"After building several Star Wars, Disney, and other assorted Technic kits, this has been my favorite. My previous Technics build was the Lego 42100 Liebherr excavator. Comprised of 4,100 pieces and filled with motors it was a multi-day build. It’s big and expensive. However, with enthusiasm I have declared that the 42108 mobile crane coming in at just under $100 is now, without doubt, my favorite Lego build.
I found myself cheering on the designer(s) of this build at almost every step. It is filled with creative and well-designed features. The way the crane arm extends is simple but wonderful. But my favorite feature, by far, of any Lego innovation is the way the wheels on this mobile crane move. As I was marveling at the turning mechanism, how the front and rear wheels move opposite each other, I was impressed. I didn’t know how this was going to play out in the final form and as I got caught up in the build I forgot about this mechanism.
When I reached the end of the build and was installing the eight giant tires I wondered how this crane was to be steered? Had I looked at the final instruction page I would have known but I used my iPad instead of the instruction booklet so I never turned the page. I took the wheels in hand and carefully turned one set and then I saw it. I was stunned! The large rotating beacons on top of the crane cab turned in sync. Essentially, you turn either of the beacons to make the wheels turn. That was freaking amazing! Even though I should have seen that coming it never occurred to me this would happen. I am beyond impressed. There are three knobs that operate the crane boom. One raises the boom, one extends it, and one operates the cable. Even the outrigger stabilizers have well-designed mechanisms to deploy.
Lego sets can be expensive. Some just sit there and some move in different ways. The trains are a fun build and so are the cars. But for the value and amazement of what the gears and various mechanisms do, this kit is by far the best value for the money. Sure, there’s no motors or automation and iPhone app. This is pure hands-on play with no automation. The design of this crane deserves some kind of Lego build award.
Bravo! to the person or persons who designed this incredible kit."