My daughter and I are having a great time with the GoPiGo! But we're having an issue with Mission 2. We built a simple obstacle course (shown in the attached picture), but we are finding that our turns are too unpredictable to make our GoPiGo complete the course consistently. For example, on average, turning left for 1 second gives us a 90 degree turn, but it seems to vary randomly by up to 30 degrees from that. Since our obstacle course requires 4 turns, by the end, we can be randomly off by quite a bit. About a third of the time, the robot makes it through the finish gate; about a third of the time it is off to the left; and about a third of the time it is off to the right. Any suggestions? We'd like to make a more complicated course, but it doesn't seem like it will be possible unless we can control the turns more consistently.