I know there is more to it but to keep the question simple. What size engine(displacement) would take full advantage of a 1” I.D. Intake restriction? Say for example a small 5hp engine would be ok with that. But a 2000cc engine would be struggling and starving for air. What is the perfect engine size that, at maximum rpm, a 1” I.D. “Throttle body” let’s say, would be adequate. It can be 1 piston or 20, doesn’t matter.

I hope this makes sense.

Can anybody that works with APQP and PPAP for bulk materials point me to some resources that explain the differences in methodology compared to discrete part manufacturing?

I’m trying to incorporate the methodology into bulk liquid chemical manufacturing and the majority of the information revolves around physical part manufacturing. I’m especially curious about differences in design FMEA, and Measurement system verification and process capability (because production is in bulk manufacturing 30 batches for verification isn’t feasible on commercial scale process equipment).

Any help would be appreciated.

I can’t get tensile bar samples from the manuf in time, can I just cut down a plaque sample and tensile test those? Or maybe just use the plaque, although I worry this may be too large (4x6”x3mm or so)

I’m only checking for this materials comparability with an oil. I don’t need to know the “true” tensile values, only a ratio between that of the original and the oil. Really to see if the oil significantly affects it.

Can any profile be used for tensile testing? Assuming the samples being compared are uniform.

Hey all, trying to source this piece for a personal project. I've tried different combinations of the words "elbow hinge connecting rod ball socket" on Google but no luck. This one is particular as it has the slot in the female section, which allows the male end to pivot in the horizontal axis.

Any ideas appreciated!

Intro

Welcome to the weekly career discussion thread, where you can talk about all career & professional topics. Topics may include:

• Professional career guidance & questions; e.g. job hunting advice, job offers comparisons, how to network

• Educational guidance & questions; e.g. what engineering discipline to major in, which university is good,

• Feedback on your résumé, CV, cover letter, etc.

• The job market, compensation, relocation, and other topics on the economics of engineering.

[Archive of past threads]

Guidelines

1. Before asking any questions, consult the AskEngineers wiki. There are detailed answers to common questions on:

• Job compensation
• Cost of Living adjustments
• Advice for how to decide on an engineering major
• How to choose which university to attend

1. Most subreddit rules still apply and will be enforced, especially R7 and R9 (with the obvious exceptions of R1 and R3)

2. Job POSTINGS must go into the latest Quarterly Hiring Thread. Any that are posted here will be removed, and you'll be kindly redirected to the hiring thread.

3. Do not request interviews in this thread! If you need to interview an engineer for your school assignment, use the list in the sidebar.

Resources

• The AskEngineers wiki

• The AskEngineers Quarterly Salary Survey

• For students: "What's your average day like as an engineer?" We recommend that you spend an hour or so reading about what engineers actually do at work. This will help you make a more informed decision on which major to choose, or at least give you enough info to ask follow-up questions here.

• For those of you interested in a career in software development / Computer Science, go to r/cscareerquestions.

Apologies if this falls under the "how something works" rule. If so no problem if it has to be removed.

I have a 12mm shaft with a 4mm key. Not sure of the best way to fix a gear to the shaft. RPM is something like 0.3. with roughly 50Nm of torque. pretty sure a grub screw would hold it, but needs to be bulletproof due to the environment (sea bed).

The shaft in question:

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https://preview.redd.it/kvoltkiz494c1.png?width=1058&format=png&auto=webp&s=a3768651d061e1ef2264eb41cf4ddb37cdc10a39

Here is the orientation of both gears when in use:

​

https://preview.redd.it/5hk88693594c1.png?width=1107&format=png&auto=webp&s=864cbede6cf47229db089f0a43fdd7d352b0e7a5

​

I've been looking at getting a Tig welder for a while but I've been distracted by the idea of getting a laser based welder. Has anyone here used both and if so what was your opinion of the laser welder, was it worth it?

Edit: update, a lot of good points made -concerns that the Cn laser will be rubbish and can't be that cheap

• laser has a short to no leaning curve to have "rockstar welds"

-laser safety a big a legitimate concern.

-laser setup is a longer, wire feeders etc.

-tig are more versatile and can do more welds with.

-tig are cheaper

-tig has a steep leaning curve

-tig is harder to weld thin metals.

-tig is established and spare parts and consumables are common and cheap

-laser welder head is quite large and makes it difficult to weld in tight spots.

Now I'm leaning towards Tig as a best multipurpose case.

So I would now, has anyone got a laser welder and how expensive is it to operate? For example Tig uses electrodes and argon, these are cheap.

Our ECN procedure is thus:

• Make changes to the assembly model
• Open up the print in Inventor so it updates with the changes to the model, including revision # and whatever changes have been made to the components or the BOM
• Save the old PDF as a record and replace it with the new print PDF
• Make changes to the BOM or assembly description in our MRP
• Document the changes and send out the ECN

This turns into a huge nightmare when a change affects a large number of assemblies. Especially since material variations of assemblies have their own assembly models (assemblies function as the source of all information and engineering data that gets pulled in to the print via standard and custom parameters). We do not have Vault... :(

Currently faced with the prospect of replacing a component in hundreds of assemblies... it's a brute manual process that is mind numbing. What does everyone else do? Does this sound right to you all? Do you have automation scripts that you use to handle bulk changes like this?

Thanks

Hi r/engineering I’m in the early stage of my ME career, about 3 years exp. I find myself with analysis paralysis often- what I mean by this is I get nervous submitting analysis work and reports. I get overwhelmed with making sure every detail is correct and as a consequence I miss deadlines and my work takes 2-3x longer to complete than some of my peers. For things like drawings, cfd/fea analyses, presentations/reports. Granted, all my peers are senior level mech engineers. I feel like it’s a mix of impostor syndrome, undiagnosed adhd, and anxiety. Does anybody have any experience overcoming this feeling?

I see hybrid vehicles with better mpg compared to gasoline only models. However, the hybrid models tend to have lower horsepower which I wonder if this may be the real reason for better mileage. Yes there is an electric motor that can recapture energy through regenerative breaking, but it comes with the cost of lugging around 400 lbs of extra equipment. Is it all a gimmick? Would we be better off driving gas vehicles with lower HP to get better efficiency? I’m just curious what the engineers think.

How do you guys stand to sit and draft for 5 days a week? I always enjoyed drafting and drawing in college, but staring at a computer for 40 hours a week and the same project is making it extremely hard for me to focus. I’m really productive Monday and Tuesday and feel like I do stuff Wednesday-Friday, but definitely feel I don’t do much drawing wise. Does this get better the more I do it? I have had other engineer related jobs but nothing straight drafting before

So I need to convey up to 45 ft of 85# rail at around 100 - 150 fpm. Net weight of that section being 1275lb. Roll diameter is ideally 6-8 inches. Coworkers told me to just use roll radius and lbf of mass, but it seems excessive and requires a rather large motor that exceeds the dimensional constraints I'm working with. Other sources claim I only need to overcome friction of bearings (208 series on a Dodge flange bearing). I've come up with the torque in many ways and I'm always getting something that seems disproportionate in terms of gear motor size, based on what I've seen in other similar applications.

I'm at the point where I've confused myself and I need to get this right or I'll waste a lot of money. Any help is appreciated greatly!

Conveyer table info:

Up to 7 idler rolls, as many as 3 powered rolls (for longest section of material). On 6ft center distance between rolls.

I have found some sources claiming that the gearbox on a large wind turbine may not last beyond 36 months. I’d like to see if there’s someone familiar with gearbox failures, and maybe confirm this.

So, while I am waiting for the Drew Marine guy to reply to my inquiry, I figured I would posit it here:

I am testing water that is to be used in a high pressure (900 psi) marine boiler. The distilling plant is not online so we are using city water through a “rainmaker” which has a resin and carbon filter. The color spectrum for the comparator is shades of blue from clear to dark blue with an associated ppm reading. My test results are coming back yellowish-brownish instead.

Does anyone here have an idea as to what could cause this? I have tested four times using an open test kit and a brand new test kit and get similar erroneous results each time.

EIT in BC here. Is there a con to writing the NPPE exam even though you're not close to applying to become a PEng? I'm still working on filling out my experience section and probably about 6-12months from completing that. Id like to get the NPPE exam done with, is it ok to take it early? Wondering when other professional engineers wrote the exam.

I’m looking to spec a color for cylinder stops designed under ISO 10533:1993 and the standard just says they have to be red. What shade of red should that be? Is the shade defined by another standard? I’m having trouble finding anything specific.

Intro

Welcome to the weekly career discussion thread, where you can talk about all career & professional topics. Topics may include:

• Professional career guidance & questions; e.g. job hunting advice, job offers comparisons, how to network

• Educational guidance & questions; e.g. what engineering discipline to major in, which university is good,

• Feedback on your résumé, CV, cover letter, etc.

• The job market, compensation, relocation, and other topics on the economics of engineering.

[Archive of past threads]

Guidelines

1. Before asking any questions, consult the AskEngineers wiki. There are detailed answers to common questions on:

• Job compensation
• Cost of Living adjustments
• Advice for how to decide on an engineering major
• How to choose which university to attend

1. Most subreddit rules still apply and will be enforced, especially R7 and R9 (with the obvious exceptions of R1 and R3)

2. Job POSTINGS must go into the latest Quarterly Hiring Thread. Any that are posted here will be removed, and you'll be kindly redirected to the hiring thread.

3. Do not request interviews in this thread! If you need to interview an engineer for your school assignment, use the list in the sidebar.

Resources

• The AskEngineers wiki

• The AskEngineers Quarterly Salary Survey

• For students: "What's your average day like as an engineer?" We recommend that you spend an hour or so reading about what engineers actually do at work. This will help you make a more informed decision on which major to choose, or at least give you enough info to ask follow-up questions here.

• For those of you interested in a career in software development / Computer Science, go to r/cscareerquestions.

I’m an engineer who works 4 on 4 off in the uk. (2 days 2 nights) in the food industry.

I want to start contracting on my days off but I don’t know where to start or where to ask? Any ideas? A lot of contracts I have seen are for full time and months at a time.

Thanks

Disclaimer: This is not some perpetual machine idea. I know that we need to put some energy into the system to do some work. There is no free energy

Do, my basic idea is to connect a sterling engine to a heat pump.

The max efficiency of a heat pump can go upto 400% and not sure but read somewhere that sterling engines can give upto a maximum of 60% efficiency(i think in gamma configuration). Now if lets say theoretically we are able to transfer that 300% of energy from the heat pump(from the 400%), into the sterling engine then 300% x 60%, thats 180% energy generation. So that would mean if this ideal system would work, for every 1 unit energy we put into the working parts, we can get 1.8 units of energy back. Obviously, the extra energy is comming from the air heat or from some sunlight concentrator or burning some fuel for the heat exchanger of the heat pump.

I tried to work out the thermodynamics but I am not a mechanical major so cant get my head arround it.

P.S. - If someone thinks this is possible, i would be happy to create a discord channel and work out the equation, materials and thresholds needed to make it possible. Just need some mechanical and meterial engineers.

Australia just introduced a new market called 'very fast FCAS' which means that if you have an electrical load, you can be paid if you give the energy market operator the ability to switch it off immediately. They won't necessarily take control often, but if there is a spike in demand, they will turn your load off while the gas power plants or whatever have time to get going.

I heard that large-scale computing tasks (they might use services like AWS Batch) are very energy-intensive. Tasks like training a machine learning model, genomic sequencing, whatever.

My question is this. Would it be possible to rapidly lower the power consumption of a large-scale computing task without losing progress or ruining the data? For example, by lowering the clock speed, or pausing the task somehow. And could this be achieved in response to a signal from the energy market operator?

I feel like smaller research groups wouldn't mind their 10-hour computing task taking an extra 10 minutes, especially if the price was way lower.

Thanks!

There are a lot of experiments in my lab, and I wish I had more control over certain inputs. An example would be controlling voltages applied on certain instruments where I can type in the exact voltage I want, instead of playing with a very sensitive potentiometer. Other brief examples would be controlling liquid-pump rates, flow-rates, etc..

Is LabView the best option for this, or what are other popular programs/software people use for controlling parameters in their experiments?

It's an order of magnitude difference with, from what I can observe, marginal benefits. When I say marginal benefits, I mean "pendant arms support from above instead of directly behind, and lower instead of lift the monitor". This really seems to be the only difference. What gives? Is a rectangle so much more expensive? Is it because it's almost a monopoly between Hoffman and Rittal?

Over the past few months I have noticed some concerning damage to the I-90 overpass at the I-90/I-95 interchange. I have sent photos to MassDOT, but figured a second opinion wouldn't hurt.

The damage is located at 42.341010, -71.260916. What seems to be a substantial amount of concrete (maybe 20-30 ft. tall?) has fallen off multiple support columns and piling up at the base of the overpass' support structures. The rebar is rusting through, and the damage has gotten wider since I first noticed it a few months ago. This is happening on at least two support columns. I finally had an opportunity to try and take a picture of it from the passenger seat.

​

Second pillar with damage

I was trying to get a shot of both pillars, but I just didn't get the timing quite right - here's a photo from Google Street View - this shows how the damage on the first column is worse.

​

Google Street View

EDIT: Another crop-in on the left support from the screenshot above - will try and get some better pics next time.

​

Added some lines (on mobile, apologies) to try and show how the concrete is crumbling off multiple sides of the support.

To the professionals - how alarmed do these photos make you?

Hi all, I've got a system that needs testing in a temp controlled bath (-2 oC to 30-ish oC). It's quite large, 230mm OD x 800mm long, and it'll kick out 1.5-2kW of heat.

The only temp controlled baths I can find are the small lab sized ones. Does anyone know of a company that makes big ones? Cheers!

Intro

Welcome to the weekly career discussion thread, where you can talk about all career & professional topics. Topics may include:

• Professional career guidance & questions; e.g. job hunting advice, job offers comparisons, how to network

• Educational guidance & questions; e.g. what engineering discipline to major in, which university is good,

• Feedback on your résumé, CV, cover letter, etc.

• The job market, compensation, relocation, and other topics on the economics of engineering.

[Archive of past threads]

Guidelines

1. Before asking any questions, consult the AskEngineers wiki. There are detailed answers to common questions on:

• Job compensation
• Cost of Living adjustments
• Advice for how to decide on an engineering major
• How to choose which university to attend

1. Most subreddit rules still apply and will be enforced, especially R7 and R9 (with the obvious exceptions of R1 and R3)

2. Job POSTINGS must go into the latest Quarterly Hiring Thread. Any that are posted here will be removed, and you'll be kindly redirected to the hiring thread.

3. Do not request interviews in this thread! If you need to interview an engineer for your school assignment, use the list in the sidebar.

Resources

• The AskEngineers wiki

• The AskEngineers Quarterly Salary Survey

• For students: "What's your average day like as an engineer?" We recommend that you spend an hour or so reading about what engineers actually do at work. This will help you make a more informed decision on which major to choose, or at least give you enough info to ask follow-up questions here.

• For those of you interested in a career in software development / Computer Science, go to r/cscareerquestions.