Drill Disection

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GATE 2: Product Dissection

Purpose

The purpose of this gate is to put our gate 1 planning into actual practice. We will be dissecting the Black and Decker drill in order analyze each subsystem, understand better how and why this power drill is put together the way it is, and understand how any global, societal, economical, or environmental factors have contributed to its design.

Project Management: Preliminary Project Review

Project Management

The following information is a project management report for Group #20 and will address the following topics:

1. Effectiveness of the original plan presented in Gate 1
2. Unresolved Conflicts/Challenges
3. Conflicts/Challenges that have been addressed and the course of action taken to correct the issues

Our original plan outlined in Gate 1 consisted of the following: The group would meet every Saturday around 9:00 am on the second floor of Capen Hall and would continue to make any necessary progress towards the completion of the next project gate, as well as discuss assigned tasks, and discuss issues arising with the project. Thus far, everyone has made it at the specified time, and has completed their portion of the work.

1.Why the plan has worked thus far:
The reason the plan has worked well to this point is due to the fact that regardless of how much work is to be done the group has consistently followed the plan of meeting each week. This has allowed us to stay in contact for large and small issues. The only foreseeable problem is the fact that this is the only method we have employed to effectively communicate with one another. Texting and e-mails seem to be ineffective and time consuming. So, if an emergency regarding the project should arise mid week their is the potential for communication lag and problems regarding the resolving of the issue at hand.

2.Unresolved Conflicts/Challenges:
Unfortunately, as a group we did not score well on project Gate 1. This is most likely due to the fact that what was asked for by the professors seemed unclear. We also had less time to work on it than was optimal for the situation. The errors have been pointed out by the graders and we, as a group, will attempt to rectify these issues and keep them in mind as we proceed with Gate 2.

3.Conflicts/Challenges that have been addressed:
One of the first challenges the group had was addressing how to divide the work. With Gate 1 everyone met and answered the questions quickly, but ineffectively (as can be seen from the received grade). Then, our wiki expert Nate Mountain added and formatted all the information into the wiki page. The problem with this approach is that we only briefly skimmed the surface in answering the questions, and our grade reflects that. Our solution to this problem is that for Gate 2 everyone has a specific set of questions from the gate to answer. For example, one person tackled the project management report. Two others worked together to complete the section of questions that address the difficulty of dis-assembly of the product. The last two members addressed the connection of subsystems. This allowed for each member to discuss with one another their assigned questions, and spend the necessary time to think through each question and give a reasoned answer. Our hopes are that by taking these steps we will have more effective answers for each question of Gate 2.

The only other issue we have experienced so far was during the dissection of our product. We had almost completed the product dissection when we realized that we needed a star nut to take apart the chuck assembly of our drill. Since none of us currently possessed one, and the lab was closed, we waited until the following week which allowed us to obtain the necessary tool to continue the final portion of the dissection. This effectively solved our issue. This speaks to the effectiveness of our established plan. We did not have the necessary tool, but we had left ourselves plenty of time to obtain the tool and finish the dissection without getting ourselves into a time crunch.

Product Archaeology: Product Dissection

Dissection Process

Difficulty Scale

Each step of dis-assembly was of a different difficulty than the step preceding or following it. For this we developed a 4 star scale of difficulty for the dis-assembly process of the drill. Its breakdown is as follows:
*-Very Straightforward: This level of difficulty is assigned to the extremely simple aspects of dis-assembly that require very little thought or planning. Ex. pulling something apart after all the screws have been removed
**-Relatively Simple: This level of difficulty is assigned to things that are somewhat more complicated than the “Very Straightforward” aspect of dis-assembly, this stuff that require some effort on the dissectors part. Ex. the use of a screwdriver to remove screws holding two pieces of the drill that are being held together
***-Complicated: This level of difficulty is assigned to the aspects of dis-assembly that require some forethought and a plan of attack and a careful hand by the dissector, it is substantially more complicated than the “Relatively Simple” and is the biggest jump in difficulty on our scale. Ex. having to remove gears from the inner casing and remember their orientation and the way they fit back into the drill
****-Extremely Complicated: This is the highest level of difficulty that can be assigned. This denotes steps in the dissection process that kept us stumped for a long time and required further research to figure out the steps required. When the required steps were figured out a lot of effort was still required to follow those steps. Ex. reassembly of the drill to remove the truck of the drill and continue dis-assembly

This scale proved to be a very accurate representation of the difficulty involved with dis-assembly of this product.

This product is not exactly intended for dis-assembly as there is no reason for dis-assembly because the usual reason for dis-assembly is customization. There are no modifications for this product that would require dis-assembly. This being said it is still fairly easily disassembled through the removal of a large number of just normal Phillips head screws. There was one star screw in the head of the drill. A star bit suggests that it is not meant to be unscrewed by the average user of the drill. In sum, the drill has no reason to be disassembled as there are no options for customization which would be the primary reason for dis-assembly. However, the majority drill can still be disassembled with relative ease by the normal consumer of this product with just a Phillips head screw driver.

Dissection Table
STEPS	OBJECTIVES	PICTURES	TOOLS REQUIRED	CONSIDERATIONS/NOTES	DIFFICULTY
Step 1	Remove the chuck from drill.		Hex key set	Find the right size hex key that fits down into the bolt on the inside of the chuck of the drill and activate the drill counterclockwise. The chuck should come off once the bolt is unscrewed.
Step 2	Separate battery from drill.		Hands	NONE
Step 3	Remove all 9 screws from the outer casing of the drill: 2 long screws, 5 medium sized screws and 2 short screws.		Philips Screwdriver	We recommend organizing the screws in a way that you can remember where each one went, since there are three sizes.
Step 4	Starting from top of the drill carefully pull apart the 2 halves of the outer plastic casing.		Hands, Flathead screwdriver	Be careful not to break the plastic. Consider using a flat head screwdriver to separate pieces.
Step 5	Remove the electrical components of the drill.		Hands	NONE
Step 6	Remove the motor in its plastic casing from the external casing of the drill.		Hands	Have a rag handy because grease will get on your hands at this point.
Step 7	Remove the four screws holding the motor onto the head of the drill.		Philips screwdriver	NONE
Step 8	Remove the primary level of gears.		Hands	Do not wipe grease off of gears, it is there for a reason.
Step 9	Remove 2 screws that were holding the casing for the primary gears to the rest of the drill.		Philips Screwdriver	Make sure these screws as well as all the ones before are separated and organized.
Step 10	Remove secondary level of gears.		Hands	Once again, attempt to keep all grease on gears.
Step 11	Remove the torque adjusting mechanism from the gear housing.		Hands	NONE
Step 12	Remove the 4 screws on the gear housing.		Philips Screwdriver	Keep screws separate and organized.

Looking at the drill as a whole it was a fairly simple process of dis-assembly. We did hit snags at particular points of the dis-assembly process. For example, at one point we had to reassemble the drill completely to be able to remove the chuck which was necessary for the final dis-assembly steps. This showed us that it is always not a straightforward process to disassemble something, sometimes it is necessary to go backwards to be able to move forward with the dissection process.

Each step leading up to step 10 was very straightforward and required very little thinking. At the point when we reached step 10 was when problems started to arise. We needed access to four screws to continue the dissection process that we could see but could not get access to due to the torque adjusting mechanism. It took our group an extensive amount of time to realize that in order to remove the torque adjusting mechanism it was necessary to remove the truck of the drill. There was no obvious way to remove the truck of the drill aside from a small star screw that you could see when looking down the head of the drill (the part where the bits are put in). Even when this star screw was removed we were still unable to remove the chuck. After some research we realized that a reassembly of the drill was necessary to break the chuck free from its threads. Once the chuck of the drill was removed we could continue with the disassembly of the drill which continued to be straightforward.

Product breakdown

Subsystem Connections

The table below shows the connections by use of a matrix. The following is a guide to the subsystem connections in the following table:
Physical Connection: P
Mass Connection: M
Signal Connection: S
Energy Connection: E
For example, the motor and battery are connected by an electrical connection. Therefore, an E will show in the box shared by both the motor and battery.

Subsystem Connection Table
	Battery	Motor	Trigger	Casing	Chuck	Slip Gear	Gear 1	Gear 2
Battery		E	S	P
Motor	E		S	P	P
Trigger		S
Casing	P	P	P		P
Chuck		P		P
Slip Gear							P	P
Gear 1						P		P
Gear 2						P	P

Subsystem Analysis

Subsystem Analysis Table
Subsystem	Connection Type	Purpose	Picture
Battery	Electrical connection to electric motor through wires and a trigger	Provides electrical energy required of electric motor to do work
Electric Motor	Electrical connection from battery Mechanical (physical) connection to transmission through gears	Transforms the electrical energy from battery into mechanical energy for use through transmission
Transmission	Mechanical (physical) connection from electric motor, physical connection to chuck	Continues mechanical energy sequence. Changes speed of chuck based on a mechanical switch by trigger controlled by user
Chuck	Mechanical (physical) connection from transmission	Holds proper bit based on user's purpose, Final subsystem of Mechanical energy sequence
Casing	Physical connection to all subsystems	Holds every part in place in order to transform this series of subsystems into one complete unit that can be held comfortably by the user and be used efficiently.

GSEE factors involved in how the connections were developed:

Although not all the GSEE factors will play into the design of this drill the the following will address those factors that came into play for the design.

Economic issues: The drill appears to share the same body casing with other Black and Decker drills. This design allows for Black and Decker to use the same body design with other drills. This will allow the company to save money when it comes to manufacturing processes (for example, only needing to buy one mold for several drill bodies/casings). The gears also appear to be easily interchangeable on an assembly line and would use the same process outlined above. Environmental factors: Grease within the gearing housing design keeps rust from forming within the housing.

Subsystems which cannot be adjacent:

Although the internals of the drill tend to flow smoothly from one subsystem to the next in an orderly pattern, there is a subsystem which cannot be adjacent. The subsystem is that of Gear 1 and Gear 2. Although they are close to one another there is a Slip Gear in between them which allows for the change of speed with the drill. The drill would absolutely fail if these two subsystems were not separated.

Is there a reason for each subsystem placement?

Battery: The placement of the battery is on the bottom end of drill. The battery is external and allows for ease of replacement and recharging when necessary.
Trigger: The placement of the trigger is supposed to mimic that of a pistol. The designers decided that this grip would best suit the needs of the user and therefore placed the trigger in the traditional position to mimic the grip of a pistol.

Beyond these two the placement of the subsystems are implemented in a way that allow the battery to work. For example, the motor has to come before the chuck, or else the equipment will simply not work.