Small RC Scraper

Cyrus Tabrizi, 1/14/12

      For the August 2011 "Record Breaker" Technic Challenge, I decided to build the smallest, fully-functioning, and remotely controlled Lego scraper. It was built the night before the deadline and works relatively well for a quick build. Many of you might be wondering why I didn't build a cabin. I did this to save time, and because it looks more streamlined. Pretend that it's an "automated" scraper, one that does not need the presence of an operater to function.

      Regarding its operation, it is controlled by two remotes. One remote controls the drivetrain and steering while the second controls the two bucket functions. For a drivetrain, there are two seperate XL motors, one in the rear, and one in the front. Each one powers its own axle through a differential. There is one detail missing though. In a real scraper, there are two seperate engines, one in each section of the vehicle. However, I only managed to place a single V6 engine in the front compartment. To connect the front and rear sections together, there is an arm that extends from the rear, and attachs to a turntable located in the front. To steer this arm, and, consequently, the rest of the vehicle, a linear actuator is used. It is powered by one M motor with a worm gear and a clutch (1:9). This makes steering slow but controllable as well. Because of the placement of the linear actuator, and the distance between the front and rear axles in regards to the turntable, the steering radius is not that large. This is a problem that will be explored in future models.

More pictures can be found on Flickr.

Scraper 1
Scraper 2
Scraper 3
Scraper 4

      The main function of the scraper is its bucket. One M motor lowers and raises the bucket into or above the ground. The second M motor controls the positioning of the lid, preventing or allowing the bucket to pick up or unload its cargo. Both of these functions are built with worm gears, as that is the most efficient method of keeping the position of the bucket and lid locked.

Scraper 5