Call for Engineers: Tell us about your job! (2020)

Hi, I graduated from University 3 months ago and finally landed my first interview that will happen in a few days time. I have forgotten a lot of the stuff I learnt in school and have been trying to revise as much as I can. However, I am still feeling anxious about my knowledge regarding my potential role (FEA Engineer).

Any advice on how I can better prepare myself for the interview? in terms of knowledge or behaviour during the interview.

I also need advice on how to sell myself better as I dont have internship experience.

Hi,

So making remote firework lighter.

How many volts/amps would I require to heat up 0.7mm nichrome wire connected to an 8 meter length of 2.5mm single core copper cable

Thanks

I graduated as an engineer and have been working in IT for about a year now. Lately, I’ve been feeling stuck in a cycle of enabling businesses, but I’m craving something more creative and novel. I want to break out of this loop and push myself into exploring new topics — ideally, something that hasn’t been done to death already.

The issue I keep running into is that every time I get excited about a new idea or topic, I end up discovering it was already explored in research papers from a few years ago (like 2020 and earlier). I really want to find something fresh and challenging, where I can explore new ideas and even work towards publishing a research paper.

Does anyone have suggestions on emerging or unsolved engineering problems that I could dive into? I’m looking for something where there’s room to innovate.Preferably in Distributed computing.

Thanks in advance!

Some people explained to me that the design of loitering munitions like the ZALA lancet is to maximize terminal phase guidance accuracy, however both the Israeli and Iranian loitering munitions use 90 degree x wings, only the ZALA lancet use a wing that is more like a biplane. What advantage does this offer in terms of aerodynamics?

What is the best/correct anti-seize to use to prevent/reduce galvanic corrosion of aluminum when installed against a steel part?

To clarify, I'm not talking about threaded fasteners. Imagine something like aluminum wheel rim against a steel brake rotor/hub on a vehicle for example.

I'm 3d printing a mini wind turbine and everything I read says that the standard three blade wind turbine is the most efficient, but in my head a savonius style wind turbine seems like it would spin faster with with less wind, at least for the scale I'm working with. I'm not an engineer, though, so maybe I'm completely off base.

I apologize if I'm not using the right flair, I'm new here. I guess it's partly mechanical and partly electrical...

I have a number of smaller diesel engines (<60kw), now needing to operate in area where there is a nonzero risk of having natural gas making it to the intake and causing a runaway. So, I'm planning on adding positive air shutoff valves.

The purpose built valves are several thousands of dollars and fail-safe is an "optional feature". They're butterfly or gate valves between the filter box and turbo, but I'm trying to think ways to balance cost, supply and safety.

My first thought was to take an off the shelf mechanical throttle body and run the cable to a box with a pull knob and an electromagnet. Use an electromagnet to hold the throttle body open; Wire the electromagnet in with the EPO. Reset requires the operator to pull a knob while the magnet is on. Only custom parts are non-wear items that connect the cable, knob and magnet together.

I was also thinking about one of Honeywells air damper designs, but that might be out of my realm of capibility. A motor pushes against a spring and rotational damper. While the motor is turning the butterfly is held open, and when it stops the spring closes the butterfly. I love this idea because it allows for remote reset but I might not find the damper and spring off the shelf, and I'm not sure I can trust this to close every time all the time.

What idea do you think is best here? Do you have any better ideas?

I always get anxiety at my job when I think about ordering any sort of hardware, for instance, screw sizes, piping sizes, nominal stuff, course/fine threads, etc. How do I get over this? Is there any sort of guide out there that will help me remember this kind of stuff or something I can go to when I have questions about sizing and knowing if something will fit? I am constantly afraid I’ll order the wrong size and look like a complete dumbass.

Usually, PETN or other high explosives are used as the dispersion charge of thermobaric fuel oil-air explosives, how viable is the use of a small amount of compressed oxygen as a dispersion charge? Instead of 100 milliseconds to achieve the ideal stoichiometric ratio, it could lower it by a couple milliseconds and improve safety.

I have a medicine cabinet that has two "drawers" that don't pull out normally but "rock" on a pin set.

These drawers were placed when the cabinet was assembled so they cannot be removed unles you dismantle the entire cabinet or damage it somehow.

I can no longer close the "drawers' because the tube of toothpaste is behind it and preventing it from shutting properly.

There is SOME room to perhaps get a FLEXIBLE grabby device. KInd of like a claw. HOWEVER, most of the flexible claws are tiny little devices and are not big enough to grab anything large.

All the larger ones are FIXED and stiff and won't be able to reach behind.

IS there ANYTHING that I could use that is FLEXIBLE and could grab the object so I could pull it out? The typical small claw object probably would work IF it were larger...

Thank you in advance!

Kinda new to this aspect of mechanical design, but I was thinking of designing and 3d printing a gearbox for an emotor which should overall lift 1lb vertically a distance of about 4ft at a rate of about 1in/sec*. What kind of "gain" can I shoot for? IOW, what should the motor by itself be capable of?

Also, is it sane to want to 3d print something like this? Will it last more than a few months, and will the tolerances be close enough to keep if from jamming? I expect to run it 2-6 times a day.

Thanks so much

Joe

*portfolio project

Hello and thank you in advance for any advice/help.

I am in the final stages of prototyping a design and I am looking into how best to manufacture them. Attached are some pictures of the parts, these are 2/5 of the parts. but these two are probably the most complex. The Bigger one is the enclosure and the little one is a lever with a handle. The enclosure is about 45x60x20 mm and the Lever is 25x48x25

https://imgur.com/a/oqxu995

My question is what's the best way to manufacture them? I am looking to do a small production run of them ~500 and then if all is successful do a large production run of 1000+. I am not set in these numbers but just some examples. These are going to be part of a belt buckle and I need them to be able to handle stress up to about 100-150 lbs. I believe Aluminum is the more cost effective choice but Steel would be the stronger choice.

Ive looked into MIM and Die cast, stamping but i have no clear direction to which way to go. Of note, I am attempting to get these manufactured in the US as well. Thank you!

Pictures here: https://imgur.com/a/xjaw1Iu

So this is a wooden frame I poorly made for a model railroad. Its about 3 by 5 feet using 5” by 1” wood for the frame. There are some supports going across that hold the 2” foam-board. It has no resistance to twisting. This occurs if I lift up one corner and the foam-board twists and everything on top creaks horribly.

I also am looking for a way to attach some legs. In the picture you can see I tried to use some screw on legs but they were horrible and somehow worse than the scrap wood ones.

Coflow jets were invented in the 1960s, electrostatic flow generators around the same time. They offer benefits in every way, from increasing the L/D ratio to delaying stalls by nearly 10 degrees AoA. VTOL and SVTOLs should be the ideal platform for this tech, yet it's never used? Why?

Hello, engineers!

I recently came across an A-frame cabin with adjustable piles, and I want to ensure they are structurally sound before proceeding with the purchase. I have attached a photo of the piles for reference.

Here are my questions:

1. Visual Assessment: Based on the image, do you see any immediate signs of damage or concerns regarding the piles.

2. Soil Suitability: The property is in Missouri and I’ve learned that the soil in the area is primarily Menfro series, which is well-drained and stable. Does this soil type generally support adjustable piles effectively?

3. Maintenance History: What specific maintenance or inspections should I ask the current owner about?

4. Signs of Trouble: What are key indicators I should look for to assess the piles' health?

I appreciate any insights or advice you can provide! Thank you!

pile image

I've seen a few motors for rolling curtains on Amazon (like so; https://www.youtube.com/watch?v=ojfL9XWOEgY) but they're all pretty close to the edge of my current budget and probably overpowered for my application. Furthermore, I might not mind designing a gearbox as a portfolio project. I found moment of inertia equations for vertical loads, but will those work for a curtain? It seems like the load would decrease as the curtain retracts

Thanks so much

Joe

This is for my MSE people out there. My understanding of hardening is it shouldn't come into play until the plastic region of a material. So why do we see hardened blades fracture when dropped before tempering? Do impulse loads affect the material differently than a steady tensile load?

If someone can explain this in thorough agonizing detail, I would be very happy.

I'm replacing worn out caged linear ball bearings which suspend a 1.5hp circular saw on a sliding gantry. It swings a 14" blade at, I don't know, RPM. I'll mostly be cutting wood and occasionally aluminum or steel (this, probably swinging an 8 1/4 or 10" blade)
Assume only very occasional cleaning and hobbyist frequency of use, not commercial / industrial.
The stationary 'arm' of the gantry uses two hardened and ground steel rods on each side. Ditto the carriage - two hardened / ground steel rods on each side. Between them lives a floating linear bearing cage of 1/2" ball bearings.
I think I'd like to use a plastic rod in place of the caged bearings. Before you ask, this is because the cages are completely wasted and the saw doesn't move very smoothly. Replacement parts do not exist.
The rod would be secured fore-aft by a 1/4"-20 longitudinal bolt at each end. X and Z axis, it's sandwiched between steel rods (arm and carriage) themselves fixed against cast aluminum.
Stiffness, slipperiness, and wear resistance seem like the high priorities. If need be, I'll machine the diameter down till I get the desired fit. Room temperature between 20* and 105* F, never more than 3 ft / s, cycle rates of ~20 / min at the very most.
I think what I want is Delrin / acetal homopolymer. I thought I might get delrin tube and sleeve that over precision ground steel rod, or if that doesn't seem necessary then just delrin rod.
Would that be a good choice, or is there something more appropriate that you can buy for less than $25 / ft?
Or is this just a bad idea?

I have worked at Medtronic and at a contract to manufacture company. I have noticed the lack of well established suppliers for raw materials (metal products such as hypotubes, casings). There seems to be so few and we experience quality issues (dirt, corrosion) far too many times whenever materials are delivered. The lead times are also incredibly long.

Is it just me or have you experienced this?

I have been researching potential solutions for my low yield well, I have purchased a large water storage tank. I need to reduce the Gallons Per Minute of my well pump so it stops running the well dry by pumping too fast, and instead slowly and continuously fills the storage tank. I have read about the benefits of a VFD including soft start and variable power to my well pump, allowing me to throttle down the water production without having to pull the pump and install a flow restrictor valve. My only question is, how do I tell the VFD to cycle off or trigger a fault if it over-pumps the well? Currently, my pressure switch will turn the pump off if the pressure drops in the line as a result of a dry well. With this system, the well line will be routed directly into the storage tank, so there will be no pressure switch on this side of the tank. Any suggestions would be greatly appreciated. I am told I could install a float switch at the pump in the well, but I do not have the ability to pull my pump in the short term, save for an emergency.

Hi everyone, Lately I’m into a project that aims to create a sea floating buoy that you can connect to shore power with your vessel. This would require an underwater cable to the buoy. How feasible is this ? I can only find large underwater cabling project that connect continents or shore to oil platforms. Of course this is much bigger in scale, So I guess that means it’s not impossible. What protective mechanism would ensure the cable is secure and not exposed to fishing activities or anchors? Thank you for your help! Looking forward to read your opinions

I feel like I understand how the frequency of the vibration due to the piston movement follows the crankshaft speed. One period up/down of the piston happens every revolution, ok, fine..

Why is the frequency of vibration due to the connecting rod not the same? There are two components, up/down and side to side, and the period of both of those components completes in one revolution, so why isn't the total vibration frequency the same as revolutions/time? Why does a balance shaft need to go twice the crankshaft speed to balance the connecting rod?

This is hurting my brain and I think I'm missing some fundamentals.

Thanks!

For a product I make, I use thick hammered copper wire to create a structure. The wire is very thick. At first the wire is fairly bendable, but next I hammer the wire so that it is flattened slightly and much more stiff and perfect to work with. My question is , if I were to buy a heavy duty roller, that could roll/ squeeze/ press the wire to be the same thickness as it would be if I hammered it, would the rolled wire be as stiff as the hammered wire? Idk why but somehow I feel like it wouldn’t. But it would be much more ideal to quickly roll out wire as opposed to pounding wire all the time.

Hello! I'm currently working on a design that incorporates flexible locking tabs as the main feature and I am running FEA simulations on the tabs to ensure that they won't break during use. They are being made from a 20% glass filled polycarbonate with a 12,000 psi tensile strength and 700,000 psi tensile modulus.

All of my simulations are coming back with stresses well over the tensile strength (~30,000 psi) meaning that the part should be breaking. However, I have a machined sample from the same material that has passed all of the necessary flexure tests. I have looked over the simulation set up and conditions and nothing seems to be wrong so the only thing that I can think of is the material profile was created wrong. (Using Solidworks non-linear dynamic FEA)

Has anyone had success simulating a similar material? I'm assuming that the material is isotropic due to the shreading of the fibers as well as to simplify the simulation

(Normally this would not be a problem since the part is not breaking but I am planning on switching materials so I want to know if the other material will fail before purchasing materials/molds)

How can shredded PET or pellets be turned into sheets without first extruding them into threads?

I know they have to be melted and the usage of rollers to flatten them is involved, but how do you uniformly heat them into a single goopy mass that can be easily flattened while still hot?

I am interested into recycling PET and first I want to turn them into sheets. To then cut them into ribbons extrude them into threads.

I have looked at this all systems seem to involve funnels and them heating and extruding the melted plastic.

But I want to know how can you uniformly heat the pellets and extrude and immediately flatten them?

That is to say, how do you combine a heating element that also works as an extruder?

For making threads this sound easier since the pellets and the thread are thin enough that one can reasonably assume that all the plastic has an uniform temperature.

But if one uses pellets then there is the problem of the consistency of the thread varying due to the differences in size of different pellets, or if we are using grinded dust, then the problem might that not all the plastic gets melted and the thread has either varying thickness or comes apart due to not all the plastic fusing together.

One needs to very careful control the speed of the extrusion process to get un solid a consistently solid wire.

Using ribbons made from sheets has the advantage of making this way easier. Extrusion into threads becomes simpler.

But then we have the same problem as using dust, melting all plastic into a single big mass that can be flattened into a thin sheet has the problem of how to heat all the plastic at the same time?

You would need a massive heating element.

How can one solve this? How do you combine the extrusion and heating elements to make sure that

1. Heating is uniform

2. The heating and extrusion are fast enough that no blockages occur.

3. Complicated variable speed system to feed new materials are avoided?

4. The heating element must be close to the part that extrudes, but it seems to be very impractical to heat the extruder, way to costly to have such big heating element for making a sheet, even if that seems the easiest.

5. But a tiny heating element means that the material might become rigid before being extruded.

Hello all! I am starting a progression fantasy story about an engineer transported to a fantasy medieval world. I need your help! What sorts of things should he build, repair, and make? I also want him to kill monsters with home-alone-style traps. Let me know!!

Hello, I am a recent graduate that got a job for a really small company that designs and installs hydronic systems ( combi boilers) and LPG systems., mostly for small homes. Due to the size of the company things aren’t really done in an (engineering?ot scientific?) way, and there isn’t really any one to teach me there. So I am seeking some courses that go in depth on these systems, I do not mind paying.

Looking for the best book on general concepts of design but more in particular best practices on creating and enforcement of standards that can be applied to any type of engineering.

Idrk if this is the right place and just lmk where is the right place but im looking for a program that can simulate gearing kinda like Lego technic or the create mod for Minecraft or the game screwdrivers. If possible I wanna see like the torque and rpm and ratios but if not I’ll still check it out