cw fab guide

7/30/2019 CW Fab Guide

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CURTAIN

WALL

FABRICATION

DRAWING

GUIDE

By Edgardo M. Bernardino


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Introduction 1

1. The Basic 32. Dimensioning and Call-outs 143. Project Specifications 354. Standard Fabrication Drawing Library 395. Todays World 416. Fabrication Samples 437. Reasons Why Mistakes are Committed 638. Helpful Tables 709.

References and Further Reading 74About the author 00


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CURTAIN WALL FABRICATION DRAWING GUIDE

By Ed Bernardino

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INTRODUCTION

The purpose of this book is to guide curtain walldesigners and fabricators alike to be familiar with theproper presentation of fabrication drawings. In myexperience in different curtain wall companies here inthe Philippines and in the Middle East they have theirown different ways of presenting such drawings. Thisis more frequent in the Middle East considering the

different nationalities working there, the differenteducational background, the different engineeringstandard, and most importantly the labourers who didnot even know how to interpret a working drawing.

This confusion were even enhance by the differentexperience of technical personnel like; technicalmanager, design manager, design project manager,

design team leader, design supervisor, seniordesigner, draftsmen, and even production managerwho brought their own knowledge which is not evenclose to the companys standard. For example, whena new design project manager comes to a company,she/he adopted his/her standard disregarding theexistence of companys standard.

This practice is very disturbing because it affectseverything from design, quality assurance/ qualitycontrol and production department. Of course eachhas his own agenda; more specifically for their owndepartments benefit because they find difficulty inadopting the established guidelines.

By the way, I will not argue nor contradict what theexisting standard practice of individual companies or


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the company where you are presently working asthey have their own way of presentation. Nor ask you

to adopt what is being discussed in this book.Nevertheless, because of my experience where manydrawings were not understood in the production,simplicity is the best logical approach.

Those who have knowledge in architecture andengineering they have different way of presenting

fabrication drawings. (There are those who present inarchitectural way, civil, electrical, mechanical orsanitary way of presenting).

Although, there is no harm in adopting eitherarchitectural, civil, electrical, sanitary or mechanicalpresentation the burden lies on the designer on howto present the drawings to be understood by an

ordinary labourer who do not have any background,even to know how to read a simple working drawing.

In this book the author will not fully explain about thedifferent types of section view such as; full, half,removed, revolved and broken-out section because Ireally want to have a conventional or simple

presentation were as much as possible abolishsectional views.

To the ordinary workers section views might evenconfuse them especially if there are so many sections.Besides, many assembly and part drawings in acurtain wall fabrication can be simplified accordingly.

By the way those who believe that side view is similarto section view. This take place when a profile or die


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is interpreted as a section. True, it is indeed a sectionbut not in the orthographic or pictorial presentation

jargon as it has own definition of the word section(views). A view is called a section view when a cuttingplane line is introduced to the top, front or side views.

1. THE BASIC

It is a norm that a mechanical method in presenting

fabrication drawing is the most conventional way ofpresenting. This is simple because designer is notcompels to show all the five (5) views illustrated inFigure 1.1 below.

FIGURE 1.1-ORTHOGRAPHIC PROJECTION PRINCIPLES

As shown above, projection or extension lines help

explain the relationship between each view. Slottedholes can be easily identified on how it is displayed,


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where it is located and how it is associated with eachother. Nowadays however, due to computer aided

design drafting these lines are sometimes removedfor clarity.

This kind of presentation is also called third angleprojection. If fabricator will learn this simple principle,designer will no longer find difficulty in producingfabrication drawings that can be understood in the

production line.

Before going any further it is vital to explain thedifferent between the two (2) types of projection; thefirst angle projection and third angle projection. Forbetter understanding and guidance for draftsman andfabricator alike let me start by showing the projectionsymbol, as shown in Figure 1.2 and 1.3.

FIGURE 1.2 FIGURE 1.3

Usually, either one of these symbols is added tocompleted drawing to avoid directional viewing arrow.

However, this becomes useless if the reader do notunderstand how it is oriented and what thefundamental differences between first and third angleprojection system is.


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The current British and ISO standards accept bothsystem but they should not be mixed on the same

drawings. In short, in preparing a complete workingdrawing decide which of the two you want to use.

Ironically, in several companies which I worked inUnited Arab Emirates only one (1) is following thisstandard. Most of the time, they combined the twosystem making the interpretation difficult especially to

the fabricators.

Instead of using the angle projection, most of thedraftsmen rely on the orientation arrow. See Figure1.4 as example.

FIGURE 1.4-VIEWING USING ORIENTATION ARROW

The major mistakes of relaying to the so calledorientation viewing arrow is; most of the time the

aforementioned angle projection is violated. Thisviolation brings confusion to the drawingpresentation. For example the draftsmen place the


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arrow wherever he or she wants because he/ shewant to show one or three portions of the object,

there might be a possibility of mixing the two angleprojection system which is not allowed by ISOprocedures.

Sometimes this also conflict with the addition ofcutting plane line, where its objective totally deviatefrom what is intended in the sectional view.

As an experienced draftsman or designer, you mustbe aware and fully conversant in all forms oforthographic and pictorial projection thus able toproduce a complete fabrication drawing without doubtor ambiguity relating to interpretation. Taking intoaccount that the end user is not as qualified as youare (in interpreting what you did), always put your

shoes into the workers.

As a fabricator, I think this is the right time for you tostudy this angle projection rules for your own benefit.

The following illustration describes more on how theorientation of the two systems works. See Figure 1.5

to Figure 1.8.

FIGURE 1.6-THIRDANGLE PROJECTION

FIGURE 1.5-FIRSTANGLE PROJECTION


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Notice the difference between the two. On the firstangle projection (Figure 1.7) the block is turned to

the left while the third angle projection (Figure 1.8) isturning to the right yet both present the top view ofthe block.

FIGURE 1.7-FIRST ANGLE PROJECTION

FIGURE 1.8-THIRD ANGLE PROJECTION


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(In the course of my examples, as much as possible Iwill use the third angle presentation as it is similar to

the standard orthographic projection).

Let us go back to our objective which is to reduce thenumber of views to save drafting time not only duringthe design stage but during the revision ormodification. Looking back to Figure 1.1, removingone side view will not jeopardize the fabrication

drawing. See Figure 1.9.

FIGURE 1.9 FOUR VIEWS PRESENTATION

Can I still remove one or two views withoutabandoning the objective of complete workingdrawing which stressed that the reader or end userneed not to go back to the designer to ask anyquestion regarding the drawing? A complete workingdrawing thoroughly explains what is to be done and


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will stick to it. Before removing a view let me explainfurther another principle in drawing presentation.

In college days one (1) view with center line explainthat the object is a rod or cylindrical or conical as thecase maybe (See Figure 1.10). However, to anordinary worker they will not understand this kind ofobject unless one (1) view will be added see Figure1.11 or a call-out which identifies that this is indeed a

rod like in Figure 1.12.

Figure 1.11 is the most acceptable to most workerswith limited technical background but Figure 1.12 ismore convenient by just adding size and material ofpart. For purposes of simplification, Figure 1.13 ishighly recommended however, other might misreadthe intent especially if revolved section is notexplained to the end users.

FIGURE 1.10OBJECT WITH CENTER

FIGURE 1.12 - CALLOUT IS ADDED

FIGURE 1.11 - SIDEVIEW IS ADDED

FIGURE 1.13REVOLVED SECTION

IS ADDED


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Let me discuss the Cutting Plane Line (CPL) andSection Line (SL); when to use it or not to use it. In

the drawing samples above, there is no need to useCPL as these are very simple object. However, whenthe object is complicated and end user cannot figureit out then CPL and SL is required.

Again, as the author experience, most of thecompanies in the Middle East include cutting plane

line (CPL) and section lines (SL) in the fabricationdrawing without understanding the primary purposeof doing so. They do not have the idea that followingonly the principle of orthographic projection is enoughto make a fabrication drawing. Now, when there arecomplicated areas where a plain view cannot fullyidentify such areas, then it is necessary to providecutting plane line and section line so fabricator can

understand the drawing. Similarly, auxiliary view orhelping view can be added if required.

When using CPL the designer shall be aware of therules such as;

1. When the CPL passed through a bolt, screws,keys and the likes, section line shall not beshown on these items. As shown on Figure

1.14.

2. When two (2) or more separate parts were cut,direction of section line shall be observed to

characterize that they are separate with each

other. (Also in Figure 1.14).


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Since this discussion focus on simplicity, there is

no need to elaborate the different section line

symbol of every material but rather use the

standard symbol.

FIGURE 1.14 CUTTING PLANE LINE AND SECTION LINEAPPLICATION

The drawing as shown in Figure 1.14, the cuttingplane line is passing thru two (2) bolts. In thisexample, the designer intent is to display the holesand that is the reason why the CPL is drawn in suchdirection. It is therefore the responsibility of the

designer where he intent to place the CPL, with anintention to clear up doubts that might arise whenfabricator will start the production.

Again, if it is not required do not provide cutting planeline and section views.

You will also notice that bolts were not section asstated in rule number 1. Similarly, two (2) parts of the


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assembly were section in different direction indicatingthat these are separate parts.

There are additional rules on this subject, but I ratherfocus on the above in order not to complicatematters, since our goal is to convey to the workers inthe simplest way possible in preparing a fabricationworking drawing so they can understand easier.

I will no longer venture in explaining the differentkind of section views like; full, half, removed,revolved and broken-out as this might be beyond thecomprehension of the end user, the workers. Maybethe more additional infusion of technicalities into ourfabrication drawing, the more they will be confused.Again, I wish to restate my position to have a simpleeasily understandable fabrication drawing

presentation.

Let us go back now to the simplification of drawing.As previously discussed, eliminating views andreducing to the minimum is beneficial to designer,fabricator and other end users. Let us use the samechannel shown on Figure 1.1 in our discussion.

FIGURE 1.15 THREE VIEWS PRESENTATION


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You will notice that the orientation of the side view onFigure 1.15 was change if you compare it against

Figure 1.1. Actually, it doesnt matter if it wasoriented differently for as long as it defines the partto be fabricated. Since I wish to reduce the views Ioriented it in such a way that all the informationrequired by the fabricator is clearly explained in thegiven views. In this position the slotted holes are allhighlighted in three (3) views only while in Figure 1.1

& 1.9 you need extra view(s) to explain the holeslocation.

I am leaving the designer to his own judgmentwhether to adopt this presentation or not. Maybethere are limitations in using this, such as; space,company guidelines and other reasons.

Can I remove another view? In this example nomore! Otherwise it will just complicate things.However, if the slotted holes are align then it can bepresented in two (2) views. See Figure 1.16 below(from this point, projection lines will be removed forpresentation clarity).

FIGURE 1.16 TWO VIEWS PRESENTATION


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As we go along, all the data require for the completeworking drawing like call-outs, dimension lines,

finishes, material and other relevant topics will bediscuss thoroughly.

2. DIMENSIONING AND CALL-OUTS

Dimension and call-outs are very importantinformation in a fabrication drawing otherwise it will

be impossible for the fabricator to manufacture anobject. Dimensions might be in English of Metricsystem depending upon which part of the world youare, or the company you are working. Although mostof the countries are adopting Metric system there aresome companies who still use English system. In theMiddle-East where I worked before, they are usingMetric system, so sample drawings in this book willadopt Metric system.

Likewise; I wish to emphasize the importance of call-outs and dimension text which shall be legible enoughso anybody who read drawings can clearlyunderstand what are being describe and dimensioned.Many designers ignore the significance of this,

although there is already guideline for the minimumtext height in a particular drawing as stated in thecompany drafting manual, in case they have one.

In order to produce a good professional standarddrawing, it is important to observe the dimensioningstandard as described in British Standard 8888 which

covers all ISO dimensioning rules.


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For our reference, below is the DimensioningPrinciples from the Manual of Engineering

Drawing by Colin H. Simmons and Dennis E.Maguire. (Please compare this to your OfficeDrafting Manual and if there is any deviation applyyour company standards).

1.Dimension and projection lines are narrowcontinuous lines 0.35mm thick, if possible,

clearly placed outside the outline of thedrawing. The drawing outline is depicted with

wide lines of 0.7mm thick. The drawing outline

will then be clearly defined and in contrast with

the dimensioning system.

2. The projection lines should not touch thedrawing but a small gap should be left, about 2to 3mm, depending on the size of the drawing.

The projection lines should then continue for

the same distance past the dimension line.

3.Arrowheads should approximately triangular,must be of uniform size and shape and in

every case touch the dimension line to which

they refer. Arrowheads drawn manually should

be filled in. Arrowheads drawn by machine

need not be filled in.

4. Bearing in mind the size of the actualdimensions and the fact that there may be two

numbers together where limits of size are

quoted, then adequate space must be left


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between rows of dimensions and a spacing of

about 12mm is recommended.

5. Center lines must never be used as dimensionlines but be left clear and distinct. They can be

extended, however, when used in the role of

projection lines.

6. Dimensions are quoted in millimeters to theminimum number of significant figures. Forexample, 19 and not 19.0. In case of a decimal

dimension, always use a nought before the

decimal marker, which might not be noticed on

a drawing print that has poor line definition.

We write 0.4 and not .4. It should be stated

here that on metric drawings the decimal

marker is a dot positioned on the base line

between the figures, for example, 5.2 but

never 5 5 with a decimal point midway.

7. To enable dimensions to be read clearly,figures are placed so that they can be read

from the bottom of the drawing, or turning thedrawing in a clockwise direction, so that they

can be read from the right hand side.

8. Leader lines are used to indicate where specificindications apply. The leader line to the hole is

directed towards the center point but

terminates at the circumference in an arrow. A


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leader line for a part number terminates in a

dot within the outline of the component.

In a computer generated drawing most of theseprinciples above can be pre-set accordingly. The mostimportant thing is the clarity of quoted dimensions.

Application of dimensioning principles is best explainin Figure 2.1 below.

FIGURE 2.1 APPLICATION OF DIMENSIONING

PRINCIPLES

The next I will be showing dimension using theprinciples and the one which does not. Let us see thedifferent. Many draftsmen failed to follow theprinciples with so many excuses; like submissionschedules, there is no more time, it was done before,

production department has no complained about thedrawing so why change it now and many otherexcuses just to contradict the established principles.


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Regrettably, this should not be the right attitude ofdraftsmen because drawing is a media in

communicating to workers your intent on how thingsare manufacture. Please view Figure 2.2 intensivelyand compare the difference.

Studying the illustration below; placing dimensionsinside the object is not advisable especially so if it iscrowded. In most cases dimensions crisscross with

each other and cited numbers are unreadable.

FIGURE 2.2DIMENSIONING PRINCIPLESILLUSTRATION

Another typical example draftsmen ignore is theplacement of overall dimensions. The rule is to place

it outside other dimensions, showing the sum of themultiple dimensions. I have seen drawings were it isplace the other way around. See figure 2.3.


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FIGURE 2.3 INCORRECT DIMESIONING PRACTICE

Some of draftsmen and designers assume that by justplacing dimensions anywhere in the drawing is goodenough for as long as it is there and can be

understood. True, but we are no longer living in aworld where we are writing in plant leaves or bark.We have to accept the fact that we aretechnologically oriented professional who shallproduce a better drawing presentation. End user orfabricators expect the best from us.

Check Figure 2.4 below, this is the classical illustration

of what I mentioned earlier. Is this the kind of outputin a computer generated presentation? Maybe we arejust hard headed or ignorant enough that we miss tosee the convenient of other people who will be usingour fabrication drawings.


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FIGURE 2.4 INCORRECT DIMESIONING PRACTICE

I also encountered some dimensions in a fabricationdrawing, although it is correct, can be presented in asimple and much better way as shown in Figure 2.5.The closer the dimensions to the shape (in thisexample is circles) the better.

I do not appreciate any reason why dimension lines

are place all the way to the other side, passing thelength or width of the object, when it can be done onthe nearer side. Embracing the second practice(preferred) bring the fabrication drawing muchclearer.


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FIGURE 2.5 NOT PREFFERED VS. PREFFEREDDIMENSION PRACTICE

Allow me to discuss a little bit about call outs orleader dimensioning. Mistakenly draftsmen ignore thefact that pointing the leader dimension on the shape

being describes (in this case on the elevation, seeFigure 2.6) they set it on the view where the shape isnot properly displayed. This practice to me is notacceptable. I prefer the drawing on the right sidebecause it already shows the outline that is beingdescribed.

FIGURE 2.6 NOT PREFFERED VS. PREFFERED CALL-OUT PRACTICE


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Let us now proceed to the different methods ofdimensioning which are listed below:

1. Chain dimensioning (in Auto-cad it is label ascontinuous dimension).

2. Parallel dimension (baseline in Auto-Cad)3. Running dimension4. Staggered dimension5. Dimensioning circles6. Dimensioning radii7.

Dimensioning spherical radii and diameters8. Dimensioning curves

9. Dimensioning irregular curves10.Angular dimensions11.Unidirectional and aligned dimensions12.Dimensioning tapers13.Dimensioning chambers14.Dimensioning holes15.Dimensioning counter-bores16.Dimensioning squares or flats17.Dimensioning countersunk holes

Before choosing what particular kind of dimensionyou want to use in the preparation of fabricationdrawings. It is wise to coordinate with the production

department and ask them which they prefer to used,anyway they are your client. Nevertheless, if yourcompany have standard drafting manual the betterand just follow their standard. I do not encourage youto change their existing dimensioning method (chain,parallel, running or staggered).

Most of the company now has modern computer

numerical control (CNC) machine. This machinerevolutionized the machining process by just encoding


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data to the computer base on your drawing. The CNCoperator is the most qualified to answer what kind of

dimensioning they are using.

Despite the introduction of the new technology, Ithink it is just fair to explain the characteristic of eachdimension type since at the end, it is the draftsman,designer and fabricator who will be directly benefitedby such clarification. Many designers and draftsman

forgot these dimensions types maybe because theyare already used doing the wrong presentation sinceit is also acceptable in the company and anywayfabricator can also produce windows, doors, curtainwall, etc. without following the principles. However,the fact remains that by following the industrystandard, fabricator will find their task much easier.

1.CHAIN DIMENSIONWhen using chain dimensions take good care of theaccumulation of tolerance as this might endanger thefunction of the part. Many times the overall dimensiondoes not tally with this type of dimension especially ifthe dimension decimal were not set accordingly (autocad drafting). See Figure 2.7 below.

FIGURE 2.7CHAIN DIMENSION


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2.PARALLEL DIMENSONThis kind of dimensioning improved positional

accuracy compare to chain by measuring fromcommon datum, as shown in Figure 2.8. Many CNCoperators prefer this dimensioning.

FIGURE 2.8

PARALLEL DIMENSION

3.RUNNING DIMENSIONThis method is a simplified parallel dimension with theadvantage of less space. See Figure 2.9. In runningdimension it has also common datum similar toparallel dimension. I do not recommend runningdimension to draftsmen and designers in fabrication

drawing.

FIGURE 2.9 RUNNING DIMENSION


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4.STAGGERED DIMENSIONFor staggered dimension see Figure 2.10. For clarity

other dimension were removed.

FIGURE 2.10 STAGGERED DIMENSION

5.DIMENSIONING CIRCLES

It is important to place symbol to indicate thediameter of circle. There are several methods whereindraftsmen can choose which can be determine by thesize of holes. In a computer aided design drafting itautomatically show the type as shown in Figure 2.11.

FIGURE 2.11 DIAMETER OF CIRCLE DIMENSIONAlso accepted is showing the radius of circles in lieudiameter size.


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6.DIMENSIONING RADII

FIGURE 2.12

7.DIMENSIONING SPHERICAL RADII ANDDIAMETERS

In Figure 2.13, the appearance has nothing to do with

orthographic projection which means that views donot have any relationship with each other. This is onlyto illustrate how to dimension spherical radii anddiameters. Notice that dimension lines is drawnpassing thru the arc center or in the case of shortdistances it rest in a line.

FIGURE 2.13


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8.DIMENSIONING CURVESWhere a curve is tangent to a line or lines andmultitude of radii are intersecting which each other asshown on Figure 2.14, it is important to display thecenter line of each curves radii for properdimensioning.

FIGURE 2.13

FIGURE 2.14

9.DIMENSIONING IRREGULAR CURVESIrregular curves maybe dimensioned using ordinates.In Figure 2.15 x and y coordinates were not shownfor clarity the important thing is the intersection ofthese coordinates which determine the point whereeach individual curve starts and where it ends.

Years back, when significant quantities are required

to be produced, fabricator makes a plywood or woodpattern using the coordinates. Today, however due to


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the introduction of computer aided design and CNCmachine this task is easy to work with.

FIGURE 2.15

10.ANGULAR DIMENSIONSAngular dimensions on engineering drawings arestated in degrees, degrees & minutes, and degrees,minutes & seconds. In auto-cad this is just a simpleoperation, by using angular dimension in the pop upmenu then clicking to the angle you want to measurewill automatically produce the actual measurement. Itis up to the designer to fix the default he wantswhether it requires degrees, minutes and seconds ordegrees only.

On Figure 2.16 below, the illustration measure adegrees only as this is the default in the auto-cad.

FIGURE 2.16


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11.UNIDIRECTIONAL AND ALIGNEDDIMENSIONSSimilar to angular as stated previously, aligneddimensions can be easily manipulated in computeraided design drafting. The important thing it ispresented in a very precise and clear manner asshown in Figure 2.17.

FIGURE 2.17

12.DIMENSIONING TAPERSLet me explain first the meaning of taper. Thedifference between dimension X and Y (whetherdiameters or widths) divided by the length betweenthem defines a ratio called taper. See Figure 2.18A.

Formula:Taper = X Y

Length


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FIGURE 2.18A

For example, the conical taper in Figure 2.18B.

Taper = 20 10 = 10 = 0.2540 40

FIGURE 2.18B


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This can be expressed as rate of taper 0.25: 1 indiameter.

An arrow is ISO recommended symbol for taperthis symbol can be added to the drawingaccompanied by the rate of taper (see Figure 2.18b).The arrow indicates the direction of the taper. Whenthe arrow and the rate of taper is enclosed in a boxthis indicates that the taper is required as datum.

For fabrication drawing simplicity however, rate oftaper might not be required for as long as dimensionsX, Y and length are given.

13.DIMENSIONING CHAMFERSDifferent methods of internal and external chamferdimensioning are shown in Figure 2.19.

FIGURE 2.19

14.DIMENSIONING HOLES


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Dimension of the depth of drilled holes, whenspecified in a note form, denotes the cylindrical

portion and not the point left by the drill. If no otherindication is given they are assumed that it gothrough the material. Refer to Figure 2.20C.

FIGURE 2.20

If holes are positioned around pitch circle (PCD) and

may be equally spaced on the main center lines, sizeand location of holes can be dimensioned using call-outs similar to Figure 2.20-A.

When holes are positioned individually, as shown inFigure 2.20-B, PCD dimension, angle dimensions andsize of holes dimension shall be introduced.

15.DIMENSIONING COUNTER BORESIn Figure 2.21-A, B and C alternate methods ofdimensioning counter bores are illustrated which areapplied to elevation and sections..

In all three cases it is important to specify the size of

the needed counter bore. It is not ample to stateCOUNTER BORE FOR M10 RD HD SCREW, since


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obviously the head of the screw will fit into anycounter bore which is larger than the head.

Well, some companys production department mightaccept the above statement for they already knewwhat to do in the fabrication floor. They might haveorganized table for counter bore sizes in every boltsizes.

FIGURE 2.21

16.DIMENSIONING COUNTERSUNK HOLESThe common machined angles for countersunk holesare 60 and 90, to accommodate the heads of thescrew and rivets to provide a flush finish.

It is a good practice to refer to the manufacturerscatalogue for suitable screw and rivets dimensions.

Figure 2.22A, B and C demonstrates the differentmethods of dimensioning countersunk holes (shownin elevation and sections).


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Countersunk holes dimensioning in one of the

company I work simply provides a call out (leaderdimension) by writing(3) COUNTERSUNK HOLES FORM6 X 19mm SCREW. It also worked well because thefabrication department is already aware of what todo.

FIGURE 2.22

17.DIMENSIONING SQUARES OR FLATSIn Figure 2.23A & B, shows a simple dimensioning ofsquare or flats. Nevertheless, standard dimensioningis acceptable.

FIGURE 2.23

Still with me!!! Again let me remind the readers that Iam not imposing the aforementioned principles, since


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there are still many methods in the engineering orISO standard you can implement.

If you feel that the present system you are using nowis sufficient enough for your presentation it is up toyou. Further, if the dimensions, drawings or any ideasexplained in this book will not help in improving thepreparation of fabrication drawings you can just stickwith your old standard, but if you feel the other way

around by all means adopt this now.

3. PROJECT SPECIFICATIONS:

It is imperative that draftsmen, designers and teamleaders shall know by heart the project specificationof each project assigned to them. As a matter of factin every lecture I conducted to the companys newemployeesorientation seminar, I always stressed theimportant of project specifications.

The duty of the design team leader is to read andprepare a summary of project specifications. This stepwill help draftsmen and designers under him in thepreparation not only fabrication drawings but shop

drawings as well. During my time as designsupervisor, this is always the first thing I do sinceevery step in drawing preparation evolve inspecifications. On the part of draftsmen anddesigners, their job is to stick with specifications.

What does project specification has to do in the

production of fabrication drawings? Well, in thefabrication drawings material specification, materialfinishes and profiles are to be indicated.


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I will give some of the available description of the

above, however, to those who are making and usingfabrication drawing I encourage you to continueresearching and reading new reference as newtechnologies in curtain wall industry are introduce dayby day.

Some company describe material as the composition

of profile, sheets and parts. For examples inaluminium this is designated by alloy and temper.

A.Aluminium Plates: AA-3003-H14, AA-5456-H116 and AA-6061-T6

B.Aluminium Sheets: AA-3003-H12, AA-3003-H14, AA-3003-H16, AA-3004-H12, AA-3004-H14 and AA-3005-H34.

C.Aluminium Dies or Profiles: AA-6061-T4, AA-6061-T6, AA-6063-T4, AA-6063-T5, AA-6063-T6, AA-7075-T5 and AA-7075-T6.

For Carbon & Alloy Steel:

A. Great Britain BS 970: 230M07, 070M20,080M40, 070M55, 080A15, 080M13, 709M40,708M40, 817M40, 816M40, 835M30, 655M13,655H13, 722M24, 905M31 and 905M39.

B. U.S.A. AISI/ SAE: 1213, M1020, M1023, 1040,1055, M1015, M1016, 4140, 4142, 4340, 4337,3310, 9314, E71400 and G71406.

There are countries that has their own specification

like; Germany (W-Nr Din), Italy (UNI), Japan (JIS),France (AFNOR) and Spain (UNE). This all depends on


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the project specification and what standard is used.The best reference on this is the structural calculation

made by your companys structural engineers.

For Stainless Steel:

A. Great Britain BS 970:17/4PH, 303S31, 304S11,304S15, 316S31, 316S11, 321S31, 310,416S21, 420S29, 420S37, 420S45, 410S21 and

431S29.B. U.S.A. AISI/ SAE:ASTM A564 Grade 630, 303,304L, 304, 316, 316L, 321, 310, 310S, 416,420, 420F, 410 and 431.

Similar to carbon and alloy steel the best reference onthis is the structural calculation made by yourcompanys structural engineers.

For Glass:

A. Float or AnnealedB. Heat StrengthenC. Fully TemperedD. Heat SoakE. Laminated

The aforementioned glass can be either single glazed,double glazed, insulated glass unit (IGU) and multipleglazed. Different application whether soft coating(sputtered) or hard coating (pyrolytic) can be addedto glass to get the U-Value needed by specification.These can be clear, tinted, coated, reflective and low

emissivity (passive solar Low-E or solar control Low-


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E) application or the combination of either of theabove.

Listed below are other architectural specialty glassesthat can be incorporated in the curtain wall.

A. Low Iron Float GlassB. Transparent MirrorC. Patterned GlassD.

Acid EtchedE.Anti-Reflective Glass

F. Fire-Resistance GlassG. Structural GlassH. Self-Cleaning

Here let me list down the different material finishesfor your guidance.

For Aluminium:

A. MillB.AnodizedC. Powder Coated (preferably for inside finish)D. Super Durable Powder Coated (preferably for

outside finish)E. Polyvinylidene Flouride (PVDF)F.AlodineG. ChromatedH. BrushedI. Mirror

For Steel:

A. Raw


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B. Hot Dipped GalvanizedC. Powder Coated

For Stainless Steel:

A. MillB. SatinC. MirrorD. BrushedE.

MatteF. Bead Blast

4. STANDARD FABRICATION DRAWINGLIBRARY:

The important of standard fabrication drawing libraryespecially in any design organization cannot beoverlooked.

In one company I worked in Saudi Arabia, for the last60 years they continuously update their standarddrawings library. Volumes were completed for aneasy, accurate and speedy future reference in thepreparation of fabrication drawings.

One company in the middle-east, even group theirsystem design components by serial numbering. Like1XXX for mullions, 2XXX for transoms, 3XXX forpressure plates, 4XXX for cover caps, 5XXX forsleeves, 6XXX for gutter splices, 7XXX for glazingadaptor, 8XXX for spandrel glass reducer, etc.

Correspondingly, different system design itself hasown designation. Stick curtain wall uses SW60 for


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60mm width profiles, SW70 for 70mm width profiles,SW80 for 80mm width profiles, SW90 for 90mm width

profiles and so on.Unitized curtain wall system uses similar practice yetinstead of using the prefix SW it uses UCW.

Parts that can be considered as standard are; wallbrackets, shoe brackets, hook brackets, supports,mullion sleeves, transom connectors, corner cleats,

inserts, adaptors, glazing beads, reducers, loadtransfer blocks, gutter splices, toggles, clips, shims,serrated washers and many others.

The parts mentioned earlier can significantly reducethe number of man-hours and mistakes in producingfabrication drawings. It is already in the library andready for printing.

How about standardizing mullions, transoms, andother main curtain wall components? Imagine thesavings!!!

So significant that a fabrication drawings or evenshop drawings, instead of the normal completion of

say three (3) days can be done in one (1) day only.

Not only design department benefits in this issue butproduction/ fabrication department as well. Keepingthese standard parts in the CNC machine or externalstorage will help expedite the production of parts.

R & D Department is usually in-charge in preparing,

filing, modifying and updating the library.Unfortunately, many companies do not see the


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significant of this in connection with fabricationdrawings. True, because the result is not seen in the

early stages in design and drawing process but it willbe cherished in the future. So start now! It is nevertoo late.

5. TODAYS WORLD:

In todays curtain wall industry limitation of materials

is no longer an issue due to the new emergingtechnologies that is being introduces in the market. Inthis regard, fabrication drawing is not only foraluminium mullion, aluminium transoms and glass butas what the architect or consultant desire to do in thebuilding envelope.

It is not even limited to the external curtain wall only

but it is also introduce inside the building.

In order to cover this scope I will try to give exampleof fabrication drawings of aluminium, glass, steel,stainless steel, G.I. sheets and composite cladding.

Let me remind again that different company has their

own way of presenting fabrication drawings. In linewith this, I will present a combination of drawingsfrom different company were I worked before which Ifeel serves my purpose of simplification.

Steps in Fabrication Drawing preparation are asfollows:


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1. Make setting out drawings. These were basedfrom the approved shop drawings which were

submitted to the consultant and returned to us.Included in setting out are tag numbers,assembly dimensions and quantity ofassemblies (can be counted based on tagnumbers). Preferably, it is of great help in thequantification of assemblies if table is providedfor this purpose although it is not mandatory.

2. Produce assembly drawings. Assembly drawingis not only limited to panel but rather itincludes; brackets, supports, handrail, andother relevant curtain wall assemblies.

3. Generate part drawings. As the name impliesthis means individual portion of the assembly.

In curtain wall examples these are; mullion,transom, pressure plate, cover cap, mullionsleeve, wall bracket and shoe bracket (bracketmight be either a sub-assembly or part).

On the next pages, I will be giving fabrication drawingexamples in sequential order following the three (3)

steps in preparing fabrication drawing.

Much my desire to give you as much examples as Ican it is my belief that this guide is not intended forthis purpose. Besides, the basic principles discuss inthis book is sufficient enough in the production ofsimplified fabrication drawings. Therefore, I willpresent few unitized curtain wall system fabrication

drawings.


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In fairness with all the company I work with, I will notmention their names or show their logos in any of the

following drawing examples.6. FABRICATION DRAWING SAMPLES:

FIGURE4

.1-UNITIZEDCURTA

INWALLPARTIALSETTINGOUT


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FIGURE4.2-UNITISEDCURTAINWALLASSEMBLYDRAWING


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FIGU

RE4.3-MALEMULLIO

NPARTDRAWING


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FIGU

RE4.4-FEMALEMULL

IONPARTDRAWING


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FIGURE4.5-SECONDARYTR

ANSOMPARTDRAWI

NG


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FIGURE4.6-INTERMEDIATE

TRANSOMPARTDRA

WING


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FIGU

RE4.7-STACKJOINT

SILLPARTDRAWING


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FIGURE4.8-STACKJOINTGUTTERPARTDRAW

ING


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FIGUR

E4.9-HOOKBRACKETPARTDRAWING


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FIG

URE4.10-SPANDREL

GLASSPARTDRAWING


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FIGURE4.11SAMPLESHEETSH

EARINGCALLOUTS


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When a company have a fabrication and detail

drawing library, fabrication drawings are faster toproduce. Actually, not only fabrication drawings butshop drawings as well. By the way this might onlyapply to common system, not for custom systemdesign. This has been my experience in two of thecompanies in U.A.E. where the fabricators werealready familiar with all the details which guide them

to assemble standard doors and windows.

On windows these may include: punch, striped,casement (side hung), awning (top or bottom hung),sliding and turn/ tilt windows.

While on doors these comprises: hinged, swing,sliding and rotating doors.

Although to some extend this is limited to standarddoors and windows only, this procedure aids in thespeedy production of fabrication drawings.

Further, it is organized to cater all types and systemof standard doors and windows.

Additional examples on the next pages were madeusing the excel format not in auto-cad. It wasprepared in such way that the draftsman or designerjob is to input the quantity, width and height of adoor or window then it will provide result foraccessories, quantities, cutting size of profiles andglass automatically.


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7. REASONS WHY MISTAKES ARECOMMITTED:

I am disappointed to see fabrication drawings go backand forth from the QA/QC department to designdepartment because designers hasten the preparationof drawings. Equally disturbing, is from productiondepartment to QA/QC to design and vice versa. Thissituation is indeed very ironic, nevertheless let us look

deeper into the reasons why these things arehappening. It is ideal if drawings smoothly go throughthese three stages in one direction but realistically itnever happens.

A. SUBMISSION SCHEDULEThe primary reason is schedule commitment. Duringmy stay in United Arab Emirates many companiesanchored their minds on this obligation. For a veryobvious reason; first the company reputation andsecond the company profits.

If a companys reputation is damage they might endup losing more bids in the future. Consequently,

closing the company altogether.

Talking about profits, it is well accepted fact in theconstruction companies that once you miss the targetday, the client can impose penalty to the contractor,maybe every month, every week or worst every daydepending upon the agreement in the construction

contract. Additionally, if a constructions completiongo way beyond the estimated date then companylosses significant amount of money.


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Conversely looking into another philosophy, schedule

commitment (when not properly done, not knowingthe true priorities or not being follow) can even bringmore disaster to both companys reputation andprofits.

How? Let us look at it this way when a submissionschedule is not reasonable; meaning draftsmen and

designers are force to the limit, working overtime andunder pressure. This attitude will lead to moremistakes and subsequently repetition of work, thismean additional overtime is required.

Let me give you an example. Some draftsmen anddesigners will submit incomplete or wrong fabricationdrawings just to meet the schedule date imposed to

them by their supervisors or design manager. Well,documentation wise, this is good because it willappear very nice in the progress report. However, thiswill just add to the delay in the overall submissionbecause it will just come back to them from QA/QCdepartment.

I encountered few draftsmen and designers whosephilosophy is to submit fabrication drawings fast andlet the QA/QC department find the mistakes. This kindof people is not really helping the organization butrather only helping his/her own reputation alone. Thisattitude is passing responsibility to the next link in theproduction chain without remorse.

If a company has internal QA/QC department, all thefull pressure lies on this department. All the mistakes


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and blames are all directed to QA/QC, this is theweakest link, especially if design department will

continue to stick into such philosophy I mentionedabove. Sadly, most of the time this department is theless appreciated in the series of chain. My advice toQA/QC department never comprises company designstandard policy in lieu of schedule. Unless of coursehigher authority overrides such policy, yet under nocircumstances forget to ask a written order

superseding the specific policy.

I came up with my own philosophy with regards toschedule, set aside the schedule primarily just doyour job right the first time and at the endcorrectness of activities will prevail over the schedulethus beating it to become secondary in our activities.

B. EXCESSIVE OVERTIMEThe more overtime being rendered the more problememployee will encounter, both job related activitiesand health. In a study, excessive overtime lead tostress, heart attack, mental fatigue, physical tirednessand other related health illnesses. Researchers in

Britain reported in the European Heart Journal thatpeople who work 10 hours a day is more likely tohave heart related problems than those who workless.

One or two hours overtime made no difference topeoples health, the researchers from University

London and Finnish Institute of Occupational Health

found. But three or more hours led to 60% increasedrisk of coronary heart disease.


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In a circumstance like this, how can an employee

perform his best? Instead of producing one (1)drawing a day he might complete it in two (2) days.This is a fifty 50 percentage decline in his standardoutput. That is a 100 percentage additional draftingcost entail by the company. I do not see the logicbehind this procedure. I rather work in a properlyplan and organize time management environment

than work overtime. This I learned while working inArabian American Oil Company (ARAMCO), Al JubailPetrochemical Company (KEMYA) and Saudi YanbuPetrochemical Company (YANPET) all in Saudi Arabia.

I remember during my time with Aramco, Dhahran inSaudi Arabia, there is a mandatory memorandumfrom the Doctor that employee can only render

overtime to a maximum of 40 hours (if my memory isright) per month. Every manager is directed to abidewith this memorandum, for the same simple reason Ipreviously stated.

Many times, I saw people working excessive overtimeonly to be absent the following day because of

ailment. What happened to the schedule? Lucky, ifbefore the guy got sick he completed his task. Worstcome to worst they even go leaving the company inorder to preserve their physical health and mentalhealth.

Here is an analogy in the petrochemical sector I usedto work before. There are always three lines in the

production of plastic pellets yet these lines are notworking simultaneously in full capacity. During an


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annual preventive maintenance were one line is shutdown, two will run a little bit higher than normal to

compensate for the production loss due to thestoppage of one line.It was never run to produce more in one month (fullcapacity) but rather do it in one in a half or twomonths in a normal speed. This procedure extendsthe life of each line way beyond the designspecifications intend.

Applying this rotational procedure to personnel willnot only preserve the health of the employees buteventually produce similar production result.

Less stress and less pressure is the most conduciveworking environment for it eventually produces morewith lesser mistakes.

C. ORGANIZATION AND COORDINATIONThe third reason is the absence of organization andcoordination between teams. In my own experiencedin a multi-million dollar project in Dubai were 100employees are doing the fabrication drawings is a

testimony that in a situation like this mistakes inpresentation and delayed of submission is an ordinaryincidence.

Seven (7) team leaders were assigned to the project,under them at least fourteen (14) senior designers,designers and draftsmen. Although all the teams workin typical curtain wall cladding they have their own

way of drawing presentation, different bracketlocations, different spread sheet bending dimensions


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deductions and different use of finish in the samematerial parts or assembly to name a few.

Well, this responsibility is for the overall designsupervisor or design manager to see to it that theyare working in a similar design environment.Undesirably, many of these senior staffs do not wantto involve directly in the design process. The result,DISASTER!!

I am also lucky to work in a company were one of thepriority is organization. Our team is composed ofSenior Project Design Manager, Design Supervisor,Material Coordinator, Senior Designer and five (5)draftsmen. We are nine (9) in a team who is doingtwo (2) huge projects simultaneously. One project inKuwait and one project in Paris, France.

How then our team manage to complete the shopdrawings, material take-off (for material purchasing),and fabrication drawings on time? Well, the secret isnot the number of personnel involve but a properorganization and coordination.

I think it will be unfair to you if I will not elaborate

the system that our team particularly used.

1. In the project handover meeting with theConsultant, Contractors, Owner, the SeniorProject Design Manager and Design Supervisorwe the curtain wall contractor readily prepareda set of relevant questions necessary for ourteam advantage.


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2.After preparing the curtain wall system design,our team organized a meeting with the

consultant to present our proposal andsubsequently ask them their comments. This isvery significant because once the consultantsigned the document we minimize the numberof revisions in our drawing. This step leads usto the next.

3.

Our objective is to revised shop drawings (orsystem design) to a maximum of two (2)revision only to get at least status B. Thesoon we get such approval the soon our teamcan order required materials.From here on everything will move smoothly toour benefits. If there is any design changesrequested by the contractor, consultants or the

owner we can even ask additional engineeringcost due to the change. This kind of leverage isworking for the companys gain.

4. On the fabrication drawings, we evolve in aone format presentation. We are lucky that weare very few people in our project

management team. It is easy to coordinateand impose what supervisor wants, besides thecompany has its own standard where the teamconsistently follow regardless of any situationlike schedule of submission.They beauty is, the format is designed where itproduces more assemblies and parts drawingswith less sheet and documentation. In short, it

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month for our team. Well, for most of us this isnot good because less extra money flows into

our pocket, yet remember this... the more youare healthy, the longer you will get moneygoing into your direction.

5. Lastly, we respected each of our insights forthe betterment of the group not for the benefitof the few. Recognition is given to those who

deserve it and not to the manager orsupervisor alone for we know we work as ateam. The success of one is the success of all.This is the greatest secret in any organization.

D. ERRONEOUSCOPY AND PASTE PRACTICESome draftsmen and designers today have the habit

of copying and pasting drawings from previousproject to the present fabrication. This is anadvantage if he/ she will check thoroughly thecorrectness of the copied drawings. Many of themfailed to do so. You and I know precisely theoutcome.

In fabrication copying part drawing from a correctassembly drawing make the activity faster. In thesame manner copying assembly drawing from acorrect setting out drawing will have a similarconsequence.

8. HELPFUL TABLES:

Below you will find tables which can assist in thepreparation of fabrication. ENJOY!!!


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REFERENCES AND FURTHER READING

Colin H. Simmons and Dennis E. Maguire, Manual ofEngineering to British and International Standards,Second Edition 2004.

Brian Griffiths, Engineering Drawing for Manufacture,February 2006.

cw fab guide

Documents