Question 1: What was the general strategy or plan behind your bot design?

Go fast, turn faster.

Question 2: What technologies/mechanisms did you use?

Turntable front wheels. BrickOS code. BrickOS allows me to do some things easier & faster that I could with the standard code.

Question 3: What was the most challenging aspect of construction?

Actually, I built Ben Hur for another contest, and it's had several successful runs in competition.

Ben Hur actually evolved through a couple different stages. At first, I just built a three wheel robot with a small caster on the back, the RCX, two drive motors, and a long boom for the light sensor(s) in front. As my design evolved, I made the 'back' wheel bigger & bigger. Finally, I moved the RCX behind the pivot, with the back wheel. This version, called "Lego Lightning" won a line following contest against non-LEGO robots. Lego Lightning only had a six inch turning radius, so it wouldn't run on a course with sharp turns.

That is when I built Ben Hur. It was designed using only parts from the standard RIS set, so it could enter a specific event. I've made some changes to the front to re-enforce the axle the front wheels pivot on, but it still only uses parts from a single set.

Question 4: Are there any special features you care to talk about?

Ben Hur includes all the line following 'tricks' I know into one robot. The front wheels, motors and light sensor(s) will easily pivot, allowing it to turn and adjust to the line very quickly. The wheels are close together, so it will turn faster, and the sensor is extended a long way from where the wheels pivot, so it doesn't have to turn as far to move the sensor on or off the line.

The RCX (most of the weight) is mounted on a trailer behind the drive wheels, so it does not have to rotate while the robot is searching and adjusting to the line.

Question 5: What surprised you about how your bot behaved/performed during the event?

I really didn't expect it to be that consistent in the accurate stop event. It took about six inches to stop, but it hit the exact same mark every time.

Also, I had written a program for the "Continuous Line" event that was designed to follow the edge of the line, and when I ran it the day of the event, it was completely un-reliable, because at full speed, Ben Hur would easily cross the line too quickly. I resorted to using a 'standard' line following program, which, during the competition runs, also proved to be unreliable, but still much better than my original program.

Overall, Ben Hur performed as I expected in the first part of the line following event, and better than I expected in the second and third parts.