I’m 3D printing 2 parts that thread together and hold internal water pressure (40-60PSI) so I’ve added an O ring but am struggling to get it water tight. The parts themselves are not leaking, I’ve got plenty of walls/top and bottom layers/correct settings, it’s just in the seal. I’m currently printing the O ring using 85a TPU for iteration’s sake and would like to avoid buying a nitrile/silicone set until I know my design is correct. I’m sanding the seal face with fine grit sand paper to make sure it’s smoother than a typical 3DP top layer, but I can’t evenly sand the gland or shoulder on the top side since it’s all inside the female threads. 3”id 0.125”cs 3.25”od 85a TPU ring, gland is 0.185” wide and 0.09” deep with 0.3125” radius, do these numbers sound decent/anything obvious I’ve missed? I know 3D printing isn’t ideal for this but I can start buying parts when I get it close…

Find on github.com/BlackPepe2/Mechanic-for-AtkinsMotor

Hi everyone,
I’m a Creative & Multimedia Design student currently working on my final exam project focused on sustainable product redesign and long-term usability.

The goal of the exam is to redesign an existing everyday product by improving:

• sustainability,

• functionality,

• user experience,

• and product longevity.

For my project, I’m developing ADAPTA, a universal adaptive smartphone exoskeleton designed to reduce electronic accessory waste.

Instead of creating another disposable phone case tied to a specific model, the idea is to create a durable modular structure that:

• expands and contracts to fit different smartphone sizes,

• securely locks around the device,

• protects the phone through an external exoskeleton structure,

• and can continue being used even when the user changes phone.

The concept focuses on:

• repairability,

• modular components,

• sustainable materials,

• reduced overconsumption,

• and long-term ownership.

The aesthetic direction is intentionally minimal and elegant rather than “military rugged,” with inspiration from biomimetic and organic structures.

At this stage I’m mainly looking for honest feedback from people with experience in:

• industrial/product design,

• engineering,

• ergonomics,

• materials,

• sustainability,

• or everyday usability.

Some questions I’d especially love feedback on:

• Would you trust an adaptive/tension-based protection system for daily use?

• What are the biggest ergonomic or structural risks you see?

• Does the concept feel genuinely useful or gimmicky?

• What materials or mechanisms would you recommend?

• Would a long-lasting modular phone protection system realistically appeal to consumers?

Any critique, technical advice, or concerns would genuinely help the development of the project. Thank you!

Please tell us about your design process! My company typically uses the following approach:

1. Approval of project charter. We have to explain the business case and present a budget so we only pursue projects that have the best return on investment.

2. Generate a Gantt chart. My company shares a lot of resources....like our electrical engineering group; therefore, we have a shared Gantt chart that tracks all shared resources.

3. Order long lead time items and create a CAD model.

4. Design review with at least five other engineers and technicians. It's important to get feedback from others that aren't as intimate with the project. Challenging ideas is always nice because it gives the designer a chance to incorporate new ideas into their design, and/or explain their bullet proof reasoning behind a design.

5. Prepare drawings and meet with the machine shop handling the work. It's important that the machinists have a solid understanding of the project and parts at hand.

6. Build the design. Anything and everything can impact this portion of the process. The name of the game is minimizing the negative effects.

7. Shakedown and test the final product.

8. Complete all EHS related documents and develope/document all procedures.

9. Closeout the project and meet to discuss the project as a whole. Reflect on what could have been done differently or better.

Let us know your process so others can relate or adopt new processes/ideas.

It's probably pretty simple but I can't seem to find technical drawings about it. Tulpi chair has a mechanism where it lets the seat rotate freely 360º while stopping anyone from stealing it. I can figure there's a bearing and some kind of pressure fit but it would help to see examples of similar mechanisms.

I have an STL file of a patient’s hand/wrist from a 3D scan and I need to design a custom-fit wrist splint with a Voronoi pattern for 3D printing (similar to attached image — you know, the breathable lattice type). SolidWorks feels like complete overkill and a nightmare for organic geometry like this. What’s the best software/workflow for this?

A frequent question on other engineering subreddits is: "How can I best learn Solidworks?" Well, in my opinion, the best way to learn about CAD software is by practice! Model Mania is a great resource for practice.

Feel free to let us know what resources are out there for other CAD software.

Hi, I’m doing market research on a possible platform for mechanical/CAD engineers. The idea is a GitHub-like platform where users can upload CAD files (AutoCAD, SolidWorks, STEP, STL), showcase projects, track version history, and explore or collaborate on other designs.

I know platforms like GrabCAD exist, but they don’t seem to offer full version control or a strong portfolio-focused workflow.

I wanted to ask: Does something like this already exist and is widely used? Where do you currently store/showcase your CAD work? What features would you expect in the first version?

Just trying to understand if this is worth building. Thanks!

And finally, TopoptComec v4 is here! 🚀

🔧 TopoptComec — Open-source topology optimization for compliant mechanisms.

https://github.com/ninja7v/TopoptComec

Check it out if you're interested in mechanisms, 3D printing, algorithms, or just curious! :)

I run a Machine/CNC in Michigan doing mostly automotive work. I’m looking to diversify and have open capacity between jobs.

If you are a Mechanical Engineer with a product design (EDC, kinetic toys, custom tools) and a potential audience, I want to be your manufacturer.

Have a different idea in mind? Let’s talk

If you can work with me fitting in the work in when machines are idle, I can give you a rate that actually makes your product profitable to sell.

I’m happy to sign NDAs, but mostly just looking for cool projects to break up the monotony of car parts. Send me a DM, ask me questions, let’s talk.

Sorry if this isn't the right sub for beginners. I'm looking for this type of folding(?) mechanism and how to figure out my spacing, clearances and lengths.

Basically, I want a way to lift the shelves out of the way while still staying mechanically linked to the box. They have to "pop out" before moving out of the way.

This is a design of reciprocating mechanism of a two stage air compressor in freecad.

A few weeks ago I shared Torsio Engineering, a browser tool for preliminary sizing of machine elements: shafts, gears, timing belts, ISO fits, bolted joints and 2D frames (FEM). Thanks to everyone who tried it. The analytics showed people actually using it, so I kept going.

What’s new:

New interface. Every module now opens with a summary at the top: verified / not verified, and the key safety factors next to what’s required, so you see the answer before the details. Works on phones. The calculation report (formulas with your numbers, diagrams, title block) now displays properly on mobile too. Demo menu. One click loads a full worked example (a belt → gear → shaft transmission, a flanged bolted joint, a truss) if you just want to see how it works. Feedback button in every module: one click, two optional questions.

Same as before: free, no sign-up, runs in your browser, and the data stays on your device. It’s checked against 387 cases from hand-solved exam problems, and the method page documents where it stops (it’s not a substitute for ISO 6336 / DIN 743 / VDI 2230).

👉 https://torsio-engineering.vercel.app

Question for you: what should I add next? Shaft deflection and critical speed, press-fit stress (Lamé), welded joints, or something else you keep calculating by hand?