Workshop Technology Flashcards
What is laying out?
Laying out is the process of scribing or marking centre points of circles, arcs, or straight lines on metals to indicate:
* The shape of the object
* and the position of the holes to be drilled.
What effects does the quality of the layout have on the end product?
The accuracy of the finished products depends greatly on the accuracy of the layout.
From which surface should the layout be made?
Layouts should be made from a baseline or finished surface
To ensure an accurate layout, dimensions, and proper location of holes.
What does the layout drawing not show?
The drawing does not show how much material must be removed from the surface of the casting or workpiece; it merely shows which surfaces are to be finished.
What are the two types of layouts?
The two types of layouts are:
• Basic or semi-precision
• Precision
What is a basic layout?
Semi-precision/basic layouts are not as accurate as precision layouts. It involves the use of basic measuring and layout tools.
What tools are used to make a basic layout?
A ruler or surface gauge can be used to make a basic layout.
What is a precision layout?
Precision layouts are more accurate than semi-precision layouts. It involves the use of more accurate equipment, measuring and layout tools.
What tools are used to make a precision layout?
The vernier height gauge can be used to make a precision layout.
When should precision layouts be used and when should semi-precision layouts be used?
Time should NEVER be spent on making a precise layout if the part does not have to be precise. The layout should be basic/semi-precise if workpiece requirements permit it.
What is a layout solution?
Layout solutions are coated on the surface of metals to make layout lines visible. Layout solutions/dyes are quick drying and produce a background for sharp, clear-cut lines.
What must be done to the surface of the workpiece before a layout solution can be applied?
The surface must be clean and free of grease.
What tools are typically used to apply layout solutions?
They are applied with a cloth, brush or sprayed.
What layout solutions are used for a)steel workpieces and b)casting and hot-rolled steel?
a)For a steel workpiece, copper sulfate is used as a layout solution b)and for casting and hot rolled steel chalk is used.
What are 5 reasons that granite layout tables and plates are considered better than cast iron ones?
Granite layout tables and plates are considered better than cast-iron ones because they:
• Do not become burred
o A burr is a raised edge or small piece of material that remains attached to a workpiece after a modification process.
• Do not rust
• Are not affected by temperature change
• Do not have internal stresses and therefore will not wary or distort
• Are nonmagnetic
• Can be used for checking near grinding machines since abrasive particles will not be embedded in the surface
• Are cheaper than similar-sized cast-iron plate
When using a layout table what are 5 measures that should be taken?
When using a layout table:
• Ensure the working surface is clean
• Cover the plate or table when it’s not in use
• Carefully place the work on the surface plate, NEVER drop a workpiece onto the plate
• Use parallels under the workpiece whenever possible
• Never hammer or punch any layout on a surface plate
• Remove burrs from cast-iron plates and always protect their surfaces with a thin film of oil and a cover whenever they are not in use
What is a scriber and what is it used for?
A scriber has a hardened steel point or points and is used in conjunction with a combination square, rule, or straight edge to draw straight lines.
What is an end bent scriber and what is it used for?
An end bent (angled tip) scriber allows marking lines in hard-to-reach places.
What must be done to ensure that the scriber makes clear layout lines?
The scriber point must always be sharp to make clear layout lines.