Top 6 3D Mechanical Engineering Projects to Develop Your Skills and Knowledge Now
We must design for the way people behave, not for how we would wish them to behave – Donald A. Norman
Mechanical engineering projects are the cornerstone of every day activities for well mechanical engineers, but you don’t need to be in industry or into your career to get the benefits they provide for skill / methodology and on the job learning, you can start them now and start gaining/building those benefits.
Mechanical Engineering Projects – Thinking about design.
Every design, as described in The Design of Everyday Things, should have two essential qualities:
- It should be understandable.
- It should be discoverable.
These two points really resonated with me when I first listened to the book on Audible (yes, that still counts as reading!). Since then, design has made far more sense. Applying those principles to the products I see around me helps me recognise well-designed items—and just as importantly, where improvements could be made.
That brings me to today’s topic. I wanted to share and review six mechanical engineering projects from Thingiverse that you can 3D print at home, and explain why I think they’re worth your time. Each one offers a different learning opportunity, and in some cases, I’ll suggest how you might modify or expand them to push your skills further.
If you already own a 3D printer—or are thinking about investing in one—these projects showcase the kind of creative engineering you can explore from home. My focus is on practical, problem-solving designs that demonstrate engineering principles, not just decorative prints.
Skills to develop using Mechanical engineering projects:
- Reverse engineering
- FEA (Finite Element Analysis)
- FIT/Form and Function
- Tolerances (Clearance, Transition and Interference)
- Standardising sizes
- Off the shelf components mixed into design
- Good design practises
- Simulation
- Tolerance stacking
- Geometric tolerances
- Parametric viewing
1. Build-Your-Own Miniature Vehicle Kit
This card-style kit concept isn’t new, but it’s a clever idea. It reminds me of Warhammer figures that come in injection-moulded sprues, where you cut, fit, and glue the parts together. It’s great as a gift and ideal for people who enjoy hands-on creation (something engineers are particularly fond of!).
What I like about this design:
- Requires precise fits for snap-together parts.
- The flat card layout resembles injection moulding design principles.
- Includes compliant features that simulate the real functions of a vehicle.
What you’ll learn:
- Try designing a different vehicle using the same card concept.
- Consider the constraints of size, space, and material use.
- Aim to fit all parts within a fixed card size (for example, a credit card).
- Study fit tolerances and how the parts connect and assemble.
2. Compliant Mechanism Shark Clamp
A simple yet elegant design that incorporates compliance directly into the mechanism. It relies on the material’s natural flexibility to create a spring action. I imagine this design came from plenty of trial and error—a hallmark of practical engineering!
What I like about this design:
- Demonstrates the potential of 3D printing for multifunctional, single-part designs.
- Uses compliant mechanisms to reduce part count, wear, and lubrication needs.
- The “shark” aesthetic cleverly connects form and function.
What you’ll learn:
- Try designing your own G-clamp with a compliant feature.
- Experiment with dimensions, materials, and tolerances.
- Take it further—create a device that includes two compliant elements, such as a racket clamp.
- Consider ways to improve durability and reduce fatigue.
3. Petal Mechanism with Cams
This is an excellent example of combining simulation, modelling, and 3D printing. It features levers, close fits, and a cam-based motion that controls petal movement. The cam itself is more of a follower groove design, making it a fascinating study in mechanical motion.
What I like about this design:
- Compact and well thought-out, using clever geometry and CAMs.
- Demonstrates quarter-turn actuation through precise movement.
- A “print-in-place” project that tests your printer’s tolerance capabilities.
What you’ll learn:
- Explore cam functionality and modify the design to alter petal motion.
- Understand how geometry drives function.
- Learn to design within your printer’s accuracy limits, accounting for clearances and fits.
4. AA Battery Dispenser
This project takes a standard, everyday item—the AA battery—and turns it into part of a clever storage and dispensing mechanism. It’s a great example of reverse engineering and Design for Manufacture and Assembly (DFMA).
What I like about this design:
- Optimised for 3D printing, with no support material required.
- Demonstrates strong DFMA principles by simplifying assembly.
What you’ll learn:
- Study the part geometry, overhangs, and snap-fit features.
- Analyse how components interlock and how fits are managed.
- Reverse engineer to understand clearances and tolerances.
- Consider print orientation and efficiency in your own designs.
5. Wind-Up Gear Mechanism (Card Format)
This project combines gears, a spring, and energy storage—all in a flat card format. The design uses a wind-up key to store and release potential energy, making it an engaging study in materials, strength, and fatigue.
What I like about this design:
- Clever use of compliant mechanisms to store energy.
- Highlights the importance of material selection to prevent spring failure.
- Encourages attention to gear meshing and tolerance control.
What you’ll learn:
- Material selection and properties.
- Tolerances and fit between gears.
- Understanding wall thickness, stress, and fatigue.
- The relationship between geometry, stiffness, and performance.
Resources (Internal) – Engineering Design
Liking this post? there’s more on this subject if you want to learn more:
How to use the Engineering design process
Why do engineers constantly use NDT?
Tighten tolerances and the costs go down?
How important is knowledge of materials for mechanical engineers?
You really need to apply SMED and Poka Yoke Thinking in Fixture Design
6. Combination Puzzle Box
A mechanical puzzle that blends the ideas of a safe and a combination lock. The design uses replaceable number rings, allowing you to customise your own PIN combination. It’s an excellent way to explore mechanisms, tolerances, and the logic behind interlocking parts.
What I like about this design:
- Thoughtful use of a central spindle and rotating rings to control the locking sequence.
- A fine example of integrating mechanical logic into 3D design.
What you’ll learn:
- Combination mechanisms, precision fits, and cam-based movement.
- Understanding sequential motion and functional constraints.
Bonus: SNES Cartridge Dust Cover (My Own Project)
I couldn’t finish without including one of my own. I spent several months developing these SNES cartridge dust covers, reverse engineering the originals and refining the fit until the sleeves were snug but still removable.
What I’d love to know from you:
- What do you like about this design?
- What would you learn or do differently?
Roundup of the Mechanical Engineering Projects
So, there you have it—six (plus one) 3D projects that demonstrate clever, practical engineering design. Each provides a unique opportunity to practise different skills: tolerancing, material selection, compliant mechanisms, DFMA, and reverse engineering.
Exploring these kinds of projects is a great way to sharpen your design intuition and build real-world engineering judgement—all from your own workshop.
Suggested Practice Mechanical Engineering Projects:
Beginner Level:
- Phone/tablet stands (practice fillets, angles, stability)
- Parametric box generators (practice parameters, dimensions)
- Snap-together puzzles (practice clearances and tolerances)
- Tool holders and organizers (practice functional design)
Intermediate Level:
- Mechanical toys with gears (practice mechanism design)
- Articulated prints with living hinges (practice material behavior)
- Customizable organizer systems (practice modularity)
- Functional tools with ergonomics (practice form + function)
Advanced Level:
- RC car components or modifications (practice stress consideration)
- Robotic arm joints (practice assembly, bearings, constraints)
- Complex mechanisms like clocks or automata (practice tolerance stacking)
- Prosthetic/assistive devices (practice real-world problem solving)
Resources (External) – Engineering Design
Here is a list of resources I find particularly usage in any design project I’m doing:
GD and T Basics – A one stop shop to list and understand all the Geometric tolerances used today in industry, with simple explanations (some are long) with illustrations to demonstrate.
Learn Mech – As it says on the tin, head over here to dive into the many different mechanical examples shown and explained on this site.
My Physics Lab – A great interactive website that teaches you many (if not all) the mechanical principles and physics.
Engineering Toolbox – A true repository of engineering (all fields) knowledge, go jump down that rabbit hole!
Engineers Edge – Just like the Engineering toolbox, this site has calculators for many of the engineering principles it talks about, great to working out things.
What are your thoughts? Have I covered everything or is there more you know and would like to share?
I’m always learning and improving this site and my blogs, so please feel free to get in touch with me via LinkedIn or this site to discuss any topics I have covered.
If you’re having trouble finding ways to progress check out these sites filled with free learning tools:
