Brief for a long series drill

We are manufacturers and suppliers of drill bits to the industrial market. Our sales representative has had several requests for new type of long series drill bit.

Our existing long series drills can operate with no problem so long as the drill is frequently cleared (pecking). Many of our customers find this process time consuming and expensive.

If peck drilling does not occur then the flutes fill up with swarf and the drill jams. Depending on the size of the drill, it may snap in the material being drilled. This incurs further cost in replacing the drill, and wasting a piece of material.

This problem exists with all long series drills regardless of diameter. Long series drills are produced with both straight and tapered shanks. The new drill should be compatible with these existing fittings.

A new long series drill needs to be designed that will maintain the standard long series drill lengths. It must be able to drill out a piece of material in one single action.

Tasks

Identify and list all customer requirements.

The lecturer will offer further information on the problem.

2. Determine the major design parameters

Requirements

Hint: Underline or highlight the important information in the brief.

List what you think the customers requirements are. These will be found in the customer brief. There may be more or less than ten requirements.

After listing the customer requirements, consider what limitations and boundaries may be involved in the design.

This might include standards, materials, sizes, etc. Name the parameter and add a brief description

EG.

Drill diameters

The drills are supplied in metric and imperial sizes. Long series drills are supplied in metric sizes from 2mm to 30mm in graduations of 0.5mm, the imperial sizes are supplied from 1/8” to1½” in graduations of 1/16”. These existing sizes should be considered in the new design

Design requirements

Brief for a long series drill

We are manufacturers and suppliers of drill bits to the industrial market. Our sales representative has had several requests for new type of long series drill bit.

Our existing long series drills can operate with no problem so long as the drill is frequently cleared (pecking). Many of our customers find this process time consuming and expensive.

If peck drilling does not occur then the flutes fill up with swarf and the drill jams. Depending on the size of the drill, it may snap in the material being drilled. This incurs further cost in replacing the drill, and wasting a piece of material.

This problem exists with all long series drills regardless of diameter. Long series drill are produced with both straight and tapered shanks. The new drill should be compatible with these existing fittings.

A new long series drill needs to be designed, which will maintain the standard long series drill lengths, but will be able to drill out a piece of material in one single action.

1. Identify and list all customer requirements.

I.e. What are the customer requirements shown in the brief?

2. Determine the major design parameters

I.e. What are the limitations and boundaries of the design?

3. Produce a design specification for this problem

4. Ensure the design specification meets the customer requirements by describing how each aspect meets their needs

Section 1 Requirements

1. The customers are manufacturers of drill bits. (This may be relevant for the type of production).

2. Peck drilling is a time consuming process. The customer would like the hole to be drilled in one single process.

3. On the existing long series drills, if there is no peck drilling the flutes fill up with swarf and jam, this can result in breakage.

4. The problem exists in all long series drills regardless of its diameter.

5.  Long series drills are produced with both straight and tapered shanks.

6. Maintain the standard long series drill lengths

7. The new drill should be compatible with existing fittings

length   length                                  8

sha      ‹mm›    ‹mm)      Order code         each

6.00    115     175        02-3Z82             7.76

B.S0   115      175        02-3Z83             6.BB

J0.00  121     184        02-3284             9.K

10.z0  121      184        W-0705            t4A5

11.00  188      195       02W86             t2AZ

11.50  128     195        02-5287           13.01

12.00  134     20S       02-3288           15.05

12.50  1M       205       02-3208            T&64

13.00  134      205       024200            1Y.46    !

14.00  140     214        02-3292           ZIP        !

DIN 340 RN/BS 328

Flute geofrtetry

standard helix, right hand apiral pqjgt gngje

1 GB°

9urface treatment Bright: below mm, Y» Blue: mm, °/›e and above mgs

1 - 15mm, h e - 1in

Appllcetlon

General purpose long reach drills.

Metric

ZS0 .     02-SZ94          27.15

17.00  154     235       OS-S298               30•77    !

17.50  158     241       OS-M99            69•77

1B.00  158     241        0Z-3300           42.OZ

19.Q}  182      247        02-3502           ¥7.71

20,00  1B8     M4         02-3904           4SA0

21.00  171     261        02-3305           Sb.6S

ZZ.00  176      208       OZ-5S06               51.01

fractional

He    50         75          OS-B215                  1.S9slze lmmJ   ‹mm)        Order code            eBoh

1ength length                                     *••       w      sz          ss           az-sz1y                 1.eo

Siza  fmm)     (mm)      Order cade         oach     +@     66        100        02-3214              1.94

Section 2 - Parameters

1. Drill diameters

The drills are supplied in metric and imperial sizes. Long series drills are supplied in metric sizes from 1mm to 22mm, the imperial sizes are supplied from 1/16” to1”. The graduations between sizes vary, see the attached data sheet for exact diameters. These existing sizes should be considered in the new design.

2. Drill lengths

Drill lengths vary depending on the drill diameter. See the attached data sheet for long series drill lengths. The customer has asked that the existing drill lengths be maintained.

Section 3 – Design Requirements

3. Material used

The existing drills are made from HSS (high speed steel). The same material or a harder material should be considered if the improved product is a modified drill.

4. British standards for drills

BS 328 PART 1 Drills and Reamers Part 1: Specification for Twist Drills ISO 494:1975 Parallel shank twist drills - Long series

ISO 3291:1995 Extra-long Morse taper shank twist drills

ISO 10899:1996 High-speed steel two-flute twist drills -- Technical specifications

5. Existing Fittings

The new design must still fit in a standard drill chuck or morse tapers (No.1 to No.5). Also it should still fit in existing drill sharpening machines.

6. Coolant

In the existing drill the coolant is able to reach the cutting edge to provide cooling and lubrication. The new design should be no different.

7. Swarf Removal

The swarf must be constantly removed with no blockage. If the swarf builds up in the flutes then jamming can occur and this may result in the breaking of the drill.

8. Performance

The new design must be able to drill the hole in one operation, removing the need for peck drilling.

9. Operating environment

The operating environment will be the same as the existing drills. An industrial environment, where production rate is of paramount importance. The drill will be used repeatedly for long periods of time.

10. Maintenance

Maintenance of the drills will be limited to sharpening. This is usually achieved by placing the drill in a drill sharpener.

11. Cost

The new drill price must be comparable to the existing drills. To achieve this, research should be carried out on modern cost effective manufacturing techniques

Section 3

Product Design Specification

1. Title (this must be brief, unambiguous and informative).

2. List of Contents (this is to provide an easy way into the document for the reader).

4. Scope of the Specification (a clear concise description of the product including its role / function).

3. Foreword (a description of any relevant background information, in particular, the history of the project).

5. Definitions (any technical terminology, symbols, abbreviations and / or units of measurement that need to be defined).

possible markets (e.g. general public, armed forces, businesses etc.)

2 related specifications (e.g. British Standards, Codes of Practice, etc.)

3 maintenance programmes / spares (e.g. availability)

4 safety (e.g. fail safe devices / guards)

5 maximum price (e.g. selling / manufacture)

6 overall size, i.e. dimensions

7 power supply (e.g. battery, mains, generator)

8 appearance, ergonomics, style, surface finish, etc.

9 operating environment (e.g. temperature, corrosion, fatigue etc.)

10 working schedule (e.g. prototype, completion dates)

11  testing procedures (e.g. prototype tests, inspection)

12 performance

13 weight

14 noise levels

15 life – span

P.D.S.

Writing a Product Design Specification (P.D.S.)

Specifications are a means of communicating information from one person to another in a clear and concise form. This invariably involves the use of the written word, engineering drawings and sketches. Writing a specification is the best way of clarifying your ideas, and updating the specification regularly, will ensure that you remain on the required route as the project progresses. The specification is a statement of the characteristics that a design must possess in order to be a solution to an identified need.

The following is an extract from P.D. 6112 (Published Document 6112) produced by the British Standards Institute in 1967.

A specification is essentially a means of communicating the needs or intentions of one party to another.

It may be a user’s description to designer, of his / her requirements for purpose or duty. It may be a designer’s description to a manufacturer, of an embodiment of these requirements.

It may be a manufacturer’s detailed description to her / his operator, of the components, materials and manufacturing methods to be employed.

It may be a statement by a vendor describing suitability for a purpose to satisfy a need of a user or potential user. It may of course, be some, or all of these.

Writing a P.D.S.

In order to write a P.D.S. you must include the following, where appropriate:

6. Title (this must be brief, unambiguous and informative).

7. List of Contents (this is to provide an easy way into the document for the reader).

9. Scope of the Specification (a clear concise description of the product including its role / function).

8. Foreword (a description of any relevant background information, in particular, the history of the project)

10. Definitions (any technical terminology, symbols, abbreviations and / or units of measurement that need to be defined).

Quantifiable Aspects

In a specification certain items will be quantifiable, i.e. obtained by calculation, e.g. power, size, pressure, load, maximum temperature, etc.

Subjective Aspects

These include factors such as: potential market, appearance of product.

Objective Aspects

These include: safety standards, user skill, service requirements.

When preparing a specification, attempt to include the following:

1 possible markets (e.g. general public, armed forces, businesses etc.)

2 related specifications (e.g. British Standards, Codes of Practice, etc.)

8 maintenance programmes / spares (e.g. availability)

9 safety (e.g. fail safe devices / guards)

10 maximum price (e.g. selling / manufacture)

11 overall size, i.e. dimensions

12 power supply (e.g. battery, mains, generator)

8   appearance, ergonomics, style, surface finish, etc.

9 operating environment (e.g. temperature, corrosion, fatigue etc.)

16  working schedule (e.g. prototype, completion dates)

17  testing procedures (e.g. prototype tests, inspection)

18 performance

19  weight

20  noise levels

21  life – span

Specification Pitfalls

1. omissions, understatements, overstatements
2. poor communication, i.e. technical terms not clearly explained, all written communication must be clear and easily understood by both parties
3. insufficient use made of B. S. or Codes of Practice
4. duplication
5. plagiarism
6. vagueness / ambiguity / brevity
7. assumptions
8. poor grammar and spelling
9. poor presentation of log book / report
10. avoid subjective phrases, e.g. "adequate strength"
11. avoid phrases such as “not highest quality” and specify “optimum quality”
12. production of engineering drawings to unnecessarily tight tolerances

PDS Example Layout

Title:   Flux Capacitor in DeLorean

Foreword  I have always been interested in time travel and finally, I have the opportunity to design and develop a prototype time travel machine.

Scope of Specification: The machine must be a form of vehicle, as it is required

to travel at speeds in excess of 88 mph in order to warp time and thus achieving time travel. Using an aluminium chassis (based on Audi design) a turbo diesel fuel injected 98 cylinder engine will be obtained from a scrap yard and mounted to the chassis with connections to the flux capacitor. The flux capacitor will be manufactured from a specialist titanium alloy and engineering drawings will be produced prior to manufacture. The flux capacitor will have 1000 000 field windings thus allowing for high levels of induced magnetic flux.

Definitions: Flux Lines of force caused by a magnetic field.

Capacitor: An electrical component that stores a charge.

Space-Time Continuum: The connection between

space and time.

Unified Field Theory: Combination of all known forces

Theory of Relativity: States that: in order for time travel to occur, it would be necessary to travel faster than the speed of light.

Wormholes: Randomly occurring gateways through space and time.

Quantum Leaps: The movement of electrons when quantum energy is released.

Possible Markets: This product would attract attention from scientists and

historians wishing to verify events that have occurred and gain a better understanding of why they happened. The general public may also wish to use this to visit their families in the past. Schools would use this as a teaching aid (source: Bill and Ted’s Excellent Adventure).

Related Specifications: This product already will have to confirm to

various British Standards as it is a vehicle and will thus have to be road worthy. Ethical codes relating to the use of this vehicle will need to be developed in order that users are not reckless with the power they possess.

Maintenance: The flux capacitor will have to be regularly maintained and replaced every 1000 years of time travel. Availability of parts will be restricted due to the delicate nature of time travel.

Safety: Auto-return and cloaking devices will be mandatory in all vehicles, as this type of technology will have to be kept away from scientists in the past. After a specified period of time has elapsed, the vehicle will return with the traveller.

Maximum Price: Prices for this product will be in the region of £6

million, but by the year 2006, they will have dropped to around £99.95. Government grants are to be made available to interested parties (subject to status), this product will also be available for rent.

Overall Dimensions: The overall dimension will be 350 mm ´ 250 mm ´ 25 mm.

Power Supply: The power source will be renewable and makes use of recycled garbage to act as fuel. H2O, in the form of steam, will be the only by-product and as such, the engine will be classified as environmentally sound

Appearance Appearance: non applicable, the object is purely functional.

Ergonomics Ergonomics: non applicable.

Operating  The product in its operating environment would be affected by

Environment: ‘time corrosion’ and ‘temporal pressures’, however, the chassis will prevent any damage to the flux capacitor.

Work Schedule: The prototype will be completed by the end of 2005 and go into mass production by 2006. Please refer to Gantt Chart.

Testing: The testing procedures for the product will be based on British Standard BS 2364; Temporal and Time Distortions Vehicles Mandatory Criteria (TATMAC).

Performance: Performance of this product will mean that it has to be

able to travel 64 million years in either direction (past or future), at speeds no greater than 186 299 miles per second with only minor services after every 3000 miles.

Weight: Weight is an important consideration and must be kept as low as possible because as the speed of light is approached, the mass of the vehicle will increase. The flux capacitor therefore, will be manufactured from the lightest possible materials in order to keep weight at a minimum.

Noise Levels: Noise production levels from the vehicle will not be problematic as the component utilises anti-sound generators, similar to Stealth Bombers, approximately Db » – 0 .5 (this sounds like hmmmmmmmm).

Life Span: As mentioned previously, the life span of the flux capacitor is that of 1000 years of time travel at which time it will need to be replaced.

Drill Related Definitions

Axis: The imaginary straight line which forms the longitudinal center line of the drill

Back Taper: A slight decrease in diameter from front to back in the body of the drill Body: The portion of the drill extending from the shank or neck to the outer corners of the cutting lips

Body Diameter Clearance: That portion of the land that has been cut away so it will not rub against the walls of the hole

Built-Up Edge: An adhering deposit of nascent material on the cutting lip or the point of the drill

Cam Relief: The relief from the cutting edge to the back of the land, produced by a cam actuated cutting tool or grinding wheel on a relieving machine

Chip Breaker: Nicks or Grooves designed to reduce the size of chips; they may be steps or grooves in the cutting lip or in the leading face of the land at or adjacent to the cutting lips Chip Packing: The failure of chips to pass through the flute during cutting action

Chipping: The breakdown of a cutting lip or margin by loss of fragments broken away during the cutting action

Chisel Edge: The edge at the end of the web that connects the cutting lips

Chisel Edge Angle: The angle included between the chisel edge and the cutting lip, as viewed from the end of the drill

Clearance: The space provided to eliminate undesirable contact between the drill and the workpiece

Clearance Diameter: The diameter over the the cut away portion of the drill lands

Core Drilling: Core drills are 3- and 4-fluted cutters used to enlarge previously drilled core or pierced holes.

Counter Bore: Used to enlarge a portion of a cylindrical bore hole.

Counter Sink: A cutter that makes a cone-shaped enlargement at the end of the hole. Crankshaft or Deep Hole Drills: Drills designed for drilling oil holes in crankshafts, connecting rods and similar deep holes; they are generally made with heavy webs and higher helix angles than normal

Cutter Sweep: The section formed by the tool used to generate the flute in leaving the flute Deep Hole Drilling: Any hole longer than four times its diameter is considered a deep hole. Double Margin Drill: A drill whose body diameter clearance is produced to leave more than one margin on each land and is normally made with margins on the leading edge and on the heel of the land

Drift: A flat tapered bar for forcing a taper shank out of its socket

Drift Slot: A slot through a socket at the small end of the tapered hole to recieve a drift for forcing a taper shank out of its socket

Drill Diameter: The diameter over the margins of the drill measured at the point

Exposed Length: The distance the large of a shank projects from the drive socket or large end of the taper ring gage

Flat (Spade) Drill: A drill whose flutes are produced by two parallel or tapered flats

Flutes: Helical or straight grooves cut or formed in the body of the drill to provide cutting lips, to permit removal of chips, and to allow cutting fluid to reach the cutting lips

Flute Length: The length from the outer corners of the cutting lips to the extreme back end of the flutes; it includes the sweep of the tool used to generate the flutes and, therefore, does not indicate the usable length of the flutes