2016

By:

Molham Masri

Mahmoud Mandow

Shadi Saffour

Supervisor:

Eng. Ahmed Ateyat

5/31/2016

Cordless Drill

1

Table of Content:

1. Introduction…………………………….…….……………………...3

2. Prescreening.………………………………………………………...3

3. Observation..…………………………………………...……………3

3.1. Function of Battery Drill………………………….………………………..3

3.2. Specifications.……………………………….……………………………..4

3.3. Black Box Diagram…………………………….…………………………..4

3.4. Block Diagram…..……………………………...………………………….5

3.5. Performance Test and Results………………………….…………………..5

4. Discussion………………………………….……………….………..6

4.1. Exploded View…………………………………….………………………..6

4.2. Bill of Material (BOM)……………………………….…………………….7

4.3. Tree Diagram……………………………………….……………………….8

5. Analysis……………………………………….……………………...9

5.1. Functional Analysis System Techniques (FAST)…………………………..9

5.2. Math Equations…………………………………………………………….10

5.3. How the system works……………………………………………………..12

6. Conclusion…………………………………………………………..14

7. References………………………………………………………..…14

2

Table of Figures:

Figure 1: Block Box .................................................................................. 4

Figure 2 : Block Diagram .......................................................................... 5

Figure 3: Exploded View .......................................................................... 6

Figure 4: FAST .......................................................................................... 9

Figure 5: Battery ...................................................................................... 12

Figure 6: DC- Speed Switch.................................................................... 12

Figure 7: Motor........................................................................................ 13

Figure 8: Gear Box .................................................................................. 13

Figure 9: Rotate Chuck............................................................................ 13

Table Contents:

Table 1: Bill of Material ............................................................................ 7

Table 2 : Tree Diagram ............................................................................. 8

Table 3: Symbol Abbreviation ................................................................ 11

3

Introduction:

The power hand drill (cordless drill) is a tool used with drill bits to create

or enlarge holes in different kinds of materials (e.g. aluminum, plastic,

wood) or to link a various materials together using screws.

A cordless drill is an electric drill which uses rechargeable batteries. These

drills are available with similar features to an AC mains-powered drill.

A power drill is comprised of two sub-systems; mechanical and electrical.

The mechanical subsystem is made up of components whose purpose is to

transfer, translate or apply forces. The electrical subsystem contains

components that supply and control power flow.

Reverse Engineering for the Product

Prescreening:

The product is a battery hand drill (cordless drill).

We selected this product because some reasons:

- In order to decrease the cost.

- Market needs.

- In order to try to increase the torque.

- In order to increase the battery capacity.

Observation:

Function of battery drill:

Used for making holes in different kinds of materials (e.g. aluminum,

plastic, wood), or to link a various materials together using screws,

Powered by battery charger.

4

Specifications:

Weight = 0.9 kg (without battery)

Drilling diameter = (1.5 -10) mm.

Torque = 5.8 N.m (6 positions)

No-load speed = 550 rpm (reversible)

Frequency =50-60 Hz

Material (plastic)

Cost = JD 20

Rechargeable battery = 1.2 V

Charger = 230 V/9V – 400 mA

Charging time = 5 hours

Black box diagram:

Battery Drill

Battery power

Finger switch

Hand

Insert bit

Human force

Noise, Vibration

Drill rotation

Tightening screw

Heat

Make hole

Figure 1: Block Box

Bit rotation

5

Block diagram:

Performance Test and Results:

We operated the drill to do a performance test, where we checked the drill

on different torques and positions, by making holes on the wall and also

install the screws of various sizes and shapes, and its performance was

very good.

Figure 2 : Block Diagram

6

Discussion:

Exploded View:

Figure 3: Exploded View

7

Bill of Material (BOM):

Table 1: Bill of Material

No. Part Name

1 Housing Set Part 1

2 Housing Set Part 2

3 Body Screws (9 Pcs)

4 Chuck Screw

5 Keyless Chuck

6 Clutch Dial or Collar

7 Spring

8 Washer A

9 Gear Case

10 Steel Ball (16 Pcs)

11 Ring Gear

12 Plastic Gear (3 Pcs)

13 Washer B

14 Pinion

15 Steel Gear (3 Pcs)

16 Washer C

17 Motor Dc 7.2 V

8

Cordless Drill

Input Powers

Swicth Power

Accept Power

Transmit Power to

Motor

DC Motor

Generat electrical

Power

Convert Electrical Power to

Mecanical Power

Housing Set

Gathering Parts

Safty

Handle Drill

Input on/off Signal

Accept on/off Signal

Trasmit on/off Signal

Rotate Shaft

Convert Electricity Rotation

Spin Shaft

Rotate Gears

Change Lever

Reverse Shaft Rotation

Lock Switch

18 Wires

19 Controller

20 Change Lever

21 Drill Bit

22 Rechargeable Battery

23 7.2V Charger

24 Dc-Speed Control Switch

Tree Diagram:

Table 2 : Tree Diagram

9

Analysis:

Functional Analysis System Techniques (FAST):

The figure below shows the FAST approach to show how the product

main and sub functions are related together.

Figure 4: FAST

10

Math Equations:

11

Where:

Table 3: Symbol Abbreviation

12

How the system works:

Considering the cordless drill driver like an electrical circuit. Every time

we pull the speed control trigger we are completing the circuit, allowing

power to flow through the tool.

Here we have the steps of how the cordless drill works:

Step 1 – Battery:

Potential electrical energy in our

rechargeable battery 1.2V.

Step 2 - Dc-Speed Control Switch:

When we pull the Dc-Speed control

switch, another switch on the other side

(inside the tool’s casing), conducts

electricity from the rechargeable battery

to the motor.

Figure 5: Battery

Figure 6: DC- Speed Switch

13

Step 3 – Motor:

A motor DC 7.2 V converts the

battery's electrical energy into

mechanical energy giving the

rotation required to turn the chuck.

Step 4 - Gear box:

This power is a combination of torque

(turning force) and speed and is

transferred to the chuck via the

gearbox.

Step 5 - Rotate chuck:

The motor’s power causes the chuck to

rotate, allowing the drill driver to drill

holes and drive screws (with the required

drill bit or screwdriver bit).

Figure 7: Motor

Figure 8: Gear Box

Figure 9: Rotate Chuck

14

Conclusion:

We know how to make reverse engineering for any device.

We applied all steps for reverse engineering.

We break the fear barrier with any new device, and we can make

disassemble in easier than before.

After disassembly process and find out all the parts, we can now we

manufacture this product in our country to temper shipping costs and

import and we export it and so is sold at a cheaper price by the people of

the country.

References:

http://www.ereplacementparts.com

http://www.esc-ltd.co.uk

http://www.wonkeedonkeetools.co.uk

How Things Work' by the Editors of Consumers Guide, Publishers

International, 1990

Fundamentals of Machine Component Design by Robert Juvinall and Kurt

Marshek, J. Wiley, Second Edition, 1991

Small Appliances Servicing Guide by Robert Scharff McGraw - Hill, Inc.

(c) 1976