SAS

F06

BAE 417

Design of Machine Systems

Laboratory No. 1

Functional Analysis of a DEWALT Model DC759KA Cordless Drill/Driver

Introduction

            The DEWALT Model DC759KA Cordless Drill/Driver is designed to meet a number of performance requirements to be competitive in the marketplace.  Performance in this case is characterized by the ability to of this machine to drill holes in a variety of materials with drill bit up to 0.5 inches in diameter, or to install or remove threaded fasteners.  Some important performance parameters may include the overall torque capacity (N^.m) and speed (rpm) capacity of the cordless drill/driver and the ability of the battery pack to store sufficient energy (A^.h) to sustain operation of the cordless drill/driver for an acceptable period of time.  Operator comfort and ease of operation are also important features.  Obviously, the nature and variety of materials to be drilled may limit the utility of this device.

            This laboratory investigation is intended to guide students through a function evaluation of this machine.  Resources available to the student will include the machine itself, and an owner/operator manual.  In addition, instructional time in the lab will be devoted to the identification of various machine components and sub systems.      

Requirements

            For this laboratory exercise you will be required to identify the function and utility of the components and sub-system listed below.  For each components and sub-system you should provide a two to three sentence description of its function and/or utility.  Your lab report for this investigation will be limited to the submission of these descriptions.  This laboratory investigation will serve as a precursor to following laboratory investigations that will require a more in-depth treatment of several of these components.  Your lab report is due at the start of the following week's laboratory meeting.

Cordless Drill/Driver Sub-Systems and Components

1.0    Case

1.1    Ergonomics

1.1.1        Physical Size

1.1.2        Mass

1.1.3        Balance

1.1.4        Positioning of Controls

2.0    DC Motor

2.1    Torque Capacity

2.2    Cooling

3.0    DC Motor Control

3.1    On-Off Switch

3.2    Variable-Speed Control

3.3    Forward/Reverse Control

4.0    Drive

4.1    Gear Train

4.2    Two-Speed

4.4    Torque Adjustment

5.0    Chuck

5.1    Keyless Actuation

5.2    Size Limitations

5.3    Grip/Locking Requirements

6.0    Battery

6.1    Electrical Connector

6.2    Mechanical Locks

6.3    Capacity

7.0    Charger

7.1    Indicator Light

7.2  Recharge Interval

8.0    Overall Construction

8.1    Materials

8.1.1        Ploymers

8.1.2        Metals

8.2    Manufacturing Processes

8.2.1        Injection Molding

8.2.2        Die-castings

8.3    Fasteners

8.4    Serviceable Components