is not based on a real-life machine. Its design is certainly influenced by real BWEs but it looks nothing like any that I have been able to find pictures of. Take a look at some images yourself and see if you can fine one. It's somewhat front-heavy so there is a bit of a tilt on the body which results in the vertical frame not being exactly vertical. It doesn't seem to interfere with operation though. It's entirely possible that I was not careful enough during construction and mounted gears or connectors too tightly thus causing too much friction but if I -- a Technic veteran with 20+ years experience -- can do that, what hope do kids have of building it any better?

This is definitely a set that benefits from a video review so I encourage you to watch Sariel's. You can skip past the unboxing and construction to 17m 30s to see the machine in operation. Step 8 completes the model with the cabin, railing and other small stuff. The cabin is a little too small for a minifigure. Occasionally, 1x1s will exit with the 2x2s. It seems to happen if they are carried along inside on top of multiple 2x2s or land sideways on the three axles. If that happens they invariably drop into the depths of the mechanism rather than travel along the belt because it's not been designed to stop them doing so. Fill out an Inventory Change Request ( ?) [ Show Inv Item IDs ] if you found an error in this inventory. The driveline for driving, turning and the small conveyer belt are also connected with these parts. Here it’s more obvious. The parts don’t hold tight to the axle but can slide. This allowing some wiggleroom when lowering and raising the big arm.

Video review

Following on from that, the rear end of the digging arm is constructed which includes the control panel/gear box. Here you can see the innards before they are hidden by the top panel. It's a great set to build and to behold but its operation lets it down a bit. Also, its size -- while impressive -- will make it difficult for many people, myself included, to display. It's not something you could take into work and put on your desk, for example! After 225 steps and about 3.5 hours of building the chassis and lower part of the body are complete. A third conveyer sits at the bottom of the input chute. It moves much slower than the output belts.