The document summarizes the reverse engineering process of a cordless drill. It includes observations of the drill's functions and specifications. The discussion provides an exploded view diagram, bill of materials list, and tree diagram. Functional analysis techniques are used to analyze how the system works. Key components include the battery, DC motor, gearbox, and chuck. When the trigger is pulled, the battery provides electrical power that the motor converts to rotational force, which is transferred through the gearbox to spin the chuck and drill bit.

1. 2016
By:
Molham Masri
Mahmoud Mandow
Shadi Saffour
Supervisor:
Eng. Ahmed Ateyat
5/31/2016
Cordless Drill

2. 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

3. 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

4. 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.

5. 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

6. 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

7. 6
Discussion:
Exploded View:
Figure 3: Exploded View

8. 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

9. 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

10. 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

11. 10
Math Equations:

12. 11
Where:
Table 3: Symbol Abbreviation

13. 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

14. 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

15. 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