DVC PLANNERS
PRECISION SHEET METAL LAYOUT MANUAL #1
INTRODUCTION
If you have been working in a sheet metal shop, plan to work in one,
or just want to sharpen and improve your skills with sheet metal then this
manual will help you to do that.
The goal of this manual is to help you gain an understanding of
precision sheet metal layout and show you how to do flat pattern
development while becoming more efficient with math in the shop.
Therefore the first part of this manual deals strictly with math that is related
to sheet metal development. Geometry, Algebra and Trigonometry will all
be used. Don’t let this scare you because once you have something to relate
it to the math becomes easier.
One way of becoming more efficient in math is proper use of the
calculator. The calculator is not always used to its fullest capability in the
shop in most cases. Normally it is used only as an adding machine. I have
even seen people with calculators that are capable of trig functions go and
look up trig tables in a book to complete a problem. People with calculators
also go to fraction charts to convert to decimals when it is just a few key
strokes away on their calculators. The calculator should be used as a
production tool speeding up shop calculations.
This manual was designed to be used with a scientific calculator with
at least trigonometry functions on it. It should also have direct formula
input (Follow mathematical hierarchy rules. see page:2)
http://www.dvcplanners.com
TABLE OF CONTENTS
TOPIC
INTRODUCTION (Scroll UP for intro.) 1
ORDER IN THE MATH 2
ENGLISH DECIMALS 3
GEOMETRY; POINTS, LINES, SEGMENTS, & RAYS 4
PLANES, PLANE AND SOLID GEOMETRY 5
CIRCLES 6
TRIANGLES 7
LOOKING AT TRIGONOMETRY A COMMON SENSE APPROACH 8
SOME COMMON SENSE TRIG FORMULAS 9
RIGHT ANGLE TRIANGLES 10
TRIGONOMETRY MADE SIMPLE 10
WHERE TWO SIDES ARE KNOWN 11
PYTHAGOREAN THEOREM 12
INTERSECTING LINES AND ANGLE RELATIONS 13
SOLVING TRIANGLES 14
PROBLEM SOLVING 15
COORDINATE SYSTEMS 16
NC ANGULAR ORIENTATION 17
BENDING 18
BEND ALLOWANCE 19
BEND DEDUCTION 20
MORE ON BEND DEDUCTION 21
90 DEGREE BENDS 22
90 DEGREE BENDS Cont. 23
DIMENSIONING INTERNAL FEATURES 24
NEUTRAL LINE THEORY 25
NOTCHES 30
RELIEF NOTCHES 31
90 DEGREE V NOTCHES 32
BEND RELIEFS 33
BEND RELIEF SLOTS 34
HEMS 35
JOGGLES AND OFFSETS 36
WORK PROBLEMS 37
SOME COMMON DEVELOPMENT PROBLEMS 39
ACUTE BENDS 40
OBTUSE BENDS 41
OBTUSE AND ACUTE WORK PROBLEMS 42
WORK PROBLEM "SOMEPART" 46
WORK PROBLEM "SAMPLE" 48
DEFINITIONS AND ABBREVIATIONS 50
ANSWER KEY 51
BEND DEDUCTION/BEND ALLOWANCE CHART 55
BACK TO INTRODUCTION
precision sheet metal layout and show you how to do flat pattern
development while becoming more efficient with math in the shop.
Therefore the first part of this manual deals strictly with math that is related
to sheet metal development. Geometry, Algebra and Trigonometry will all
be used. Don’t let this scare you because once you have something to relate
it to the math becomes easier.
One way of becoming more efficient in math is proper use of the
calculator. The calculator is not always used to its fullest capability in the
shop in most cases. Normally it is used only as an adding machine. I have
even seen people with calculators that are capable of trig functions go and
look up trig tables in a book to complete a problem. People with calculators
also go to fraction charts to convert to decimals when it is just a few key
strokes away on their calculators. The calculator should be used as a
production tool speeding up shop calculations.
This manual was designed to be used with a scientific calculator with
at least trigonometry functions on it. It should also have direct formula
input (Follow mathematical hierarchy rules. see page:2)
http://www.dvcplanners.com
TABLE OF CONTENTS
TOPIC
INTRODUCTION (Scroll UP for intro.) 1
ORDER IN THE MATH 2
ENGLISH DECIMALS 3
GEOMETRY; POINTS, LINES, SEGMENTS, & RAYS 4
PLANES, PLANE AND SOLID GEOMETRY 5
CIRCLES 6
TRIANGLES 7
LOOKING AT TRIGONOMETRY A COMMON SENSE APPROACH 8
SOME COMMON SENSE TRIG FORMULAS 9
RIGHT ANGLE TRIANGLES 10
TRIGONOMETRY MADE SIMPLE 10
WHERE TWO SIDES ARE KNOWN 11
PYTHAGOREAN THEOREM 12
INTERSECTING LINES AND ANGLE RELATIONS 13
SOLVING TRIANGLES 14
PROBLEM SOLVING 15
COORDINATE SYSTEMS 16
NC ANGULAR ORIENTATION 17
BENDING 18
BEND ALLOWANCE 19
BEND DEDUCTION 20
MORE ON BEND DEDUCTION 21
90 DEGREE BENDS 22
90 DEGREE BENDS Cont. 23
DIMENSIONING INTERNAL FEATURES 24
NEUTRAL LINE THEORY 25
NOTCHES 30
RELIEF NOTCHES 31
90 DEGREE V NOTCHES 32
BEND RELIEFS 33
BEND RELIEF SLOTS 34
HEMS 35
JOGGLES AND OFFSETS 36
WORK PROBLEMS 37
SOME COMMON DEVELOPMENT PROBLEMS 39
ACUTE BENDS 40
OBTUSE BENDS 41
OBTUSE AND ACUTE WORK PROBLEMS 42
WORK PROBLEM "SOMEPART" 46
WORK PROBLEM "SAMPLE" 48
DEFINITIONS AND ABBREVIATIONS 50
ANSWER KEY 51
BEND DEDUCTION/BEND ALLOWANCE CHART 55
BACK TO INTRODUCTION
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