Chapter 7 – Layout Work MMC 117 Tools, Machines &
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Chapter 7 Layout Work MMC 117 Tools, Machines Fabrication TAE 550 Metal Fabrication Modern Metalworking Learning Objectives Explain the purpose of a layout and how it is used to prepare metal for machining. Identify common layout tools
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Chapter 7 – Layout Work MMC 117 Tools, Machines & Fabrication
TAE 550 Metal Fabrication
Modern Metalworking<br>
TAE 550 Metal Fabrication
Modern Metalworking<br>
02
Learning Objectives Explain the purpose of a layout and how it is used to prepare metal for machining.
Identify common layout tools and use them safely.
Identify angular measurement tools and use them safely Goodheart-Willcox Publisher<br>
Identify common layout tools and use them safely.
Identify angular measurement tools and use them safely Goodheart-Willcox Publisher<br>
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Learning Objectives Perform the necessary calculations to set up a sine bar and sine plate.
Make simple layouts using layout tools.
List and observe common safety precautions used in layout work. Fowler Company, Inc.<br>
Make simple layouts using layout tools.
List and observe common safety precautions used in layout work. Fowler Company, Inc.<br>
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Preparing Metal for Layout
Layout Tools
Measuring Angles
Other Layout Tools and Equipment
Making a Layout
Safety Precautions for Layout Work Topics 4 MMC 117 v1 Tools, Machines, & Fabrication<br>
Layout Tools
Measuring Angles
Other Layout Tools and Equipment
Making a Layout
Safety Precautions for Layout Work Topics 4 MMC 117 v1 Tools, Machines, & Fabrication<br>
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Layout Work Layout
Locating and marking lines and reference points
Marks indicate shape & size of a part or its features and are used as a guide for machining while checking work by measurement. Goodheart-Willcox Publisher<br>
Locating and marking lines and reference points
Marks indicate shape & size of a part or its features and are used as a guide for machining while checking work by measurement. Goodheart-Willcox Publisher<br>
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One of your first jobs after obtaining material from stock will be to measure and lay out where the material will be cut.
May be a simple pencil or chalk mark
Is one of the basic tasks of semi-precision layout.
In this class, you will be concerned with layout for stock cutoff, filing and off-hand grinding, and drilling.
The process of layout can generally be classified as semi precision and precision.
Semi-precision layout - rule measurement to a tolerance of+/-1/64 in.
Precision layout done with tools that discriminate to .001 in. or finer, to a tolerance of +/-.001 in. if possible. Layout Work 6 MMC 117 v1 Tools, Machines, & Fabrication<br>
May be a simple pencil or chalk mark
Is one of the basic tasks of semi-precision layout.
In this class, you will be concerned with layout for stock cutoff, filing and off-hand grinding, and drilling.
The process of layout can generally be classified as semi precision and precision.
Semi-precision layout - rule measurement to a tolerance of+/-1/64 in.
Precision layout done with tools that discriminate to .001 in. or finer, to a tolerance of +/-.001 in. if possible. Layout Work 6 MMC 117 v1 Tools, Machines, & Fabrication<br>
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Layout dye in several colors is available.
Red, blue, and white.
The blue dyes are common.
Apply sparingly and evenly in an even coat.
Place a paper towel under the workpiece to prevent layout dye from spilling on the layout table.
Avoid breathing the vapors. 7.1 Preparing Metal for Layout 7 MMC 117 v1 Tools, Machines, & Fabrication<br>
Red, blue, and white.
The blue dyes are common.
Apply sparingly and evenly in an even coat.
Place a paper towel under the workpiece to prevent layout dye from spilling on the layout table.
Avoid breathing the vapors. 7.1 Preparing Metal for Layout 7 MMC 117 v1 Tools, Machines, & Fabrication<br>
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Layout Tools Draw layout lines, arcs, and points on metal Scriber
Divider
Trammel
Hermaphrodite caliper
Surface gage
Centerhead
Squares
Combination set<br>
Divider
Trammel
Hermaphrodite caliper
Surface gage
Centerhead
Squares
Combination set<br>
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The pocket scriber has a removable tip, stored in the handle, to permit it to be safely kept in a pocket.
The engineer’s scriber has hooked end, which permits easier access to the line to be scribed.
The machinist’s scriber has only one end with a fixed point. 7.2 Scriber 9 MMC 117 v1 Tools, Machines, & Fabrication<br>
The engineer’s scriber has hooked end, which permits easier access to the line to be scribed.
The machinist’s scriber has only one end with a fixed point. 7.2 Scriber 9 MMC 117 v1 Tools, Machines, & Fabrication<br>
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Dull scribers must be reground or stoned to restore their sharpness.
Tips should be sharpened to a triangular shape rather than a conical point.
This keeps it sharper longer & scribes cleaner lines.
Tilt the scriber so the tip marks as close to the rule as possible to ensure accuracy. 7.2 Layout Tools - Scribers 10 MMC 117 v1 Tools, Machines, & Fabrication<br>
Tips should be sharpened to a triangular shape rather than a conical point.
This keeps it sharper longer & scribes cleaner lines.
Tilt the scriber so the tip marks as close to the rule as possible to ensure accuracy. 7.2 Layout Tools - Scribers 10 MMC 117 v1 Tools, Machines, & Fabrication<br>
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Spring dividers range in size from 2 - 12 in.
Spacing of the legs is set by turning the adjusting screw.
Dividers are usually set to rules.
Engraved rules are best, as the divider tips can be set in the engraved rule graduations. 7.2 Layout Tools - Dividers 11 MMC 117 v1 Tools, Machines, & Fabrication Divider tips must be kept sharp and at nearly the same length.
Spring dividers are used to divide lines & circumference of circles.<br>
Spacing of the legs is set by turning the adjusting screw.
Dividers are usually set to rules.
Engraved rules are best, as the divider tips can be set in the engraved rule graduations. 7.2 Layout Tools - Dividers 11 MMC 117 v1 Tools, Machines, & Fabrication Divider tips must be kept sharp and at nearly the same length.
Spring dividers are used to divide lines & circumference of circles.<br>
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Trammel points are used for scribing circles & arcs when the distance exceeds capacity of the divider.
Trammel points are either attached to a bar & set to circle dimensions or clamped directly to a rule and set directly by rule graduations. 7.2 Layout Tools - Trammel 12 MMC 117 v1 Tools, Machines, & Fabrication<br>
Trammel points are either attached to a bar & set to circle dimensions or clamped directly to a rule and set directly by rule graduations. 7.2 Layout Tools - Trammel 12 MMC 117 v1 Tools, Machines, & Fabrication<br>
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The hermaphrodite caliper has one leg similar to that of a regular divider & a tip adjustable for length.
The other leg has a hooked end that can be placed against the workpiece edge 7.2 Layout Tools – Hermaphrodite Caliper 13 MMC 117 v1 Tools, Machines, & Fabrication<br>
The other leg has a hooked end that can be placed against the workpiece edge 7.2 Layout Tools – Hermaphrodite Caliper 13 MMC 117 v1 Tools, Machines, & Fabrication<br>
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Safety Notes
Never carry an open scriber, divider, trammel or hermaphrodite caliper in your pocket.
If your pocket scriber has a removeable point, reverse it when the tool is not in use.
Always cover all sharp tool points with a cork when not in use.
When laying out work, place tools on the bench with the points facing away from you.
Avoid handling a sharp tool to another person with the pointed end sticking out.
Wear goggles when grinding the points of a scriber. 7.2 Layout Tools – Safety 14 MMC 117 v1 Tools, Machines, & Fabrication<br>
Never carry an open scriber, divider, trammel or hermaphrodite caliper in your pocket.
If your pocket scriber has a removeable point, reverse it when the tool is not in use.
Always cover all sharp tool points with a cork when not in use.
When laying out work, place tools on the bench with the points facing away from you.
Avoid handling a sharp tool to another person with the pointed end sticking out.
Wear goggles when grinding the points of a scriber. 7.2 Layout Tools – Safety 14 MMC 117 v1 Tools, Machines, & Fabrication<br>
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The surface gage consists of a base, rocker, spindle adjusting screw & scriber.
The spindle pivots on the base & can be moved with the adjusting screw.
The scriber can be moved along the spindle & locked at any desired position.
A surface gage may be used as a height transfer tool. 7.2 Layout Tools 15 MMC 117 v1 Tools, Machines, & Fabrication<br>
The spindle pivots on the base & can be moved with the adjusting screw.
The scriber can be moved along the spindle & locked at any desired position.
A surface gage may be used as a height transfer tool. 7.2 Layout Tools 15 MMC 117 v1 Tools, Machines, & Fabrication<br>
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The centerhead is part of the machinist’s combination set.
When the centerhead is clamped to the combination set rule, the edge of the rule is in line with a circle center. 7.2 Layout Tools - Centerhead 16 MMC 117 v1 Tools, Machines, & Fabrication Using the centerhead to lay out a centerline on round stock.<br>
When the centerhead is clamped to the combination set rule, the edge of the rule is in line with a circle center. 7.2 Layout Tools - Centerhead 16 MMC 117 v1 Tools, Machines, & Fabrication Using the centerhead to lay out a centerline on round stock.<br>
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7.3 Measuring Angles 17 MMC 117 v1 Tools, Machines, & Fabrication Scribing an angle line using a centerhead.<br>
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Squares Squares are used to check the accuracy of 90° angles.
Hardened steel square L. S. Starrett Co. Extreme accuracy
True square or right angles on inside and outside<br>
Hardened steel square L. S. Starrett Co. Extreme accuracy
True square or right angles on inside and outside<br>
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Squares Double square
Blade is adjustable and interchangeable
Standard graduated blade, beveled blade, drill grinding blade L. S. Starrett Co.<br>
Blade is adjustable and interchangeable
Standard graduated blade, beveled blade, drill grinding blade L. S. Starrett Co.<br>
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Combination Set Hardened blade, square head, center head, spirit level, and bevel protractor Goodheart-Willcox Publisher<br>
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Combination Set Square head used as standard square and miter square
Center head locates center of round stock
Protractor head rotates through 180° Goodheart-Willcox Publisher<br>
Center head locates center of round stock
Protractor head rotates through 180° Goodheart-Willcox Publisher<br>
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Layout hammers are usually lightweight 2 - 4 oz machinist’s ball-peen hammers
A heavy hammer should not be used in layout, as it tends to create unnecessarily large punch marks.
The toolmaker’s hammer is equipped with a magnifier that can be used to help locate a layout punch on a scribe mark 7.4 Other Layout Tools and Equipment 22 MMC 117 v1 Tools, Machines, & Fabrication<br>
A heavy hammer should not be used in layout, as it tends to create unnecessarily large punch marks.
The toolmaker’s hammer is equipped with a magnifier that can be used to help locate a layout punch on a scribe mark 7.4 Other Layout Tools and Equipment 22 MMC 117 v1 Tools, Machines, & Fabrication<br>
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Difference between a layout punch and a center punch.
The layout, or prick punch, shown here, has an included point angle of 30 degrees.
The slim point facilitates the locating of the punch on a scribe line & it is the only punch that should be used in layout.
A prick punch mark is used to preserve the location of a layout mark & does minimum damage to the workpiece. 7.4 Other Layout Tools and Equipment 23 MMC 117 v1 Tools, Machines, & Fabrication<br>
The layout, or prick punch, shown here, has an included point angle of 30 degrees.
The slim point facilitates the locating of the punch on a scribe line & it is the only punch that should be used in layout.
A prick punch mark is used to preserve the location of a layout mark & does minimum damage to the workpiece. 7.4 Other Layout Tools and Equipment 23 MMC 117 v1 Tools, Machines, & Fabrication<br>
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The center punch, shown here, has an included point angle of 90 degrees & is used to mark the workpiece prior to such machining operations as drilling.
The center punch is used only to deepen the prick punch mark.
On some workpieces layout punch marks are not acceptable, as they create defects in the material.
Before using a layout punch, you must make sure it is acceptable, as a punch mark may affect surface finish or metallurgical properties.
In all cases, layout punch marks should be of minimum depth. 7.4 Other Layout Tools and Equipment 24 MMC 117 v1 Tools, Machines, & Fabrication<br>
The center punch is used only to deepen the prick punch mark.
On some workpieces layout punch marks are not acceptable, as they create defects in the material.
Before using a layout punch, you must make sure it is acceptable, as a punch mark may affect surface finish or metallurgical properties.
In all cases, layout punch marks should be of minimum depth. 7.4 Other Layout Tools and Equipment 24 MMC 117 v1 Tools, Machines, & Fabrication<br>
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You may use several types of height gages for layout applications
The height gage scriber is attached to the vernier slide and can be moved up and down the beam.
Scribers are either straight or offset. 7.4 Other Layout Tools and Equipment 25 MMC 117 v1 Tools, Machines, & Fabrication<br>
The height gage scriber is attached to the vernier slide and can be moved up and down the beam.
Scribers are either straight or offset. 7.4 Other Layout Tools and Equipment 25 MMC 117 v1 Tools, Machines, & Fabrication<br>
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A surface plate provides an accurate reference plane for layout & inspection measurements.
A large-area 4 x 8 ft layout table may be used.
Any surface plate/layout table is a precision tool.
Covered when not in use; kept clean when being used.
No surface plate should be hammered on, as this will impair the accuracy of the reference surface. 7.4 Surface Plates 26 MMC 117 v1 Tools, Machines, & Fabrication Cast iron & semisteel surface plates are made from good- quality castings that have been allowed to age, thus relieving internal stresses. Granite is superior to metal because it is harder, denser, impervious to water, and if chipped, the surrounding flat surface is not affected.<br>
A large-area 4 x 8 ft layout table may be used.
Any surface plate/layout table is a precision tool.
Covered when not in use; kept clean when being used.
No surface plate should be hammered on, as this will impair the accuracy of the reference surface. 7.4 Surface Plates 26 MMC 117 v1 Tools, Machines, & Fabrication Cast iron & semisteel surface plates are made from good- quality castings that have been allowed to age, thus relieving internal stresses. Granite is superior to metal because it is harder, denser, impervious to water, and if chipped, the surrounding flat surface is not affected.<br>
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Scribing a Layout Study drawing and plan layout sequence PROCEDURE Goodheart-Willcox Publisher<br>
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Scribing a Layout PROCEDURE Goodheart-Willcox Publisher<br>
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Scribing a Layout Cut stock
Clean work surface
Locate and scribe layout reference lines or base lines
Locate center points of circles and arcs PROCEDURE<br>
Clean work surface
Locate and scribe layout reference lines or base lines
Locate center points of circles and arcs PROCEDURE<br>