8.2: Working Drawings

8.2 Working Drawings

A working drawing communicates how a project is supposed to be built.

The goal is not to make an impressive drawing.

The goal is to communicate the design clearly enough that a competent woodworker who has never seen the project could understand what to make.

Imagine handing your drawing to:

• another student across the shop;
• an employee in a production facility;
• a cabinetmaker in another state; or
• a manufacturer on the other side of the world.

If that person cannot understand the design without asking you what you meant, the drawing probably needs more information.

Learning Outcomes

After completing this section, you should be able to:

• Explain the purpose of a working drawing.
• Identify common views used to describe a three-dimensional object.
• Explain the importance of dimensions and notes.
• Recognize several common drawing-line conventions.
• Evaluate whether a drawing communicates enough information to build a project.

Drawings in WMT 101

Formal working drawings are not required for every WMT 101 project, but they are strongly recommended as projects become more complex.

The provided project drawings demonstrate how multiple views, dimensions, and details can communicate a design.

Even when you are working from an existing drawing, learning to read it is an important woodworking skill.

Why Draw?

A working drawing allows you to:

• understand the project before cutting material;
• identify the major parts;
• see how parts relate to one another;
• determine important dimensions;
• think through joinery;
• plan the construction sequence;
• identify missing information; and
• communicate your design to someone else.

A drawing is a communication tool.

Three-View Drawings

Many woodworking projects can be described using three basic views:

Front View — Shows the object as viewed from the front.

Top View — Shows the object from above.

Side or End View — Shows the object from one side or end.

Each view communicates two dimensions.

Together, the views help describe the object's:

• height;
• width;
• depth;
• part locations; and
• relationships between components.

Isometric or Perspective Views

An isometric or perspective-style view shows several sides of the project at once.

This can make the overall form easier to understand.

However, a perspective view by itself may not provide enough information to build the project accurately.

Use it to help communicate the form—not as a replacement for necessary dimensions and details.

Dimensions

A working drawing should include the dimensions needed to build the project.

Useful dimensions may include:

• overall height, width, and length;
• material thickness;
• part widths and lengths;
• joint locations;
• groove or dado locations;
• hole locations;
• clearances; and
• important relationships between parts.

Do not add dimensions simply to fill the page.

Include information that helps someone build the project accurately.

Dimension From Useful References

Think carefully about where a dimension begins.

Whenever possible, dimensions should relate to surfaces or features that can actually be established and measured during construction.

Good dimensioning reduces the chance of accumulated errors.

Common Line Types

You may encounter several basic drawing conventions.

Object Line — A solid line showing a visible edge of the object.

Hidden Line — A dashed line showing an edge or feature hidden behind another surface.

Centerline — Identifies the center of a symmetrical feature, hole, or part.

Dimension Line — Shows the distance between two points or features.

You do not need to become a professional drafter in WMT 101, but you should be able to interpret these basic conventions.

Full Size or Scaled

Small objects can sometimes be drawn full size.

Larger projects are often drawn at a reduced scale.

For example:

1 inch on the drawing = 4 inches on the actual project

Whatever scale you use, the written dimensions represent the actual project size.

Do not measure a printed drawing and assume the printout is perfectly to scale unless it is specifically intended for that purpose.

Hand Drawing or Digital Drawing

A useful working drawing can be created with:

• pencil and paper;
• graph paper;
• CAD software;
• 3D modeling software; or
• another method that communicates the necessary information.

The tool is less important than the clarity of the information.

A carefully drawn pencil sketch with good dimensions can be more useful than a sophisticated computer model that leaves out critical construction details.

Drawings Are Not the Construction Sequence

A drawing shows what the project should become.

It does not necessarily show the order in which you should build it.

A finished drawing may show every component at its final dimension, but that does not mean every piece should be cut to final size before assembly begins.

Sometimes it is more accurate to fit later parts to the project as it develops.

The drawing provides the destination.

The plan of procedure provides the route.

Check Yourself

1. What is the primary purpose of a working drawing?
2. What are the three common views in a three-view drawing?
3. Why might an isometric view be useful?
4. What information should dimensions communicate?
5. What is a hidden line?
6. Does a drawing necessarily show the correct order for building the project?
7. What matters more: the drawing method or the clarity of the information?