Embedded Files
Overview
Overview
FERRIS WHEEL
Our second concept is titled The Ferris Wheel, which involves a wheel rotating, a light sensor, a basket, and two opposing tracks. The sculpture begins with the chaos kit marble rolling from a track into a basket attached to the said Ferris Wheel. It will then trigger the light sensor sending a message to the Lego NXT to, "Start the motor!". This will then began the rotation of the wheel causing that marble to release from the basket at about between 90 and 45 degrees from the origin. Once the marble is released, it will fall onto the opposing track and go to the next sculpture.
Fig. 2: Our concept design for our Ferris Wheel idea.
(Should say light sensor instead of touch sensor)
IMG_4240.movWorking Model 2D Simulation
This simulation shows the error and risks along with the Ferris Wheel. The major risk was the ball falling out of the basket due to the speed of the Ferris Wheel.
IMG_4242 3.21.46 PM.movWorking Model 2D Simulation (Fixed)
This fixed simulation shows the approximate velocity needed in order to keep the ball falling on the track. It is a reasonable speed and it has all of the previous steps attached.
Design Challenges
Design Challenges
The wheel design calls for tedious steps that allow for minimal to no error. The first error that occurred was managing the speed of the wheel, as shown as the video simulations above, the ball may fall out before the opposing ramp due to a small velocity. We had to test the design with multiple speeds to limit it down to one velocity that would not be too fast that it rocketed the marble and would not be too slow that there was no force pushing the marble from the cart to the track.
Another error was with the correct height of the ramp and the marble. One error analyzed in WM2D, but not shown on a video, was the problem of the placement of the track. If the track was too high, the ball would miss, and the same for a track too low. In conclusion, to fix this we tried multiple heights and angles so that the ball would have accuracy and fall directly into the basket without falling out or jumping out. One side of the basket was also exposed, making the marble fall out when going in, so we added a taped border to make the transition work smoothly.
The programming of this design was also a bit finicky. Since the motor was intended to turn 180 degrees when the
Programming
Programming
The goal of the programming was to begin the rotation of the wheel using the motor when light sensor one is activated, and then that triggers the wheel to rotate and release the ball. We then programmed the motor to stop the code after reaching a desired location, that was at -90 degrees, or 270 degrees. Its original starting position was 180 and its release was around 90 to 45 degrees. We programmed the code to stop here to not allow for any error where the ball was released after the desired degree period.
Light Sensor - With the light sensor we used if then code sequences that looped if not answered. Such as keeping the code stopped if the ball is not touching sensor and starting the code if the ball is touching the sensor, then moving the motor and etc.
Specific Location (Motor Stop!) - We also used a if then code structure for this part of the code, sensing if the motor had reached a certain location it would identify if it was at the location or not and then we would use the else stem to say, if it is not there, then keep moving the motor. We did not need the position to be super accurate, but we still needed the code to stop at a specific location so the if then else structure was crucial.
Results
Results
IMG_4242 3.21.46 PM.movWM2D Simulation of Ferris Wheel Concept
p2.mp4Physically Implemented Ferris Wheel
Top view of Ferris Wheel
Ferris Wheel with Track
Side view of Ferris Wheel
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