Group 16 - Black & Decker Drill/Gate 1

Link to Main Page for Group 16

Gate 1

Work Proposal

Group 16 was assigned to a Black and Decker corded hand drill (Model No. DR202). The following is a breakdown of parts and the approach for the disassembly that the group will be following. All members of the group will be present during the disassembly but Kyle and Sanket will be in charge of disassembly. Notes, pictures, and videos will be taken during the entire procedure. It should take no longer than 60 minutes to disassemble the drill.

The drill is a mechanical tool that converts electrical energy into mechanical energy. It is made up of 6 main parts, made of various materials.

Main Parts
1. The Cord
2. Trigger Mechanism
3. Keyless Chuck
4. Gearbox
5. Electric Motor
6. The Housing it is enclosed in.

Tools required for disassembly:

1. 3/16 Flathead Screwdriver
2. Small Pick
3. Large Pick
4. Needle Nose Pliers
5. Small Wire Cutters
6. Torx Driver Set
7. Vice
8. Soldering Iron

Approach for Disassembly:

First we will start with taking the housing apart, a 3/16 flathead screw driver (or a #10-#21 torx driver) and pick will be used. There are 9 visible screws on the housing. After the screws are removed the housing can be carefully pried open using the pick and a screwdriver, while doing this we will remove the installed level and disconnect the cord. The cord may be male to female clips or soldered to the trigger switch in which we might have to cut it off with a small pair of wire cutters. Once we finish separating the cord, we will move on to disassembling the main components of the drill. We start off by removing the trigger and the forward/reverse switch using needle nose pliers and a flathead screwdriver. The gearbox, keyless clutch, and electric motor come out as one part and can be assessed further to be broken down into the components. It is assumed that the gearbox, keyless chuck, and electric motor are held together inside the drill by the housing and can be pulled apart, there might be a lock ring or some kind of press fit that could have been used during assembly. This means that we will have to pry the components apart using a screwdriver and possibly a vice.

Since one of the team members has worked on disassembling a drill earlier, it would probably take us around 3-4 hours to disassemble the hand drill. We have discussed the disassembly procedure and feel that we will not have any major hurdles through it. The only problem we face is to make the drill work, as it was given to us in a non-working condition. We first have to identify the fault in the drill and then try and repair it to make it work.

Capabilities of the Group:

There are no present weaknesses in our group’s skills to disassemble the drill. We do have weaknesses and shortcomings as individuals’, but it is balanced out by other members of the team. Everyone is eager and willing to work on the project as a group. Every member is assigned to be in-charge of different parts of the whole project.

Eric Kieffer:
Strengths: Effective communication skills, superior writing and descriptive skills, excellent public speaker
Weakness: Procrastination

Kyle Lynch:
Strengths: Excellent with AutoCAD, works well with tools, in-depth knowledge of machines
Weakness: Weak grammar skills

Alexis Wong:
Strengths: Excellent descriptive writing skills, pays high attention to detail
Weakness: Procrastination

Jonathan Lottes:
Strengths: Professional approach, works well with the team, enjoys working with computers
Weakness: Procrastination

Sanket Chavan:
Strength: Excellent with research, works well with tools, excellent note taking abilities
Weakness: Time management

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Management Proposal

Main Contact for Group 16: Eric Kieffer
Email:kieffer7@buffalo.edu

Introduction
The entire group knows that this project is going to be a big undertaking as each member is busy with numerous other classes and activities. Although this project is going to be a lot of work the group feels that if we follow our management proposal that all of the work will get done properly and in a timely manner.

Group Members and Responsibilities:

Eric Kieffer- Group Leader and Main Contact
Eric will be in charge of organizing each aspect of the project and distributing the workload of the project in a fair and even manner. The workload will be distributed by Eric with the strengths and interests of each group member in mind. Eric is in charge of outlining when each part of the project begins and will be due to submit to the entire group so it can be put up on the wiki in a timely manner. The meetings will also be set up by Eric by email and text message. Eric will also be helping out every group member in each aspect of the project when help is needed.

Kyle Lynch- Head of Solid Modeling
Kyle will be in charge of the solid modeling aspect of this project. Kyle is the solid modeling expert because he is interested in the topic and has some experience with it. Also, Kyle has access to a solid modeling program which benefits the group greatly. Before the solid modeling aspect of the project begins Kyle will be helping with the workload of the other group members when needed.

Jonathan Lottes and Alexis Wong- Wiki Developers
Jonathan and Alexis have taken on the creating of the wiki as a team because the group feels for in order for the project to look professional and impressive it would be more than a one man job. Both Jonathan and Alexis seemed interested in learning on how to create a wiki which will benefit the group as they both seem very eager to master this task. Together Jonathan and Alexis will be taking reports and various information given to them by the other group members and putting this information on the wiki. It is their responsibility to make sure the wiki looks organized and eye appealing throughout the project. Most of the information will be sent to them via email.

Sanket Chavan- Dissection and Reassembly Manager
During the dissection and reassembly it will be Sanket’s responsibility to take vigorous notes and to create diagrams when needed for the dissection and reassembly of the drill. Sanket will be responsible for most of the product dissection plan as he will know the most about this process. All aspects of parts and construction details will be the responsibility of the Dissection and Reassembly Mananger. Sanket will also be helping the other group members before his aspect of the project and during when asked to do so.

• All group members will have the responsibility of helping other group members when asked by the Group Leader.
  
  

Meeting Times and Location:

As of 10/6/2009 Group 16 will be meeting weekly on Tuesday nights at 4:30 pm at the Lockwood Library. Other meetings, times, and locations are sure to be needed and will be told to the group by the Main Contact for the group.

Plan to Complete all Necessary Work:

If each group member does their job as specified above then the project will get done in a timely manner that can be seen on the gantt chart below.

Gantt Chart
This chart outlines when each section of the project will be started and completed. The group will follow this model unless start dates or deadline changes are made by the group leader.



Conflict Resolution

Each group member is fully aware of their responsibilities for the project and are expected to take this project as seriously as they would a professional job. Although this standard has been set; the group does realize that conflict between group members or conflicts with deadlines and attending meetings may arise. To resolve these conflicts the group has come up with this solution.

-If a group member misses one or multiple meetings or deadlines (without a reasonable excuse) the outcome for this will be to mention the person’s lack of effort in the Compliance Matrix at the end of the project.

-If tension between group members results in a conflict the group members should contact the group leader about the issue and the group will have a meeting to resolve the tension. If a group member is still causing issues after being confronted by the group their actions will also be mentioned in the Compliance Matrix.

-The two situations above seem to be the most common conflicts that could arise and if they cannot be resolved with the outcomes described above then the group leader will contact the professor to help deal with the issue.

• Each excuse given will be discussed by the rest of the group and decided of its validity
  
  
  

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Initial Product Assessment

Intended Use
The intended use of the Black and Decker Power Drill is to accept various bits and rotate it with various torques.

Home Vs Professional Use: This product is geared towards home use because it is inexpensive. Professionals would look for a higher end model because reviews say the keyless chuck wears out after extended use and would not tightly hold bits. ₁

Different Functions: The different functions of the Black and Decker Power Drill include rotating bits in clockwise and counter-clockwise directions, and ensuring the drill is level with a spirit level in the back.

How It Works
The product operates by rotating the bit at speeds proportional to the pressure applied to the trigger. The direction of the rotation is determined by a three-way toggle above the trigger. The position of the toggle determines whether there is clockwise rotation, counter-clockwise rotation, or the drill is locked for safety, allowing no rotation. The spirit level works by partially filling a small tube with a liquid, leaving a small amount of less dense gas that will remain at the top of the tube. Small lines are printed on to show where the bubble should be when the drill is level.

Types of Energy: The drill uses electrical energy, mechanical energy, and gravitational energy.

Transformation and Modification of Energy: The drill accepts electrical energy through the power cord as an input, which is converted to mechanical energy by the motor to turn the bit and fan. It also uses gravitational energy so the bubble can be leveled in the spirit level.

Functionality
The product is not currently functioning and it is difficult to tell what is causing the problems currently. The electrical energy is not being properly converted into mechanical energy, suggesting that there might be a detached wire internally.

Complexity
Using a scale from 1 to 10, with 1 being a screwdriver and 10 being a milling machine, the Black and Decker Power Drill falls around a 4. This is because the drill has far fewer components than a milling machine, yet is still clearly more complex than a screwdriver, with the addition of a electricity, a motor, and a chuck for exchangeable bits.

Number of Components: It is estimated that there are around 10 components to the drill. This estimate comes from what is visible on the outside, such as the trigger for operator interaction, chuck to hold a bit, toggle to select safety or direction, bit to apply the work of the drill, cord to deliver electricity, spirit level to ensure the drill is level, and a casing to hold the components together, as well as what is believed to be inside, such as a motor to drive the bit, potentiometer to determine the speed of rotation based on trigger position, and a fan to keep the motor cool.

Complexity of Components: The individual components in the drill are not highly complex. The trigger, toggle, bit, casing, fan, and spirit level are very simple, with very few parts and easy to understand operations. The most complex parts in the drill would be the motor, chuck, and potentiometer. However these parts themselves are not very complex, as none have many parts.

Materials
There are number of different materials used in the drill.

Visible Materials: On the exterior, the case appears to be made of a plastic or polymer. The trigger and toggle are made of plastic. The bit appears to be made of steel. The spirit level looks as if it is made from a glass case partially filled with water. The cord is likely made of copper wiring encased in a rubber insulator. The chuck looks like it is made of steel and plastic.

Interior Materials: The fan is likely to be made of plastic or aluminum, while the motor is likely made of iron and steel. The potentiometer is estimated to be made of iron and graphite.

User Feedback
It is difficult to say whether one would be happy with this product, as the drill does not currently function, and the circumstances involved with the lack of functioning are unclear.

Comfort: The product is comfortable to use, with an ergonomically designed grip.

Ease of Use: The drill is easy to use, with only two simple mechanisms (trigger and toggle) for the user to operate.

Maintenece: The drill should not require regular maintenance. The difficulty in servicing the drill ranges depending on what the problem is, such as a loose wire, or a burned out motor.

Alternatives
There are many alternatives to the Black and Decker DR202 Power Drill, ranging in price and function. Some such alternatives include a simple screwdriver, a drill press, or competing power drills.

Screwdriver: A simple screwdriver would cost far less than the drill, but would require the torque to be provided by the user, which would likely be lower than that of the power drill. It also would not likely have exchangeable bits. However, as the screwdriver does not require electricity, it is more mobile and would not require any maintenance.

Drill Press: A drill press would cost significantly more than a power drill. It would offer more power than that of the power drill, and provide very straight plunges. However, the drill press cannot be manipulated as easily as a power drill, and is less mobile.
An example drill press can be found here. As can be seen, the price is much higher than that of the DR202, however the drill press accepts a larger bit size, more power, as well as a generally higher quality.

Competing Drills: Competing power drills would have varying advantages and disadvantages when compared to the Black and Decker Power Drill. These would likely include the quality of the parts used, which would be closely related to the price of the drills. Other drills may or may not have the keyless chuck and spirit level.
An example competing drill can be found here. As can be seen, the drill has traded a higher price for higher quality and more robustness.