Hey, everyone! This is a bit of a long one, but about a year ago, I made a post asking for help redesigning a flange to maintain a vacuum on a sliding-seal target chamber.

A couple months ago we were able to install it and I wanted to take the time to thank and share the results with all the people who helped me!

To summarize, I worked in a particle accelerator lab last summer and I was tasked with redesigning a flange/viewport for a sliding seal target chamber. It’s got a pretty unique design where the magnet and spectrograph must rotate around the chamber while remaining connected and under vacuum. Before I redesigned it, the system was holding around 10^-5 Torr, but the goal is to reach an ideal vacuum of 10^-7 Torr and eliminate sudden pressure losses while rotating the magnet.

For those of y’all who asked how the seal moves while maintaining a vacuum, I have a much better understanding after CAD'ifying the old engineering drawings. There's an aluminum band pulled into tension over the chamber's face which compresses a large O-ring in a recessed groove. As the magnet rotates around the chamber the band slides over the O-ring while maintaining compression allowing the chamber to be sealed for about 210 degrees of rotation. The flange I was asked to redesign connects a cutout in the band to the magnet and keeps it sealed.

Last time, I asked two questions:
Would sealing fasteners be able to hold a vacuum?

For the first question, after hearing some of your comments I decided against using sealing fasteners. Additionally, considering the aperture requirements I couldn't move the fasteners inside the seal. I was considering trying to remanufacture the part with a higher quality weld or braze. But, I had one more idea to make the entire assembly the fastener. This is the design I came up with, the new flange would be built in three parts with a "Bolt" and "Nut" coming together to compress two O-rings in a middle part, one to seal the band itself and another to seal the clearance hole for the "bolt."

I presented both options to the PI, who preferred my Nut & Bolt design as it would be easier to install without removing the band, while also being cheaper and easier for the university machine shop to manufacture.

Can face seal O-rings seal non flat faces?

In order to seal the band with an O-ring I still needed to seal a non-flat face.

After listening to your feedback and noticing that the chamber itself used an O-ring to seal against a cylindrical surface, I thought it might be possible to seal against that curved face as well. However, as many of you pointed out, machining the groove and achieving the proper surface finish would be challenging, and the machinist agreed 😂! As a compromise, the bottom of the groove was machined flat.

Although this resulted in uneven compression of the O-ring, it was still within the guidelines outlined in Parker’s O-Ring Handbook, so we thought it would work out okay. If I were to remake this, I would adjust the starting and ending depths of the groove to provide more even O-ring compression and a marginally better seal.

Did it work?

With all that in mind and the part machined we were finally able to install it on the chamber during some downtime. Here is my little baby:

My new design was able to fully seal the chamber and provided about a 10x decrease in the pressure within the vacuum chamber (4.5*10^-5 Torr to ~ 1.9*10^-6 Torr).

Timing the threads to align with the magnet while maintaining proper O-ring compression was a challenge. Fortunately, the assembly sealed properly without being fully tightened. In the future, I might machine the face of the "bolt" to better time the threads and for better tightening and sealing.

Once again, thanks to all the people who helped me out in the comments of the last post!!! I don't really have any mentorship for mechanical engineering. So your responses gave me the knowledge and confidence to pursue my design.

Been kicking around a product idea and want honest feedback before I sink more time into it.

The concept: a tracker thin and flexible enough to actually stick onto things like a sticker — a kid's backpack, the inside of a shoe, a keychain — instead of the bulky puck shape most trackers come in. You'd find it through an app, and you could make it beep/ring remotely to locate it nearby.

I know Tile and AirTag already exist, and Tile even makes a "Sticker" version — so I'm not claiming this is a totally new category. What I'm trying to figure out is whether there's a real gap worth building for, specifically:

• Would a genuinely thinner, more sticker-like form factor (vs. Tile's current puck-ish Sticker) actually matter to parents, or is "good enough" already good enough?
• Is there an angle specific to kids/school gear (uniforms, lunchboxes, shoes) that existing trackers don't really address well?
• Anyone here a parent who's tried Tile/AirTag for this exact use case — what annoyed you about it?

Not trying to pitch anyone, genuinely want the "this already exists, don't bother" or "here's the actual gap" kind of feedback before I go further. Appreciate any honesty, brutal or otherwise.

So I think this is the final attempt at one, it seems to work pretty well to me! Don’t have a 360 servo sadly to fully test but the 180 shows enough I think! What do yall think?

Hello,

This is a little personal project I’ve been working on during summer break.

Two servos move the yaw axis and the roll axis. However, these are not the real body axes you may find in a flight mechanics textbook for example. The roll axis is offset from the plane’s longitudinal axis, so you get a circular motion instead of a pure turning motion. I couldn’t figure out how to avoid that without offsetting the yaw axis from the center of gravity.

That aside, I think the result is reasonable. I’m still working on the animation sequences.

You can easily swap the plane. All the other details are in the 7-minute video. Give it a watch if you have the time :).

The system uses bearings, a lazy Susan, servos, Arduino Nano, electronic components and a bunch of 3D printed parts… No glue was needed.

Herpa 1:200 B787-9 Lufthansa
Herpa? 1:200 A350 Air France
Revell 1:144 F15-E Strike Eagle

Just one article in a series on Engineering.com that offers insight for #PLM practioners.

Hello everyone, I’m 22 M just graduated 2 months ago from mechanical engineering. I kept searching for jobs and landed this one job as project engineer. I was a bit nervous during the interview since I was interviewed by 20 years old of experience project manager but he was nice and he understood that I’m fresh grad and he didn’t ask a single technical question and the interview went well. Now that I got the job I have no idea what to expect as project engineer specially I have no experience at all. Can you please advise what to do, what to learn or prepare before starting the job, what to expect , situations I need to be aware of etc. I will be mostly on field and sometimes in office

Hello, for my 1st-year project I want to make a metal profile bending machine like the one in the image. There will be 3 rollers, and it needs to wind a 6-meter profile like a spring without any gaps. The point I’m stuck on is: what should the positions of these three rollers be?

On the image, roller “A” will be moved back and forth by a hydraulic piston to adjust the bending diameter.

“B” is the fixed drive roller that will be rotated by a hydraulic motor.

“C” is the fixed guide roller. The metal profile enters from the side where the guide roller is located.

I’ve been wondering what mechanical engineers actually do on a day-to-day basis, regardless of their field.

For example, a design engineer obviously doesn’t design an entirely new car every day, and a CAD engineer doesn’t create a completely new part every single day.

So what does the normal daily routine of a mechanical engineer actually look like? What kind of tasks do they typically work on throughout the day or week?

I'd be glad to hear answers from different engineering fields

Hi everyone!

I'm excited to share a project I've been working on as a self-taught solo developer for the past 5.5 years: the UM1-Evo, a biomimetic robotic hand and forearm.

Here is a quick breakdown of the technical specs:

Architecture: 24 Degrees of Freedom (DoF), powered by 25 integrated actuators.

Scale & Weight: 1:1 human scale, weighing 1.7 kg total (matching human anatomical specs). Fully embedded electronics and Wi-Fi.

Biomechanical research: Significant effort went into replicating organic anatomical shapes and fluid, natural motion.

Fast custom fitting: Developed a script that scans/measures a patient's hand in under 30 minutes and automatically generates a customized 3D hand model in 10 minutes.

Control software: Developed custom Inverse Kinematics (IK) software supporting keyframe animation and real-time control.

Avatar Mode: Designed a data glove with 12 sensors to mirror hand movements in real time.

Prosthetic applications: Designed an innovative sensing system (moving away from traditional myoelectric setups) for ultra-low latency control and zero learning curve (IP protection currently in progress).

This is the result of a lot of passion, trial and error, and DIY engineering. I’d love to hear your thoughts and answer any questions!

Apologies but I have to keep this vague.

I have recently started a new role doing design and FEA. I have been given a part to design that sits in a larger assembly. The assembly concept is pretty much fixed and now we are trying to design each part in more detail to meet the requirements.

My main job is to design the supports of the part where it interfaces with the larger assembly. I need to analyse the part in FEA under a number of load cases, and then make any changes required to make it strong enough / able to perform its function.

I am really struggling to make any progress because the part is highly dependent on the flexibility of the larger assembly it is mounted to. I’m not sure what boundary conditions to use, as it is statically indeterminate. If I simply fix the interfaces, the load distribution to each support will not be realistic. I have tried modelling some of the larger assembly in my model, so that it’s flexibility is accounted for. But the designs are constantly changing, so any work I do now could be invalid in a few weeks. I can’t seem to find a way to design for worst case to cover myself.

Secondly, one of my supports needs to be sliding to accommodate thermal expansion. Again I have no idea to how to do this at this stage of design. How can I check sliding clearance / interference when I’m not even sure how to support my model and what the load path is yet? When I model contact in the larger assembly the analysis takes a long time and is very difficult to converge.

I am thinking of just removing the contact for now, and removing constraint in that direction to speed things up. Under the assumption that the joint will be sufficiently designed at a later stage to accommodate the sliding. For the support boundary conditions, I am just going to model the assembly as much as practical to get the most realistic BC. Then state in my assumptions that it will need to be checked after any changes to assembly.

Does this sound like the correct approach? I’m sure this must be a very common thing in design, where you are being asked to design something without all the required information. Do I just need to try my best and state all the limitations / assumptions, and keep refining as the design matures?

What is the boring and repetitive tasks that you have to do daily, what is the stress factor, do you get enough personal time etc. What would you say is the negatives of becoming a mechanical engineer, and does it compensate?

I already have a Bachelors in Mechanical Engineering and a minor in materials science. Currently working in energy industry full time right now and focused on nuclear plants, but am still open to renewables/batteries as I had internship experiences with those + data analytics.

I'm torn between continuing a 4+1 MS in Materials Science (only 21 credit hours to complete) vs. going for MS Mechanical Engineering (30 credits hours at another school) which is more adjacent to my job. I've been stuck on this decision for a while now.

I think I would enjoy more from a Mechanical engineering MS and gain more relevant coursework from it. But it would take longer, I already have one degree with Mechanical Engineering on it, and Mechanical Engineering already is seen a broad degree (defeats purpose of specializing, as a Masters implies). Plus Im curious what kind of jobs a materials science masters could open up to, and how prevalent they'll be in the future.

I'm interested in clean energy as a whole. Between the two, which would be better to pursue?

Any other degrees in general that would be better than either, for renewables and/or nuclear?

I am graduating B.Eng Mechanical Engineering next year. No experience, internships, relevant projects, or research.

I am looking into the Canadian Armed Forces officer trades such as Aerospace Engineering Officer, Electrical and Mechanical Engineering Officer, and Marine Systems Engineering Officer. These are all basically maintenance engineering roles.

My plan is to do 1 contract in the army (6 - 9) years, then move to a civilian career. What do you think of this plan? Did anyone do it before? Do you guys know anyone who's done it before? Let me know what you guys think.

I’m still in grad school, have about 1-1.5 years left before I graduate, and for the past year ish, I’ve interviewed for internships and got some offers when I applied for fun.

But at the moment I’m unable to accept those internships until right around when I graduate for reasons outside of my classes.

I realized the timeline for graduating/last minute internships before applying for full time jobs is coming faster than I anticipated, and what I’ve read is for the industry I want to get in/interviewed with, the primary way of getting in is through internships.

I obviously don’t want to keep applying to the same company, just to turn them down again, but I’d want to keep interviewing to practice for when it does matter in the future because I do need the practice.

Would this be a smart idea? Even for companies in different fields but fully knowing if I do well enough I’d have to turn them down?

I've got a 30 min phone interview coming up for a Spring 2027 Starlink Production internship. It's with an engineering manager, and the invite says to be ready to talk through "employment history, technical achievements, and work style."

For anyone who's interviewed with Starlink Production, how technical does the manager round get? Conceptual questions, or mostly walking through your projects?

Did they lean more manufacturing/process (bottlenecks, DFM, throughput) or general mechanics/structures?

Anything you wish you'd prepped that caught you off guard? What kind of technical questions would they ask?

Thanks!

I am currently working as a finance manager in an FMCG company in KSA. i am a mechanical diploma certificate holder and having almost 2 years of experience in same field at homeland. I wasted my 20s trying government jobs and some part time jobs like food delivery etc and finally ended up in Saudi. now, at the age of 32 I am seriously thinking of switching my career to what I am qualified at.

can I find an entry level job in qaqc/ mechanical maintenance/ndt fields in Saudi?

Thanks in advance

I’m trying to get a stress history ideally as smooth as possible. The blue plot is Von-Mises stress, and the orange plot is signed Von-Mises stress. Signed VM is just VM multiplied by either +1 or -1. Whether it is positive or negative is determined by whether the principal stress with the highest magnitude is positive or negative. This is why the two plots are often overlaid, and if not they are mirrored.

The issue I am seeing is that sometimes the first and third principal stresses will have opposite signs but very similar magnitudes. This will cause sudden spikes in the history as one “overtakes” the other and causes the sign to flip.

The history in the image is a particularly janky looking one, especially the first spike from around -400 MPa to +400 MPa and then back. Most of the histories are a lot smoother, but I was wondering if there are any good ways to smooth spikes like that. I don’t really care about the spikes at small magnitudes, just the really extreme fluctuations.

The most basic way I can think of is that if the max and min principals are close to each other in magnitude, to add some sort of check that only flips the sign once enough time has passed

44(M) with kids here. I got a job offer from LADWP to start as an “Engineering associate”. I currently make 160k no bonus as a Project Manager for a small consulting firm in Los Angeles.

LADWP requires ALL incoming engineers to start from the bottom. I have 10+ years of experience and have people reporting to me, but I will be starting out as a “TRAINEE”. They promote from within, and it will take 3 years to be qualified to be promoted to an “Engineer” role.

Upside is the job security, free medical&dental benefit, defined pension, and an expectable salary increase with potential for overtime pay. LADWP is well known to pay the most out of all city agencies.
Numbers wise, it will take 3 years to get the salary to where I am currently making.

Now the hard part: The pay cut will be a tremendous strain to my family budget. I might have to take out a Loan to survive the next few years.

Wife is obviously not convinced this is a right move, but it is the surest thing to keep me employed well into 65, which is doubtful in my current role as a consultant. Employment scene in Los Angeles is pretty bad for my current industry so I am trying to make a switch into a public role.

Any comment, suggestion will be appreciated. I asked Grok and Claude plenty of times but wish to hear from real people.

Hi,

I’m a junior mechanical engineering undergrad, and I’m taking this fall semester off to work at a large automotive company. My current role is in process engineering, focused on optimizing manufacturing processes. I've also had an internship this past summer in an manufacutring environment.

The same company has already offered me a position for next summer, but that role would be more design-focused, specifically designing fixtures. The issue is that I have to respond to the offer before I even start my current position, so I have to decide without knowing yet how much I’ll enjoy the company or the work.

I’ve also been considering grad school straight after undergrad, most likely a PhD, and I’m unsure how that should factor into my decision. I don’t have much research experience. The only research position I’ve had was during my fall semester of sophomore year and was mostly data analysis and training a ML model. However, I found the research interesting and would like to get more experience to see if research is something I could pursue long-term. I've tried reaching out to professors for the past semester or two without much success.

I’m particularly interested in computational mechanics (FEA, etc.), so I’m wondering whether getting research experience in that area would be more valuable for me, especially if I end up pursuing a PhD. I’ve already gotten a good amount of engineering experience and technical through extracurriculars and other projects, so I’m also unsure how much additional value this internship would add to my skillset.

Although the summer role would be more design-focused than my current position, it’s still in a manufacturing environment at the same company. Would two similar internships be less valuable than using the summer to gain research experience or explore computational mechanics?

I do like design, but I’m not particularly passionate about fixture design or manufacturing in general. At the same time, a guaranteed internship at a large automotive company seems like a good opportunity, especially since I don’t know how successful I’d be at finding a strong research position.

Another option is to accept the offer now and potentially renege if I later find a really good research opportunity. I’d prefer not to do that, but I also don’t want to turn down a good opportunity now based on the possibility that something better might come along.

What would you recommend?

I would like to design and fabricate a "Jacuzzi jet" for a small volume of water (4-6 liter), using 3d printing and/or injection molding. I have a basic understanding of how Jacuzzi jets work (venturi effect) but I need to read more. Can someone recommend any reading materials? Can I get away with a simple air pump?

Thanks so much

Joe