Choosing Your Next Mechanical Design Project

There’s no doubt that designing a gesture-controlled robot from scratch will put your mechanical engineering skills to the test.


But let’s be honest.


If you’re just getting started with mechanical engineering, a custom robot may not be in the cards just yet. 


That’s because the engineering process is iterative


You’ll rely on incremental learning from your past experiences and others to solve the most challenging problems.


You’ll always want to build upon your current skills and hone your craft as an engineer. But you also want to limit the feelings of frustration, as they can make you want to give up altogether.


Remember:


Learning and developing experience in mechanical design is a journey, not an event. They said that progress equals success, and this has never been truer than when embarking on a mechanical design project.


So, do you need a little help in choosing your next project? 


We’ll show you how. 


It starts with a basic understanding of the mechanical design process:

Determine a Problem Statement

Nearly every design in the universe came from a need or a “problem.” Some designs result from low funding or a desire to enhance efficiency, while others are all about convenience.


That brings us to the first step of the mechanical engineering design process.


Instead of asking yourself, “What do I want to make?” ask, “What problem needs fixing?”


Why the Problem Matters

Let’s look at the example of the modern-day braking system.


In the 1800s, a cross-town venture meant hopping into a wooden-wheeled Benz Motorwagen and traveling down dusty dirt roads. A lever-activated wooden block brake could grind the spokes to a halt in a matter of seconds.


Imagine doing that in a Mazda Miata at 80 mph.


As the automotive industry shifted toward rubber wheels, 30 mph vehicles, and long-distance travels (a la Ford’s historic Motor T), those old-school wooden brakes were useless. This need to adapt for safety, speed, and road conditions triggered the later mechanical drum brakes.


Next came shoe brakes because drivers grew tired of pulling a lever to slow down. And then hydraulic brakes made their big debut. Today, high-tech vehicle developments have led to an anti-lock braking system (ABS) designed to be safer and more efficient than ever.


In other words:


Without a need to fine-tune brakes over the centuries, the idea behind ABS would’ve never come to fruition.

Examples (To Get the Creative Juices Flowing)

Tinkering around with CAD models in SolidWorks can help you to master the program’s skills — a definite resume booster when it comes time to apply post-graduation! 


But without a problem requiring a solution, how much experience can you really gain from an engineering perspective?


Our tip: Examine your own life and figure out which tasks you can make easier, more affordable, or more efficient. Think about how you can use automation to take the manual labor out of certain tasks, too.


For example:


  • How to slash your electricity bill

  • How to automate menial tasks like taking the trash out

  • How to build gadgets at home on a strict budget

  • How to do the dishes without getting out of bed

  • How make wheelchair navigation simpler on ramps and in homes

It helps to document the problem while you’re still in the “before” stage. 


For example, if you're looking to slash your monthly electric bill, jot down the cost of your average bill beforehand. That way, you'll be able to say you cut your bill by a particular percentage (20%) with your power generation solution.


RocketGear strives to offer courses that give you direct skills to apply to practical problems, such as our interactive Introduction to Mechanical Engineering with Solidworks course.

Detail Customer (or Project) Requirements

Now that you’ve determined which problem you’re looking to solve, it’s essential to take a step back and look at the entire picture. 


As an engineer, you’ll face constraints. 


Clients may set a $200 cost-per-unit budget for an ergonomic gas canister design with a specific function in mind. Or, you might not have a 3D printer on-hand, leaving you to order parts from pricey online services that take forever to ship. 


Or, not having a CNC machine altogether.


There are three key things to gather when detailing customer (or, in this case, project) requirements: 


  1. Objectives

  2. Functions

  3. Constraints


Here’s what each of these terms means (and why it matters):

Objectives

Objectives are often misunderstood in the mechanical design process.


So, whether you’re developing a prototype to tackle a problem of your own or working directly with a paying client, the objectives should be a compilation of adjectives that can be measurable.


Think in terms of what the design is rather than what the design does


In other words, objectives are quantifiable desired attributes that you can validate design ideas against.


We’ll cover how to accomplish the objectives in a bit. 


For example, say you have a problem reaching top shelves in the kitchen or changing light bulbs. And the current solution of getting the clunky, heavy step stool just isn't cutting it for you...

The WRONG Way to State Your Design Objectives:


An objective reading, "A 1 ft. stool for stepping on to reach objects on a shelf", is not an objective but rather a solution and containssolution bias. Solution bias is when you, as the engineer, try to include the how with the what. 


As people, we often associate new solutions to things we already know. 


We know that step-ladders are great for getting things off the top-shelf, and so our minds intuitively fixate on that as the objective. 


It's also not measurable. 


So, when comparing different design ideas, you wouldn't be able to determine how effective one is over the other. (i.e., Solar vs. geothermal).


Your design objectives are the concrete criteria that you will utilize to choose between different conceptual designs and ultimately to determine if the final design is a success or not.

The RIGHT Way to State Your Design Objectives:


Better objectives in the scenario above would be:


  1. Low cost

  2. Small

  3. Portable

  4. Lightweight (no more than 3 lbs)

  5. Extensible/adjustable for people of different heights


These objectives give you direct insight into what success means to solve this problem without constricting the design space


The design space is simply the possibility of design alternatives that contain all of the potential solutions to our design problem. 


A large design space means there are many acceptable solutions to the problem, while a small design space means there are few proper solutions (e.g., high-precision medical devices). 


It's crucial at the objective stage not to introduce solution biases that constrict the design space so early on in the process, as that limits innovation and imagination. 


While it is appropriate to note constraints such as weight limits, size limits, and cost limits, details focused on a particular type of solution are best if avoided.


Your objectives should be measurable, ranked in preference, and define success for solving this problem. 


Not how to achieve that success.

Functions

You considered the design's attributes, what measurable qualities it needs, and ultimately defined success in the previous step. 


Sometimes, the design has to do something. 


In other words, it takes some input of human interaction and produces some output (also known as "function"). There are two types of functions: Enabling and restrictions (although not standard industry terms).


An enabling function enables user input to achieve something, like squeezing a trigger to fold a step-stool for greater portability. And a restricting function resists user input to withstand something, like resisting the force of gravity of a user standing on a step-stool and not falling. 


It would be a pretty useless step-stool if, after the second time you climbed it, it collapsed because the resisting of gravity wasn’t a required function. 


“It was a nice-to-have feature when planning wouldn’t cut it!”


At this point, you don't have to worry about figuring out how to achieve these functions but rather identify them. And if possible, define detailed requirements (e.g., specifications around them like a maximum weight limit).

Constraints

Before you move onto the initial design phase, you need to look at what you have and what you need. We're talking about constraints, and these can either make or break your next big design.

Tools


Take inventory of what you have in your physical and technological toolkits. 


  • Do you have access to CAD software like SolidWorks to bring your design to life via a 3D model, saving you hours in the prototyping stage? 

  • How about a physical toolkit with a lathe, screwdriver, and drill? 

Complexity


The only way to improve your mechanical design skills is by practicing and taking on more in-depth and major projects. Yet, you want to ensure the chosen design is both manageable and within your capabilities.


For example, a SolidWorks model of a suspension bike is somewhat reasonable for beginners. Meanwhile, converting your vision into a physical, fully-functioning prototype might be more of a final year capstone project as a mechanical engineering student.

Time (and Money)


Is mechanical design a hobby you practice in your free time after class? Or are you juggling a full-time mechanical engineering course load while getting a few portfolio-bolstering mechanical engineering projects under your belt?


Look at your time, then compare it to your budget.


Ensure that you’ll make a profit on the project and that, if it’s merely a hobby, it doesn’t consume more than 10% of your time. When mechanical design begins to hurt your bank account or consume what seems like your entire life, you’ll reach the dreaded point of no return: “Maybe I can’t handle this.”


Develop Conceptual Designs

By this point in the process, you’ve successfully established the framework for your next mechanical design project. You have a good idea of what it should be and what it should do.


Now, it’s time to bring your visions to the drawing board and kick off the brainstorming process.


The first step: Determining the design space.


That is, tinkering with your vision to create one (or more) design alternatives that’ll help “solve” the problem you determined in step one via:

Morphological Chart

A morph chart helps to breakdown the key features or functions of the system design (left column) while also factoring in your design alternatives (top row).


In the intersecting boxes, you’ll come up with possible “solutions,” like adding thick layers of sheet metal to a robot to create an indestructible exterior.


This is where many newbie students can struggle. 


If you don't have a lot of experience in mechanical engineering, you ask the $1,000,000 question, "What are the possible solutions, and how do I find them?" 


As you get more experience and grow in your skills, this will come more naturally. But even in the professional world, engineers may have a tough time approaching solutions for given problems because they're complicated.


Here are some tools that can help you ideate:


  1. Analogies

  2. Research - Literature Reviews and patents for bleeding-edge methods

  3. Research mainstream methods - reverse engineering and benchmarking


Let’s review what each of these means:

Analogies


Analogies trigger inspiration at times when you might not be actively brainstorming for solutions. There are three critical types of analogies in engineering design:


  • Direct analogies: For example, creating a velcro-like material after witnessing prickly plant burrs “lock” onto fabrics

  • Symbolic analogies: A stream of thoughts leading to an eventual discovery based on previous mental comparisons

  • Fantasy analogies: Ideas with bizarre, mythical, or outlandish explanations that might just work in the current scenario

In other words, analogies are metaphors. 


You’re merely comparing what you want your design to do (or look like) to things that already do so — or at least do something similar. 


A good example of this is in Computer Science/Software Engineering. 


Machine learning has taken the world by storm via Deep Learning, which uses neural networks. Neural networks are based and inspired by the human brain and how our brains boast billions of neurons connected ever-so-intricately. This is where the art of engineering comes in and is somewhat a creative process of observing and brainstorming.


This method is typically helpful when you have mechanical engineering context and can relate things you see and observe to particular mechanical engineering solutions (in ways that you may not have thought of before).


If the problem is really complex, you may want to start with doing more research with bleeding-edge methods through literature reviews or patent searches. For someone with less experience, the simplest way to get started quickly is understanding how to accomplish similar functions by just taking apart a similar product.

Conducting Literature Reviews and Patent Searches


When you feel "boxed in," or like your current design space has far too many constraints, branch outward. Read up on the latest handbooks, academic journals, research papers, or patents to gain some inspiration and explore more out-of-the-box ideas. 


Benchmarking and Reverse Engineering


There are many ways to solve problems. But current methods are the best starting point, where you can optimize a drawback with an existing solution. 


This is a great starting point for someone with less experience, as you can:


  • Start with a working solution

  • Understand how the solution operates

  • Identify opportunities for improvement


Building on top of benchmarking, you can reverse-engineer similar products to examine the inner mechanisms. Thanks to this old-school method, you can learn how these designs work and determine how to transfer your envisioned design's specific functions.


Once you've determined solutions for the morph chart, you can start visualizing them.

Sketches

Most concept designs include some sketches and reference images of similar designs.


So, use a pencil and paper to draw a general outline of how this design will look once complete. It helps to note dimensions, list necessary materials, and add color when possible.

Fine-Tune a Preliminary Design

The complete brainstorming process can easily take hours, days, or even weeks. But you’ll eventually narrow down your dozens of sketches and prototypes into a handful of practical project ideas.


In the preliminary design phase, you’ll have to decide which designs best accomplish both the functions and objectives that you identified earlier and compare them against the metrics you established for the objectives to determine the “best” one. 


If you haven’t established metrics yet, now is the time to do so.


Some examples of evaluation criteria, aka metrics, include:


  • Flexibility

  • Reliability

  • Cost

  • Durability

  • Productivity

  • Color

  • Form and shape

  • Maintenance requirements

  • Customer requirements

  • Fuel or power usage

Of course, there are always trade-offs when coming up with a final, preliminary design. 


Above all else, you need to compare your designs to the metrics established and figure out which is the “best one.” Sometimes, weeding out the duds requires building a prototype (or a virtual model via CAD/CAE tools). 


Choosing a design because you like the color (an easily changeable characteristic) while shelving the other five metrics you set wouldn’t make sense.

Craft a More Detailed Design

By now, your design has been confined to your own cranium and loose sheets of draft paper. You’re ready to enter the second-to-last stage of the process:


Converting your preliminary design into a CAD model.


This step is crucial to ensuring that your blueprints:


  1. Will work as intended

  2. Meet your evaluation criteria before they enter the eventual production phase


Your next steps include:

Taking an Intro to Solidworks Course

It’s challenging to design pneumatic or motorized devices when you’re still a newbie to mechanical design principles. The best place to start is with an interactive Introduction to Mechanical Engineering With SolidWorks course.


We’ll teach you the basics of 3D geometric modeling to bring your design visions to life through SolidWorks, the most invaluable program for beginning mechanical engineers.

Tackling Component & Assembly Design

“Components” and “assemblies” describe the two primary moving parts of SolidWorks and CAD. 


The components are the physical materials you’ll add to your workup to bring the physical design to life. If you were designing a dirt bike, for instance, sheet metal, gears, and tubing would be some of the components.


The assemblies enable you to put the pieces together in a way to enhance functionality. For example, you can weld metal facets together and grind down materials to reduce size.

Testing the Design Via Finite Element Analysis (FEA)

Once your design is complete, you need to verify that it works just as you envisioned it! That means running a simulation to test for:


  • Thermal issues

  • Structural problems

  • Vibrational concerns

It’s better to find out that your plastic design would melt or that your chair would crumble under 300 pounds of weight before you allowed your client to market your design.

Establish Design Communication

If you’re simply honing your skill set, take a moment to reflect on your prototype and document your success. 


But if this was a school or client project, your final step of the mechanical design process is typing out a formal report to share your progress.


The key components of a successful design report include:


  • An overview of the problem

  • The intended functions and objectives of the final design

  • Project specifics (timeline, materials, dimensions, etc.)

  • A timeline of prototypes and design phases

  • Graphs, tables, and charts expressing simulation results

  • A step-by-step guide to creating the final product

  • Ethical and safety concerns (for the product and design team)

  • Acknowledgments

In this final step of the design process, details, data, and citations are all crucial. Your design communication should answer any questions your client (or professor) might have and explain any questionable decisions you made 

along the way (like why you chose a lesser-used material over a more common choice).

Conclusion

Whether your next mechanical design project involves 3D printing, mechatronics, or a simple robotic arm, following a consistent design process can help save you a ton of time and money. 


Ultimately though, it's about what works best for you in your current stage. As a beginner, doing and executing is what's important because you will fail. 


And that's okay. 


No one starts out making perfect designs from day #1. 


Fail and fail quickly, and in doing so, learn.  


The design process gives structure to what otherwise can be a chaotic and open-ended journey with a clear lack of direction. But it's not supposed to be restricted, where you emphasize the process more than the results.


Our tip:


Practice honing your mechanical design skills in your free time while you still have some left, well before it comes time to lay the groundwork for your senior design project.


It'll make your life and future career easier in the long run!



Learn more about our mechanical design courses!
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