User:Gknapp2779/Project1

Project Preference

 * 1) Power Wheel
 * 2) Maker Bot PLA Characteristics
 * 3) Wind Turbine

Problem Statement
''In one or two sentences, describe the project that your group will be working on. Identify which one or two CDIO documents your group will create in this project cycle.''

Over the next several weeks, my group will continue the work on the Autonomous Power Wheel where the last group left off. This involves creating code and mechanism that will make a children's Power Wheel automated.

Project Plan
Briefly describe your group's plan for the next 4 weeks, including the specific activities that will take place each week.

Over the next 4 weeks, my group plans on finishing the work that the last group did on the Power Wheel's steering and to figure out a way to automate the braking system as well. To finish of the steering we need fix a jamming problem that occurs upon use. As for the braking problem, we must design a code and some sort of mechanism that applies pressure on the gas pedal to accelerate the car, and then takes pressure off the pedal to stop the car.

Week 1 Narrative
During Week 1, my group needed to figure out what the last Power Wheel group had done, so we did some research on their Wikiversity page. The page said that the Power Wheel could turn by it self using a specific code. The code basically made the car veer left and then straighten on. Unfortunately, when we tried to make the Power Wheel work, the Power Wheel would not turn. We tried replacing the batteries because they were dead, but the Power Wheel still did not work. Eventually we realized that the Power Wheel was not turning because the turning mechanism was jammed on itself. So, we took apart the turning mechanism, re-positioned it, and then returned it to the way it was supposed to be. The mechanism needs an adjustment to stop it from turning to far and getting stuck on the end of itself.

Week 2 Narrative
During Week 2, my group went through a few designs for what the braking mechanism should be. We were set on making a Linear Actuator push the pedal. I made a design for a small platform to place the Actuator on. The platform would hold the Actuator so it was perpendicular to the pedal and pushing near the top of the pedal to create less work for the Actuator to do and more torque to push the pedal respectively. I even found the actuator that I thought we wanted: http://www.mcmaster.com/#70155k78/=oq4amv

The equation for Work: F*d*cos(Ɵ) F=Force Exerted

d=Distance traveled

Ɵ= The angle of Force in relation to the object

The equation for torque: T = r*F*sin(Ɵ)

r = Distance from the fulcrum to the point of exerted force

F = Force Exerted

Ɵ = Angle between force vector and lever arm vector

Unfortunately, Professor Edelen made a good point that if we were to use these actuators, we would have to continually give the actuator power for it to work, and that would waste a lot of power. So, we decided to go with a stepper motor design instead. I made a design where the motor would pull a string(or some other attachment) that would be a attached to a lever, and the lever would in turn push on the lever to move the Power Wheel. To stop the Power Wheel, we would program the motor to reverse the motor to take of the pressure off the gas pedal.

As for our problem with the steering mechanism, it still was not working even after we fixed the jammed gear. We took it apart to see if there was anything wrong with it, but we saw no problems. We plugged the steering mechanism into the power supply to see if it would work, but the motor did not turn until I turned the Power Supply up to 12 Volts and about 30 Amps. The motor was not working because the batteries we were using only gave 12 Volts and 5 Amps. So we realized that the only way this Power Wheel was going to turn away from the Power Supply was if we got a much stronger battery with more current.

Week 3 Narrative
This week, it was my job to make a possible prototype for the mechanism that pushes the go pedal on the Power Wheel. I measured some important dimensions of the Power Wheel that I would require if I were to build the go pedal mechanism at home. With the help of my team and Professor Edelen, I calculated the distance that the lever would require to output enough force to push the pedal.

Height from Power Wheel floor to the top of the Pedal: 10 centimeters

Length of the Lever: 21 centimeters

Distance from the Pulling Force to the lever's axle: 14 centimeters

At home I started putting these measurements to use. If the top of the pedal is 10 cm, than I want to have the lever push about 3 cm below the top. If the length of the lever is 21 cm and the axle is 14 cm from the top, then that leaves 7 cm below the axle. Then I'll require 2 or 3 cm above the axle for support. So the height of the lever supports are about 17 cm (=(10-3)+(21-14)+3). I made 2 supports 17 cm high and I drilled a hole about 3 cm from the top of each. I drilled a hole in 14 cm down the lever part and inserted a dowel rod through the supports and lever and hot glued the supports to the dowel rod; I left the lever free to spin.

Near the bottom of the lever, I drilled a hole an tied a line with a fishing weight through it. This will cause the lever to return to its starting point, off of the pedal, when we want the Power Wheel to stop. At the top of the lever, I drilled a hole and tied a string through it for the motor to pull the lever.

Week 4 Narrative
For the fourth week, we made another design where our motor would spin a bolt nut with an extension into the pedal. The motor will be on an elevated platform so it screws into the top of the pedal for the most torque. Since we had so many designs, we made a decision matrix to help us decide which design to use.

(This matrix is also on the main project design page.)

As you can see the Screw Design has our the highest amount of points among the designs, so we are going to deem this design as our final design. If we end up getting this project again, we will make a mount for the motor and an extension for the bolt. After that we would do tests to make sure it worked and try to implement a code into the Monster Motor shield.