Here he is in all his World Championship glory.
The most obvious modification is that scary-looking blade. The blade was deepened to allow easier loading of irregularly arranged sacks. Vertical plates were added; guiding sacks to the center of the blade when lifting to reduce the number of bags tossed outside of the dump bed. Notches were laser-cut an inch off the leading edge to prevent bags from sliding off the front of the blade when backing away from a barrier.
Here you can see Remus with blade and bed lifted. Four 393 motors work simultaneously to lift the bed. Two 393 motors are used to lift the blade. All lifting motors are fitted with six-tooth, high-strength sprockets. High-strength chain then drives thirty-tooth sprockets resulting in a torquey 5:1 ratio. Remus was routinely tested to lift up to 5 sacks at a time with his blade and over 20 sacks in his bed.
Remus utilizes ten 393 motors to move his hefty (20lbs+) frame about. Four motors lift the dump bed, two motors lift the front blade, and four 393 motors power his 6-wheel-drive. The drive-train is actually made up of two, fully independent units; one on each side. On the left side, two 393 motors drive idler gears that drive three other gears (in a 1:1 ratio) attached to the drive wheels. This is mirrored on the right side. Being fully independent, these drive-trains allow Remus to spin freely and quickly on his own footprint.
To prevent sacks from being pulled into the meshing gears, guards were installed with some improvement; they can be seen in the center photo.
Only four omni-wheels were used on each robot. There are several reasons for this. First, we only had eight wheels and two robots. Second, only four are really necessary to have an easy-spinning robot. Finally, we believed that the one set of solid wheels in the center might prevent the robot from being easily pushed around (particularly side-to-side). We soon discovered that omni-wheels are a tiny fraction of an inch taller than the solid wheels, so rubber bands needed to be wrapped around the solid wheels to make them actually stick to the ground. You can also see in this photo the aforementioned 1:1 drive ratio. Taller ratios were experimented with, but ultimately, this ratio was thought "quick enough" and was much easier on the drive motors when rapidly changing direction.
Starting position. Measurements - 17.5" x 17.5" x 17.5"
Above. Steel plating was added above the bed to prevent sacks from falling in-between the bed and the upright frame.
2013 Robot Tech Info