Group 21 2012 Gate 2
This part of the project is concerned with the physical product and the dissection of it. During the dissection we are to follow the plan we previously made in Gate 1. We are also to evaluate our group after receiving feedback from Gate 1.
Project Management: Preliminary Project Review
Problems to Address
The previous plans we came up with as a group have not been working.
Major problems that need to be addressed are as follows:
- Wiki Organization
The main communication problems are as follows:
- \'\'\'Primary mode of communication was text messaging.\'\'\'
- Issues we had:
- One person was relaying messages to three other group members - This made it difficult to know who received what information.
- Texts were not responded to in a timely manner - Some group members claimed this was the easiest way to communicate with each other. We have found that to be untrue because of the lack of response from people. It was also very difficult to know when they received the messages, if they received them at all.
- Decision making as a group was difficult - We had to run options between people of the group numerous times. This was very time consuming as well as stressful. It was very hard to convey ideas with each other and finish a task in a timely manner.
- Solutions to the problem:
- Have group emails with everyone involved - This will ensure that everyone is receiving the same information in a timely manner. It will reduce miscommunication and variation in messages given to specific people.
- Enforce attendance at the weekly meetings - Easiest way to give someone information and know they are receiving it is by word of mouth. With everyone there as a witness, there will be no excuses as to why a specific person did not fulfill their given task on time. If group members do not attend the meetings, it will be noted in the final group evaluation.
- Issues we had:
- \'\'\'Miscommunication of assignment due dates.\'\'\'
- Issues we had:
- Team members were not volunteering to help with the work until the last minute - This was very frustrating seeing that each group member has the same resources and tools to find out when assignments are due. Group members were either lazy or busy with other classes to realize so much time has passed between each gate.
- Team members were not completing their assigned tasks in a timely manner - When asked to participate in part of the assignment, the group member was given a due date to finish his or her part. These deadlines continued to not be met because of either the laziness or busy schedules of the group members.
- Solutions to the problem:
- Team members not carrying their weight were talked to and have been put on notice - We have talked to the specific group members who continue to bring us down and get us poor marks. They have been spoken to and hopefully they now see the importance of this project and the importance of working together and being a team player. If these problems continue, we will have to find some other alternative actions.
- A schedule with itinerary has been posted with due dates and individual tasks needed to be done each week - Each group member knows about the new schedule. In this schedule, it will show what needs to be worked on each week and when assignments are due. If a group member misses a weekly meeting or is uncertain about a due date, they can look here. There is no longer any excuse for a group member to not know when an assignment is due. There is a link in the "contents" section of this page so it can be easily found. The table below shows our progress up to this gate. There is also a link on our main page to the Project Management section for all group members to reference to.
- Issues we had:
\'\'\' Table 1: Weekly Schedule \'\'\'
|Week of Sept 10||Week of Sept 17||Week of Sept 24||Week of Oct 1||Week of Oct 8||Week of Oct 15||Week of Oct 22||Week of Oct 29||Week of Nov 5||Week of Nov 12||Week of Nov 19||Week of Nov 26||Week of Dec 3||Week of Dec 10|
|Section 1: The Four Factors|
|Section 2: Product Complexity|
|Section 3: Product Cost and Ownership|
|Turn in Product Proposal||Due 9/12|
|Turn in Gate 1||Due 10/8|
|Preliminary Project Review|
|Turn in Gate 2||Due 10/26|
|Cause for Corrective Action|
|Solid Modeled Assembly|
|Turn in Gate 3||Due 11/16|
|Cause for Corrective Action|
|Turn in Gate 4||Due 11/30|
|Finalization of Deliverables|
|Oral Presentation||Date TBD|
|Turn in Gate 5||Due 12/ 14|
|Gate 1 Tasks|
|Gate 2 Tasks|
|Gate 3 Tasks|
|Gate 4 Tasks|
|Gate 5 Tasks|
\'\'Wiki Organization \'\'
In our first gate, we were marked down highly because of our disorganization of the wiki page. This problem has been solved by reading the comments and feedback we received and making some corrections and revisions to our first gate. We also have put more preparation and effort into Gate 2, given better time management. We believe this will help us with the marks we receive in the future.
A recurring problem we have been having as a group is the poor attendance not only to the weekly meetings, but to class as well. Class is an easy way to meet with group members. It is a time in your schedule you know you will be in the same area and do not have to make any extra accommodations. To solve this problem, the team members who have been attending have made it known to the others that this will not be tolerated anymore. It is hurting not only our project grade, but our individual over all grade for the class as well. They have agreed to put in the same amount of work that each of the other group members have.
What has been working
To this point, the major thing that has been working for our group is having one person in charge of everyone else. This person has been making the major project decisions and assigning group tasks. Any task that has gone unfulfilled or unfinished, this person has taken on the heavier work load for the group. This ensures that tasks are getting done, despite the lack of effort from the other group members.
Product Archaeology: Product Dissection
Our task for this part was to dissect our product, the men\'s Spalding B.L.A.D.E. 10 Speed Bicycle.
Beginning condition of the bike
- Rear tire flat
- Rear tire falling off frame
- Front tire flat
Below in Table 2, we describe what steps were taken to dissect our product. Overall difficulty is a factor depending on time and physical effort needed to remove the part.
Tools you will need before you begin:
- Set of allen wrenches
- Wrench (10 mm, 13 mm, 15 mm)
- Phillips head screwdriver
- Bearing press
\'\'Table 2: Dissection Guide of Spalding B.L.A.D.E. 10 Speed Bicycle\'\'
|Step #||Part Name||Component of which subsystem?||Tool Used||Comments||Time (minutes)||Physical Effort (1-5)||Overall Difficulty (1-5)||Picture|
|1||Front Wheel||Steering/Body||13 mm wrench||Few turns and the two nuts came off the axle. Tire came off easily.||1||1||1|
|2||Front Brakes||Brakes||10 mm wrench||Few turn to take off two bolts. Wiring was difficult to maneuver.||5||2||3|
|3||Shifters||Shifting/Power||Phillips head screwdriver||Took more time because of rust.||3||2||2|
|4||Hand Brakes||Brakes||Allen wrench||N/A||3||1||2||See above|
|5||Handlebars||Steering||Allen wrench||Very easy.||2||1||1|
|6||Handlebar Brace||Steering/Body||Allen wrench||N/A||1||1||1|
|7||Seat||Steering/Body||13 mm wrench||Took a long time because seat axle was very rusty.||10||4||4|
|8||Rear Brake Pads||Brakes||10 mm wrench||N/A||5||2||3|
|9||Reflecter||Body||10 mm wrench||Popped right off.||2||1||1|
|10||Rear Gear System||Shifting/Power||
||Couldn\'t remove until we removed the rear gear system. Tire was taken off easily after.||3||1||1|
||Very difficult and very rusty. Tried many different methods before this one worked.||45||5||5|
|13||Chain Protector/Mover||Shifting/Power||10 mm wrench||Gravity took it off during our dissection, but in normal cases, use the tool specified.||1||1||1|
|14||Kickstand||N/A||10 mm wrench||Rusty and needed some man power to finally remove from frame after bolts were removed.||10||4||3|
|1||Very Easy||Took little time and little physical effort|
|2||Easy||Took little time and some physical effort|
|3||Neutral||Took some time and some physical effort|
|4||Difficult||Took more than 5 minutes and takes moderate physical effort|
|5||Very Difficult||Took more than 10 minutes and could only be removed by special mechanisms|
The entire dissection process went pretty smoothly, as we encountered only one main problem and a minor annoyance along the way.
The bike is pretty old and has been enjoyed and used by a customer for many years. Because of this, we ran into problems getting parts to disconnect from the frame because of how rusty they were.
- The bike seat- This was given a difficulty rating of 4 for this reason. It should normally slip out with human forces to allow the seat to be easily adjusted.
- The kickstand- This was given a difficulty of 3 for this reason. It has obviously been exposed to the elements for a long time. It was very rusty and should have come right off the frame after the bolt was removed.
Our toughest challenge during the dissection was attempting to remove the pedals. We could not get the pedals to come off. We tried a variety of things in the lab,(banging on it with a hammer, creating a lever with a screwdriver and hitting that with a hammer, brute strength, etc.), but we could not get it off with any of the tools that were available. After exhausting ourselves in the lab for over 30 minutes, we consulted a professor and he referred us to the machine shop in Jarvis Hall. A man there helped us, and set up the bearing press to generate the proper amount of force needed to separate the pedal from the rest of the bicycle. There was a shaft that connected the pedal levers that we could not see, that was being covered by a casing, that was keeping us from easily separating the two parts. After this part was removed, the chain guard literally fell to the floor. No tool was needed to remove it. For the time put into this one part, physical effort put forth, and the fact that it was finished outside of the dissection lab with expert help needed, we gave this an overall difficulty of 5.
\'\'\'Parts we could not remove\'\'\'
- Cable to rear brakes - These could not be removed unless we were to cut them. If we did this, we would not be able to complete the reassembly part of the project.
- Shifting cables - They were never meant to be removed. We can see this by evidence of the method used to strap the cable to the frame. Again, to remove this piece, it would need to be cut, thus making it nonfunctional.
- Chain - This could not be removed unless cut. We can tell the manufacturer did not want this removed by the way they did not provide a master link. They probably did this so of the chain fell off the gears for some reason the user would not lose it. If we were to cut the chain, to keep the bike functional after reassembly, we would have to add a master link to it. We decided against it.
- Rubber pads on handles - We decided to leave these on because they have no real mechanical function to add to the bike. They are there for the comfort of the user.
- Frame pieces - There are many different pipes that connected the frame together. We could tell these were not meant to be taken apart because of the manufacturer\'s decision to weld them together.
The connection of the main subsystems in a bicycle is very interesting to study, as they all affect each other in one way or another.
The four subsystems that will be analyzed are:
- Power system
- Steering system
- Braking system
- Body system
Each of these has a major effect on the others, and all the systems must be functioning well for the bicycle to work effectively.
The power system notably includes the pedals, wheels, chain, gears. The power system, which is used to accelerate and to “drive” the bicycle, is physically connected to the steering system through the front of the frame, where if the wheels are turned, the direction of the motion of the bicycle is changed directly with the change in angle of the handlebars, relative to their original position. When the pedals are turned, the gears are rotated relative to the force that is input by the rider. The gears are connected by the chain, which causes the wheels to rotate.
The steering system notably includes the handlebars and grips along with the wheels. The steering system is very intuitive for the rider, as a simple hand motion in one direction causes a direct change in angle of the wheels relative to the frame. This causes the bicycle to change its relative direction, which can be done while the bicycle is moving forward.
The braking system includes the brakes located near the handlebars, the wheels, and brake pads. The braking system is physically connected to the drive system by the use of cables and brake pads. When the brakes are squeezed, a signal is sent through the cables which squeezes the brake pads on the tire, which slows down or stops the bicycle from moving. The braking subsystem uses a signal that is submitted through cables. The rider squeezes the handlebars with the desired power, where more power results in the bicycle slowing down or stopping at a faster rate than if the rider were to do it lightly. The signal is sent through the cables, and this causes the brake pads located around the wheel to move inward, using friction to stop the rotation of the wheels, or just decrease the speed. When the speed of the wheels decrease, the speed of the body and everything else on the bicycle slows down directly with it.
The frame subsystem simply includes the frame, wheels, and spokes which are all used to support the rider. Materials for the frame were discussed in gate one, which carry a variety of different properties. The shape of the frame is optimum to support the largest weight of a rider possible, as allowed by the material properties.
How they work together
The power subsystem is also physically connected to the frame subsystem because the wheels are connected to the aluminum frame. The steering and braking subsystem also work in conjunction as when the braking subsystem is used, the bicycle will slow down smoothly as long as the handlebars aren\'t turned too much. The body subsystem is connected to the steering and braking systems each because the steering and braking systems result in the body moving, which will subject the wheels to different surfaces that will affect the motion of the bicycle. The subsystems of a bicycle are connected to ensure full functionality, as the subsystems all have very different but imperative functions. The braking system is connected to the steering system because sometimes it is necessary for the rider to slow down while he is also turning, not just riding in a straight line. The braking subsystem acts as somewhat of a negative to the power subsystem, as the brakes are used to slow down the bicycle, as the power system speeds it up. The body must be connected to all other subsystems because that is what supports the rider.
This specific mountain bike, compared to other bicycles, is designed to withstand more harsh weather conditions. The tires are designed to have better traction when riding in off-road environments, as opposed to some distance bicycles which are designed to operate efficiently on roads. The frame is also thicker and more compact than other common bicycles, as it must be made to withstand rougher terrains and greater vertical forces.
The societal factors apparent in the connection of the subsystems are especially evident in the braking subsystem. The fact that the brakes can be used in conjunction with the steering subsystem is an important safety feature, as it would be impractical to have to straighten out the wheels every time one wanted to brake. The reason the handlebars are placed where they are is because of the convenience for the rider to be able to do a simple and intuitive hand position adjustment to turn the wheels of the bicycle. There really couldn\'t be a better place to place the handlebars, as the hands must be used to steer the bike, and they are used in a place that also supports the rider. Since the bicycle is such a simple yet effective design, the brake pads must be placed where they are to stop the wheels, as there is no more efficient way to stop the bicycle from moving. The power subsystem is located at the position it is on the body because the riders feet are used to “drive” the bicycle. Therefore, this subsystem must be located near the rider\'s feet, and they must be connected to a wheel by a chain and gears to physically rotate the wheels, causing a vertical translation in the motion of the bicycle.
Designers often like a strong, but lightweight frame. Frames are also aimed to be lightweight as a safety feature, because often small children are riding bicycles, and the lighter the bicycle is, the less chance of a serious injury occurring. This is a global factor because in our region, children ride bikes for fun and will act reckless with them and use them for entertainment rather than day to day transportation. They are known for making unnatural obstacles and using the bike to go over them. This mountain bike was not designed for the large number of people in a large city that would be using it for daily transportation. Its design features are aimed at riders who will be using it in off-road conditions.
For all subsystems of the bicycles, the goal is to use cheap but effective materials, as economics must be taken into consideration. This is what makes aluminum a popular choice for designing most bicycles.