March 12th, 2018 - Scale and Design Documentation

posted Mar 13, 2018, 4:22 AM by Mr Becker   [ updated Mar 15, 2018, 4:29 AM ]

Last week we touched on scale drawings. Here are some reinforcing videos on the subject

What is scale.mp4


What Is Scale drawing.mp4

Scaled drawings are a means of communication between the contractor and the designer of a structure, in this case a pulley system. Scaled drawings are used because they allow the designer to put a large amount of information into a relatively small and easily read package.

Be sure you understand the following key terms and add them to your Vocabulary Log in your Engineering Notebook.

Scale: A defined ratio of a model’s size, relative to the actual object that the model represents

Ratio: A comparison between two numbers

Model: Simplified representation of a physical system intended to allow one to more easily analyze and understand the system

Scale Factor: The number by which each dimension of the actual object is multiplied

Design Documentation

In your team, brainstorm Mail Delivery System solutions, including sketches. You should not just copy an entire existing design, but you may take parts of an existing design and make it your own. You must give credit to any design's parts borrowed for your team’s design. Note that the Design Documentation begins today with these initial ideas/sketches, is modified throughout the project, is developed and approved . Your team discusses the pros and cons of each design and narrows down your design ideas to two or three.

Remember to:

• Come to a consensus on two or three designs that might be used for the Mail Delivery System.

• Document these designs, with sketches, in the Engineering Notebook.

• Include a list of simple/compound machines and materials needed for each design.

• Be sure the needed materials are available.

Design requirements identify characteristics necessary to make the solution successful. Effective design requirements fill a need and are feasible (i.e., cost effective and efficient, user friendly, environmentally friendly, safe). The design has to be able to change based on further research and experience as well. As part of the Engineering Design Process, design documentation is required. Design documentation is an organized collection of documents that capture design decisions and solutions. Documentation is a crucial component of successful product planning and implementation, so it is important that it communicates as effectively as possible.


Elements of successful design documentation include, but are not limited to, scope of work definition and design development. Each document must have identification such as project title, original date of

document and names of students on the team, name of the person approving the original document, dates of revisions and name of person approving the revision, and a brief explanation of the revision. Each design might include conceptual drawings, assembly drawings, a parts list, parts drawings, process drawings, flowcharts, state diagrams, use cases, relational tables, tables, programs developed, charts, graphs, rules, symbol diagrams, decision matrix ladder diagrams, Computerized Numerical Control (CNC) programs, schematics, and other items.

Your team researches the viability of your brainstormed designs and comes to a consensus on the best two or three designs. Think about:

• What simple and compound machines are used in your design?

• Do you have all of these materials?

• What are the constraints of this project?

Communication to the team during the conceptual and design phase is critical. Teams must schedule meetings to discuss the design throughout the planning phase. Discussions should include topics such as safety considerations, location, size, and other key issues. Documentation of these discussions must be reported. The design must be approved before building of the prototype can begin.

A copy of the Design Brief Template and Decision Matrix are attached at the bottom of this page.  Please use these to walk through your design brief and include on your portfolio site for this project.

Mail Delivery System Model Limitations


The scale model maximum size can be no larger than:

·         5 feet long

·         5 feet wide

·         41-45 inches high from the road surface

The scale model does not have to be the maximum sizes but must use correct proportions.

The teacher/school is the main source of materials used to build the scale model.

Students may not purchase extra materials or ask parents to purchase materials.

Students may bring “junk” from home with prior approval.

The scale model must function exactly like the full size Mail Delivery System.

The full size Mail Delivery System has a distance of 20 ft. from the street side mailbox to the house, the mailbox has a height of 5 ft., and the mail weighs 8 oz.

Mr Becker,
Mar 15, 2018, 4:34 AM
Mr Becker,
Mar 13, 2018, 4:22 AM
Mr Becker,
Mar 13, 2018, 4:22 AM