EngineeringDesign I

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Table of Contents

Design Constraints• Constraints• Design constraints

– Functionality– Machine-able– Feasibility – Time– Size– Weight– Maintainability

• Big picture

Design Process• Brainstorming• Narrowing the design• Prototyping• Redesigning• Finalizing the design• Inventorizing• Machining• Building/Assembly

Design Constraints

Constraints

As an engineering there are many constraints to worry about

Design Constraints

• Functionality• Machine-able• Feasibility • Affordable – Time, man power, cost• Size and Weight• Maintainability• Cost Effective• Replaceable• Programmable• Practical

Functionality

• What are you trying to accomplish? • Functionality - The function you want the

part to serve– Maximize how well the part works– Simple is always better

Machine-ability

• How easy it is to machine the part– We have limited resources and machine most

of the parts ourselves

• Timing and feasibility are key– Timing – limited time can be spent machining– Feasibility – Our machines can only do so much

Cost

• We have a limited amount of funds allotted from our budget to spend on the robot

• You are only allowed to spend a fixed amount on the final robot

• Specialty parts and shipping costs add up

Size

• The robot can only be 28” x 38” x 60”• Need to fit…

– Electrical components– Different manipulators

• Ex. Minibot release and arm

Weight

• The robot has a maximum weight– Ex. maximum 120 lbs.

• Includes arm, minibot release, electronics• Does not include the battery or bumpers

Maintainability

• After building, you need to maintain all the parts– Ex. If you have surgical tubing, it needs to be

changed often– Ex. Tightening bolts, wires

Big Picture

• Needs to fit constraints present by FIRST– Ex. Size and weight

• Follows the spirit of FIRST• Able to be integrated with the design of

the rest of the robot• KISS – Keep It Simple Stupid

Design Process

Design Process

Brainstorming

• Understand the challenge • Come up with ideas• Evaluate the ideas by considering the

constraints and using Common Knowledge

Narrowing the Design

• figure out details of the design on paper and later inventor– More details on paper = easier to put into

inventor

• Come up with plan for prototype• Figure out how parts connect together• Choose materials and other specifics of

the design • Re-evaluate design with considering the

other components of the robot

Prototyping

• Build a prototype of the design• Use cardboard and other easy to find

material• Purpose: Proof of concept

– Starts addressing issues that will come up in the real part

Design Review

• Get advice from experts in the field– Ex. mentors

• Welcome constructive criticism– Helps solve design flaws– Introduces new ideas

• 1-2 every build season

Redesign

• Use feedback from Design Review• Enhance design

– Fix flaws by either fixing the prototype or creating a new prototype

• Come up with a better big picture of the design

Finalizing the Design

• Finalize the design• Figure out how the different components will

connect• Finalize the material

– Ex. bosch vs. Aluminum

• Connect with the rest of the robot– Make sure you are doing this throughout the whole

process because many of your constraints are due to other components of the robot

• Address all the constraints – cost effect, weight, and functionality

Inventor

• Put the final design on Inventor– Should be creating inventor drawings

throughout but want to make sure to have a final drawing

• Purpose: Helps with putting together the design of the entire robot – Helps address problems in specific part of the

component of the robot– Helps with Machining– Another Visual of Robot

Machining

• Designs are sent to woodshop to be made• Remember, setting up for the process is

hardest– Don’t make the machinist re-make a part later

because you created the part wrong the first time

• Accuracy is the most important thing to remember– Think about what the part is using and how if this

one part is messed up how it will affect everything else

Building/Assembly

• Putting all the parts together• Make sure the parts are secure

– See where parts are weak that you didn’t expect

• Maintenance is important here:– Screws and Bolts do come loose as the robot

moves