Railroad Crane
Model of a generic railroad crane. Features remotely controlled rotation, boom elevation and extension, winch, manually deployed outriggers and a modded locomotive, all controlled using a PS4 pad.
Datasheet:
Completion date: 06/04/2017
Power: electric (Power Functions + SBricks)
Motors: 4 x PF M
I have only recently discovered existence of the railroad cranes: that is, cranes built on train cars and being pulled as part of a train. Such cranes come in many types and variants, but they have all seemed immensely playable to me and I wanted to make a crane at Lego Trains scale that would be fully remote-controlled. This was an obvious challenge due to a small scale, but then I’ve learned that Lego Trains MOCs are typically 8 studs wide (unlike sets, which are mostly 6 studs wide). With that kind of space available, I was able to fit the whole crane with 4 motors, one SBrick and one 8878 battery into a single train car.
The crane had a chassis with a central turntable rotated by a single PF M motor below it, and with four folding outriggers that had to be deployed manually. The superstructure housed 3 more PF M motors, one for elevating the boom (using one small linear actuator), another for extending the boom (using rack pieces and worm gear from the 42062 Container Yard set), and a third one driving the winch using a worm gear. All the motors, including the one in the chassis, were connected to a single SBrick in the superstructure. Thanks to the SBrickController app, I was able to use a PS4 gaming pad to control the crane, as well as the locomotive pulling it, which was a modded 60052 Cargo Train set’s locomotive with another SBrick in it.
The crane worked pretty well and had an outstanding lift capacity for its size, being almost able to lift an entire locomotive. This was particularly impressive considering that there was not a single beam in the superstructure, it was all built with bricks and plates that were bound to come apart under too much stress. The boom was rather short, partially because of the fixed length of the 42062 set’s rack pieces, and partially because a longer boom would protrude in front of the crane’s chassis and thus it would make going around corners difficult. The outriggers were necessary to allow the crane to rotate, as the superstructure was pretty heavy, with most of its weight at the back. Because the outriggers had smooth tips, it was possible to move the train forward and backward even with outriggers deployed.
My focus was to make the crane as playable as possible, at the cost of its look. It was obviously ugly and looked very simple, not much more than a crude box. This was because its inside was packed very tightly, leaving no room for fancy details, and also because the superstructure was held together by its exterior, which would be inevitably weakened if small, complex details were built into it. The best I could do was to make the crane’s colors match those of the locomotive pulling it – but it was still quite an eyesore.
In addition to the crane and the locomotive, I have built a tiny yellow truck, which was fully motorized and remote-controlled, too. The goal to building it was the discovery that unlike the Lego PF IR receivers, SBricks can be powered from old small 9V Lego battery boxes. This allowed me to use one 71427 motor for drive and one Micromotor for steering. The resulting truck was very ugly and crude but could drive and steer pretty well. In fact, it was pretty fast and the steering system was somewhat slow for its driving speed.
All in all, it was a nice leisure build, created over the course of two evenings (one to build the crane, one to mod the locomotive and add the truck). It was fairly ugly but very, very playable and I had a good time unloading some cargo with it.
