Gate 2 - Group 4

Gate 2: Product Dissection

Purpose

In Gate 1 we organzied our group, researched our product (the DeWALT DW511 Hammerdrill), and set the groundwork for the next step of our analysis; the dissection. Bringing us to Gate 2, we now begin the dissection process, where we follow our plan to take apart the product and learn more about its functionality and design. Displayed below in this gate, you will find a clear and easy-to-read, step-by-step process of how we completed this task. By providing a clear description, tools used, and images for each step, we ensure that any reader will be able to dissect this part following our directions. Following our disassembling process, we also documented the knowledge we acquired throughout this stage of our project, answering questions about ease of disassembly and the functionality/arrangement of subsystems.

Project Management: Preliminary Project Review

In Gate 1 we established a management system and work proposal for this project, along with known challenges faced, and possible future challenges we expected to come across. We were correct with reguards to some aspects, but quite off with reguards to others. Below, we provided a quick assessment of these different factors, and how our expectations were or were not reached.

Work Proposal

Organization of Disassembly

• Our organized plan for disassembly was beneficial. By taking our time and documenting each step of the procedure, we were able to create a clear set of step-by-step directions. In Gate 1 we said "Each part removed will be bagged and numbered. All parts will be recorded with their corresponding number and the parts function". We did exactly that, along with taking pictures for each step. Once the disassembly was completed, we were able to align the indivual parts for a clear exploded view.

Required Tools

• We made the estimations that disassmbly would require Philips and flathead screwdrivers, an allen wrench, and a knife; all of which were incorrect. Tool requirements ended up only being (other than the use of our hands) three Torx screwdrivers: the t-10, t-15, and t-20.

Required Time For Dissection

• Guessing it would take us 2 hours to complete the dissection, we overestimated by an hour. It took us just under 60 minutes to seperate the drill into all of its components, and that includes time for documentation of each step. If there was a rushed need for its disassembly, we expect the procedure could be accomplished in under a half hour.

Management Plans

Group Meeting Times

• This factor of the project has proved to provide the most challenges to our group thus far. We set original meeting times as a rough estimate for Mondays and Fridays before class, but some members have other classes, preventing them from making it. All four members live locally at home, and have very limited availability due to other homework, and mostly, work. Since the start of this project we have only successfully met one time where the group was in its entirety (excluding directly before or after class). We have worked hard to overcome this challenge, but it is inevitable. Our only solution has been to meet in seperate sub-groups on occasion, and then discuss our accomplishments via texting, internet, and in class.

Group Capabilities

• We stated that some of our group capabilities included being "mechanically inclined" and there was some prior electrical experience. This held true and was benficial during the disassembly because it made the procedure easier, and allowed us to understand the functionality of the part, and exactly how the indiviual components inside interact with one another.

Group Shortcomings

• Prior to this project not a single member had any Wiki-documenting experince or knowledge. As a solution, we have all spent considerable amounts of time researching and learning how to use this program.
• We have limited electrical component knowledge, which we feared would hinder our understanding of the complete functionality of the hammerdrill. However, we collectively were able to understand and figure out the purpose of each part and how it worked.
• The closest thing to technical communication any group member has, is from lab reports written for other classes. This project is helping develope our skills in this area.

Expected Challenges

• In Gate 1 we stated that "the group does not believe there will be any challenges faced during the disassembly and reassembly of this product". Although this held true for the disassembly, it does not necessarily hold true for the reassembly. During the disassembly, we had to disconnect some wires connected to the motor. Since we aren't very experienced in assembling electronics, this will provide a challenge to the group when it comes time for reassembly. If we find it imperative to reconnect the wires for future product use, we will execute the option of having an experienced electrician aid this part of the reassembly.

Product Archaeology: Product Dissection

The DeWalt DW511 Hammerdrill was relatively easy to dissect, taking under an hour to take apart while documenting each step along the way. Although we did not really encounter any challenges, some parts required a little more force to be removed than others (telling us that the manufacturers did not intend for these particular parts to be easily disassembled). Shown below is the step-by-step process we took to disassemble our product.

Difficulty Scale

Difficulty Level:	Required tools and time:
1	No tools, takes a short amount of time, quite intuitive.
2	No tools, takes a decent amount of time, less intuitive.
3	Requires a tool, takes a short amount of time, quite intuitive.
4	Requires a tool, takes a decent amount of time, less intuitive.

Step #	Descriptive Action	Tool Used (If Any)	Difficulty	Image Guide
1	Remove detachable support side handle from tool, by twisting handle in a counter-clockwise motion to loosen its grip.	none	1
2	Continue twisting the handle until it completely unscrews and seperates from the lag bolt/clamp.	none	1
3	Remove the 1/2" x 4" lag bolt from the circular clamp by simply sliding it out.	none	1
4	Remove three (3) screws from back of drill handle.	Torx t-15 screwdriver	3
5	Remove the rear casing from the back of the handle.	none	1
6	Remove front two (2) screws from the top of the gearbox casing. (front end of drill)	Torx t-15 screwdriver	3
7	Remove front screw from the bottom of the gearbox casing. (front end of drill)	Torx t-15 screwdriver	3
8	Slide the chuck* assembly and gearbox casing off from the front end, revealing the gearbox assembly.	none	2
9	Remove the gasket ("o-ring") from the gearbox assembly.	none	1
10	Remove relatively short-lengthed shaft (has two gears located on it) from the gearbox assembly.	none	1
11	Remove the single ball-bearing from the rear end of the shaft removed in the previous step. (step 10)	none	1
12	Slide the Hammer/Drill operation selector switch out from the top of the drill.	none	1
13	Remove two (2) screws from the rear end motor.	Torx t-10 screwdriver	4
14	Remove two (2) outside parts of the motor assembly.	none	2
15	Slide the trigger assembly/electrical power cord out from the handle casing.	none	1
16	Remove the positive (+) and negative (-) wires for the motor.	none	2
17	Remove the positive (+) and negative (-) wires for rear motor power terminals. (reverse)	none	2
18	Remove the trigger assembly/ electrical power cord from the entire assembly.	none	1
19	Slide the motor shaft out from the motor assembly.	none	2
20	Remove the black plastic collar from the frontside of the motor housing.	none	2
21	Remove the two (2) coarse-thread screws from the inside of the motor housing.	Torx t-10 screwdriver	3
22	Remove the outside of the motor from the casing.	none	2

• The chuck assembly is an inseparable part of the drill. Our group has tried everything from heating the barrel, to using an impact wrench with a torx bit and even simply using a torx screwdriver to try and loosen the torx screw located in the barrel of the chuck. The years of use this drill has been put through has actually helped tighten the screw through vibrations and by the counter thread of the screw itself. Two T20 screwdrivers were ruined trying to loosen this screw.

Product Dissection Assessment

Disassembly Ease

• In order to define a difficultly scale for each of the steps in our dissection, we decided to rank the level of difficulty from 1 to 4, 1 being the easiest and 4 being the hardest (difficulty scale is defined above, just before the dissection steps table). The scale we defined takes into account the amount of time, tools, and thought process required to complete each step. Overall the whole dissection process was quite easy to complete besides the dissection of the chuck which we were unable to do.
• In conclusion, we were able to dissect each part and assembly of the hammerdrill. We found little difficulty in doing so and we found there was no part of the product unintended to be disassembled, besides the chuck. While the chuck may be intended to be dissected, we were unable to do so because of the age and major wear on the drill.

Subsystem Connections

The internal components in the system are connected in a way which allows for the device to function properly as designed. There are multiple subsystems required which if absent, the drill would cease to perform as intended.

Power cord connection to the trigger assembly

• Physical connection: The power cord plug is connected to the trigger assembly by wiring. Two (black and white) wires extend from the plug connecting to the positive and negative terminals on the trigger assembly.
• Energy connection: When connected to an outlet, the power cord supplies an electrical energy flow to the trigger assembly through the wires housed to the trigger terminals.
• Signal connection: In terms of the signal, the user inputs a force on the trigger releasing a signal to the mechanism to allow electrical flow from the power cord to the trigger and into the motor.
• Mass connection: No mass connection is made.
• Importance and performance influence of the connection: The user controls the trigger to allow the power cord to transfer electrical energy from the outlet it is plugged into, to the trigger which then transfers this energy to the motor. Without this connection there would be no energy input into the system and therefore the user would be unable to use or control the device.
• Global connection influence: Based on the plug on the power cord, the drill can only be used in North America due to the outlet required.
• Societal connection influence: For safety, durable wiring is used so it will not tear and people won’t get electrocuted.
• Economic connection influence: Parts are housed and protected on the inside of the drill so plastic is used to minimize cost.
• Environmental connection influence: Due to the electrical cord, battery disposal is not needed (alternate electrical energy source).

Trigger assembly connection to the motor

• Physical connection: The trigger assembly is connected by two wires to the positive and negative power terminals on the motor. This allows electrical energy to be transferred into the motor. The terminals are connected to the motor by screws.
• Energy connection: The electrical energy from the power cord which was transferred to the trigger assembly is then sent to the power terminals connected to the back of the motor, powering it.
• Signal connection: The users input force on the trigger signals the trigger assembly to transfer electrical energy to the motor so it can be powered.
• Mass connection: No mass connection is made.
• Importance and performance influence of the connection: The transfer of energy must be regulated from the trigger by the user so the drill will only run when the user wants it to. The motor cannot be powered without this function.
• Global connection influence: The region of manufacturing must allow for the availability of the motor parts and plastics integrated into the system.
• Societal connection influence: The user directly interacts with the trigger therefore it had to be designed ergonomically to fit the users fingers.
• Economic connection influence: Mass manufacturing parts for the trigger and motor must have been taken into account. The parts more widely available were used.
• Environmental connection influence: Whether or not the motor and plastics used can be recycled if they must be replaced.

Motor assembly connection to the gearbox assembly

• Physical connection: The motor assembly is connected by the shaft and ball bearing to the gearbox assembly. The gearbox contains a set of 3 gears and an additional shaft.
• Energy connection: The electrical energy transferred into the motor creates rotational energy which turns the gears in the assembly.
• Signal connection: The motor can only be powered through the user input of the trigger signaling energy transfer.
• Mass connection: No mass connection is made.
• Importance and performance influence of the connection: The function of this sub system connection is required to convert the electrical energy into rotational energy of the gears through the shaft.
• Global connection influence: The availability of the gears and gearbox integrated was taken into account.
• Societal connection influence: The noise of the motor and gearbox turning must have met the standards of the user and stander-by.
• Economic connection influence: Mass manufacturing and wide spread availability of the motor and gearbox was made to insure replacements are available and it is cheaper to buy in mass quantities.
• Environmental connection influence: The gears, motor, and gearbox must be recycled if necessary to replace. Recyclable materials must be used to reduce waste.

Gearbox assembly connection to the chuck assembly

• Physical connection: The small shaft and gears connects to the chuck assembly which in turn rotates the drill bit.
• Energy connection: The rotational energy of the gears and shaft is transferred to the chuck assembly housing the drill bit so it can be rotated as well.
• Signal connection: The users input force on the trigger sends a signal to transfer converted rotational energy from the motor to the gears and shafts driving the chuck to spin the drill bit.
• Mass connection: No mass connection is made.
• Importance and performance influence of the connection: Without this connection the drill bit housed by the chuck would not rotate. Therefore causing the system to be useless.
• Global connection influence: Availability of parts in the region of manufacturing.
• Societal connection influence: Ease of assembly in changing out bits in the chuck by the user.
• Economic connection influence: Mass manufacturing of the gearbox and chuck were used in order to allow for replacement parts and low initial costs by ordering mass quantities.
• Environmental connection influence: The chuck and gearbox must be recyclable in order to reduce pollution and waste.

Arrangement of subsystems

The overall subsystem connections are arranged in a way in order to function properly and allow for the hammerdrill to work as intended with ease. The power cord is connected to the trigger assembly which connects to the motor forming a bond to the gearbox assembly and the chuck. They are all connected in a series arrangement and will only work in the order described. If any of the systems are reversed or are not in an adjacent series arrangement, the hammerdrill will no longer function.