Oil Rig: Drilling for Lego Technic

Cyrus Tabrizi, 7/11/12

      This was my entry to the Eurobricks TSATS competition. It was an oil platform that combined a number of remotely-controlled functions with a unique shape and crew. It is one of my few models that do not have wheels and I think it was the only one to have been oriented around water. In this regard, it certainly stood alone (no pun intended) but its design and construction are unique as well.


      The main body of the oil rig is built in the shape of an octagon -not something you see very often in legos nor in real life- and making the structure stable while fitting in the number of motors and functions that I did was not easy. Considering the number of 45 degree angles that were present, I'm surprised it turned out as nicely as it did. This octagonal design and the extending legs give it a unique profile, one that is ultimately fictional and completely different from real platforms. Mechanically speaking, it rests on four pneumatically raised legs, each with air suspension  and roughly 90 degrees of motorized rotation. The four pumps are controlled via a switch that can be accessed from the side of the platform and the air supply comes from two hand pumps below the battery box. The rotation of the legs is controlled by two XL motors (one per pair of legs) such that they work in unison to turn each of the legs. The legs can be positioned so that they are perpendicular to each other or parallel to either of their respective neighbors. This stabilizes the entire platform in the direction that the legs are aligned to-as such, the perpendicular position is the most stable in general, but other positions can be used when an outside force (such as wind or waves) is set against a particular side of the platform. The rig has a drill arm that can be raised and lowered via one M motor. At the bottom of the arm there is an original Lego drill that spins via gearing and an M motor that is mounted near it. This was the only viable setup as the movement of the drill arm presents a problem in terms of transmitting power to the drill head. The possibility of having an axle (such as 32-long one from the 8421 Mobile Crane) that moves with the arm and then spinning it through a sliding gear was considered but was disregarded after a bit of testing.

      All in all, I think the model does a good job of combining an interesting set of functions with a unique appearance, but the main problem with the model lies in the fragile nature of the platform's legs. When on slippery surfaces like glass, the small contact surface of the leg's base is insufficient to keep the legs from sliding and the bending of the actual legs themselves when under too much pressure only adds to the instability of the heavy structure. Although the function of rotating the legs relies on the legs being able to slip, the legs are not sturdy enough to prevent the entire structure from twisting. One solution to this would be to attach some rubber Lego treads to the base of the legs -this would add traction and prevent slipping -and to move the center of the leg's contact surface to below the center of the turntable -this would mean that the legs could spin even with the additional friction caused by the use of Lego treads on the feet.

More pictures can be found on Flickr.