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

I understand it's already a threat, but I mean if it gets to the point where it's an actual problem such as Manhattan going underwater, global drought, or the Yellow Stone volcano exploding. That type of ordeal. Do you think in the next century or shortly after, that we will have the means to terraform our planet back to 'perfect' conditions?

A Samsung Galaxy Tab A7 and a Polaroid PBT3005 speaker gets 3 meters. Is there a low cost way to get 5 meters?

Here are some pictures: https://imgur.com/a/arbArgd

The main beam contains some big splits and the smaller ones are all bending down between the wall and the main support beam on both sides.

I have been asked to review a calculation carried out by a third party to determe the force required to lift an object embedded in the seabed.

The calculation carried out is the submerged weight of the object + suction. Which makes sense. However they have calculated suction as equal to the submerged weight of the soil that has been dispaced by the embedded object, which makes no sense to me.

Wondering if this is some shortcut to account for soil failing before the suction is overcome or a away of shortcutting to an approximate answer?

Definitely not how I would do it anyway.

Hi all,

I’m working with my robotics team on upgrading an electric go-kart as an off-season project. We’re aiming for a 10:1 gear ratio to balance speed and torque, as recommended by the motor’s manufacturer.

Motor specs:

• Power: 5 kW
• Type: AC Induction
• Static Torque: 46 Nm
• RPM: 0–5875 (saw it exceed 10,000 RPM during no-load testing)

We’re constrained by time, so a multi-stage chain drive isn’t viable—we need to achieve this ratio with a single-stage chain drive.

My question is:
What is the smallest chain size (ANSI #40, #50, etc.) that I could safely use for this setup without risking failure?

Any advice on chain selection or other considerations (e.g., sprocket sizes, tensioning, durability) would be greatly appreciated!

Hello

I have a room that once heated to 20.50 degrees Celsius, loses heat at 1°c per 1.5hrs.

I'm tracking this info as I'm trying to improve insulation, so this is a "before" assessment. Is there a way to calculate the rate in R or U value or perhaps kWh such that I can compare improvements in this room, and then other rooms in a comparative way in future, but also allows me to assess if this is "good" or "bad"?

Or is it just a matter of saying 1.5°c per 90 mins, per approx size of 16sqm/40m³.

Thanks

I am CNC machining some rails for my onewheel. The mini mill I’m working on doesn't have a large enough x travel so l'm making it in 2 pieces. If I machine a large chamfer on the connecting faces will that help the weld depth and rigidity enough so that it won’t break? The way the onewheel hub connects to the rail is directly in the center, right where the seam is. Any ideas on how to make sure it's strong?

Say you have a mechanical component that is subjected to high temperatures (ie 2500K) Would it be best to:

1. Use copper cooling lines to provide water cooling, or simply wrap it in a heat shield, or both?

2. Make it out of something like 304 stainless that is stronger, lighter, and higher melting point, but lower thermal conductivity...or something like copper C110 that is weaker, heavier, lower melting point, but much higher thermal conductivity. Noting that the higher conductivity would give better heat transfer to cooling lines if they are used.

We need to safely pressure test a metal vessel so have conducted a hydrostatic pressure test. The plan was to fill the vessel with water, bleed any air out of the vessel so it only contains water. And then use a hydraulic accumulator with a nitrogen tank doing the work of pressurizing city water into the vessel. But we ran into an issue where the vessel stopped gaining pressure past ~450 psi (needed to go up to 1300). The gauge at the nitrogen tank would continue to climb, but we couldn't induce any further pressure on the vessel. The solution was just to bypass the accumulator and put the nitrogen directly into the vessel to achieve the pressure.

My question is, what is the math behind why the accumulator was refusing to induce more pressure on the vessel? I'm assuming that it had something to do with the large volume of water inside this vessel (talking about 19,000 cubic inches) and limitations of the accumulator (it was rated to 4000 psi w/ a volume of 0.95 liter). What math can I do to size the right accumulator that has enough stored energy for my future tests?

Hi everyone, I made a basic calculator for quick estimates. Before I spend more time on similar tools, I'd love to know if others find this kind of thing helpful.

Here's what it uses under the hood:

P_total = [Q × (f × (L/D) × (ρv²/2) + ρgh + K × (ρv²/2))] × (1/η) × SF

You can try it here: Fluid Suction Power Calculator | Engineering Tools

I know it's not comprehensive (no NPSH, no pump curves), but it's meant for quick initial estimates. Would love to hear:

• Is this actually useful to others?
• What obvious things am I missing?
• What other calculators would you find helpful?

If people find this kind of thing useful, I'd like to build more engineering calculators. Any feedback or suggestions would be really appreciated!

Basically, I'd love to design a Rankine or Brayton cycle as a small project, but I’m not sure how to approach the turbine design. I've already looked for books on my own, but haven't had much luck. Could anyone recommend some resources or guidance on designing turbines?

I'm a refrigeration apprentice, doing my schooling. I thought of this concept while studying. Looking for viability and proofing. My basic idea is if we could remove heat from the ocean to desalinate water. My concern is that it may require too much space before any effective cooling could occur. Or that it would have environmental pacts I'm not aware of. Beyond basic concept I would need help with proofing this as viable.

Refined Thermosyphon System: Design and Operational Summary

The thermosyphon system is a cutting-edge, scalable solution designed to extract excess heat from ocean water, generate freshwater, and contribute to climate change mitigation. Through innovative integration of renewable energy, sustainable materials, and advanced technologies, the system provides a multifaceted approach to address critical global challenges, including water scarcity, ocean warming, and environmental protection. Core Components and Functions

Central Thermosyphon Cylinder

    Heat Extraction:
    The vertical thermosyphon leverages the temperature gradient between warm surface water and cooler deep water. A working fluid (CO₂ or ammonia) absorbs heat from the ocean surface, causing the fluid to evaporate and rise through the system.

    Heat Rejection:
    The heated refrigerant flows to a heat rejection chamber, where it condenses within an insulated pool, transferring the extracted heat to the desalination process. The cooled fluid returns to repeat the cycle.

Insulated Pool with Integrated Desalination

    Evaporation:
    The insulated pool captures the rejected heat, creating a warm environment that maximizes evaporation. The system is insulated to reduce energy loss.

    Condensation:
    A transparent cover traps evaporated water vapor, which is directed toward inclined condensation panels. These panels cool the vapor, causing it to condense into fresh water.

    Freshwater Collection:
    Condensed freshwater is funneled into gravity-driven drip channels leading to storage tanks. A separate outlet for brine ensures salinity is managed effectively.

Concentric Structural Design for Stability and Efficiency

    Stability and Efficiency:
    The central thermosyphon is supported by radial horizontal arms, ensuring stability. Solar panels and flotation devices are arranged concentrically to optimize space for both energy collection and heat rejection.

    Energy Optimization:
    Solar panels provide auxiliary power, enhancing energy efficiency, and reducing reliance on external energy sources. They also serve as partial shading for the desalination pool, reducing evaporation losses.

Modular, Scalable, and Autonomous Operation

    Modular Pods:
    The system is designed with modular components, allowing for easy scalability to meet the needs of different regions. Pods can be connected or disconnected as required, offering flexibility for varying community sizes and environmental conditions.

    Autonomous Maintenance:
    Autonomous robots or drones can be deployed for cleaning, inspection, and maintenance, reducing human intervention and extending the system's lifespan.

Advanced Environmental Protection

    Double-Wall Heat Exchanger:
    The heat exchanger is designed with a double-wall construction, allowing any refrigerant leaks to safely vent to the atmosphere, preventing contamination of the water and the formation of carbonic acid.

    Eco-Friendly Coatings:
    Non-toxic, anti-fouling coatings are applied to all exposed surfaces to prevent biofouling and corrosion. These coatings are made from sustainable, bio-based materials that minimize environmental impact.

    Brine Management:
    Brine discharge is managed using advanced filtration or concentration techniques, reducing the environmental impact. In some cases, brine can be converted into valuable byproducts like salt or magnesium for industrial uses.

Energy Efficiency and Carbon Capture

Energy Storage and Hybrid Power Systems

    Battery Storage:
    Solar power is stored in batteries, ensuring continuous system operation during low sunlight or at night. This energy storage reduces the system's reliance on external power sources.

    Hybrid Power:
    Integration with wave energy converters or tidal turbines offers a consistent power supply, particularly in remote coastal areas, further increasing system efficiency.

Carbon Capture and Sequestration
    Carbon Capture Units:
    The system can be equipped with carbon capture technologies that extract CO₂ from the atmosphere or seawater, sequestering it in deep oceanic storage or in mineralized forms, contributing to climate change mitigation.

Phase Change Materials (PCMs):
    Thermal Energy Storage:
    The incorporation of PCMs within the system can store excess heat for later use, balancing fluctuations in energy demand and improving overall thermal efficiency.

Symbiosis with Marine Ecosystems

Artificial Reefs and Aquaculture Platforms

    Marine Habitat Creation:
    The flotation devices and structural components can function as artificial reefs, providing habitat for marine organisms. This promotes biodiversity and supports marine ecosystems.

    Aquaculture Integration:
    The system can be integrated with sustainable aquaculture practices, such as fish farming or seaweed cultivation, providing additional food sources while also helping maintain water quality.

Seaweed Farming for Carbon Sequestration
    Seaweed farms could be cultivated alongside the thermosyphon units, contributing to carbon sequestration while also supporting marine biodiversity and providing sustainable bio-products.

Eco-Friendly Designs for Marine Life
    The system employs acoustic dampeners and low-profile designs to reduce noise pollution and physical disturbance to marine species, ensuring the system operates harmoniously within its environment.

Outreach and Community Engagement

Public Awareness and Education
    An interactive dashboard can track system performance and environmental impact, offering transparency and educational opportunities for local communities, NGOs, and the general public.

Eco-Tourism Integration
    The system can incorporate eco-tourism elements, such as observation platforms or guided tours, generating additional revenue to support ongoing operations and increasing awareness of sustainable ocean technologies.

Collaborations with Governments and NGOs
    Partnerships with environmental organizations, local governments, and academic institutions can help further research, provide funding, and support system adoption in coastal regions.

Conclusion: A Scalable and Sustainable Solution

The refined thermosyphon system offers a self-sustaining, environmentally friendly solution for addressing global challenges such as water scarcity, ocean warming, and climate change. By integrating renewable energy, eco-friendly materials, modular design, and innovative cooling technologies, the system can be scaled to meet the specific needs of various regions while fostering symbiotic relationships with marine ecosystems. It represents a forward-thinking approach to sustainable freshwater production, climate adaptation, and ocean conservation, with the potential for broad adoption by coastal communities, governments, and environmental organizations.

Can someone point me in the right direction on how to determine if I need a thermal expansion loop in a natural gas pipeline bridge crossing?

Hi all,

It has been a while for me to do freebody diagrams and shear/bending diagrams.

I want to calculate the given sketch below which I have done with a calculator online.

Does anyone have good resources for me to do this? Or does someone care to explain it himself?

The beam is supported on 5 points and has a bit of overlength where a force is also applied.

https://imgur.com/a/NrHuvgK

What is the purpose of the thick hard film on the plasma TV display. UV filter or just anti-glare?

I have a charger with multiple usb ports. I wanted to charge my newly bought mini microphones. There's 2 wires given, one for each mic. I tested and the charging only works on this combination of multi-charger & wires given in some situations otherwise it won't work, and also affect other things like phone, not just the mics. (Phone ask me to check my connection, only when there's even any charging, so I assume wire itself is problem).

The most consistent way I can find is by charging through to the receiver (connect it to phone usb c port to receive the audio input. You can also charge phone while doing this by connecting this receiver to a charger cable) then pulls it off, then proceed to directly charge them like normal (although it will stop charging after a while). Is this some sort of usb wire quirk that I'm not aware of? Similar to how I found out 3 ways light switch can act weird without being completely unusable when they're broken.

I got so fixed on desalination I forgot there is plenty of water in the air. Is it practical to extract it. Say if you had a solar panel? would it be able to do auto irrigation technically speaking (budget aside)

Hello dear community,

As stated I would like some guidance on a project. I want to make an ultrasonic separator as seen in various papers like this one (https://pubs.aip.org/asa/poma/article/30/1/045004/819590) to use it for separation of algae from pond water. A friend of mine has a pond that has the tendency of growing algae that we want to efficiently get rid of without use of chemicals. Now I am an engineer but have no clue about electronics, so I don't know how piezoelectronic transducers work, what their limitations are in terms of penetration depth, how to procure them (it seems they only exist in the US and China but not in Europe), how you even power them or what controls are possible, as it seems that you only have one singular frequency you get them.

I would be very glad if anyone has time for some tips as I am stuck on this for a while now. I want to make progress on it although it is quite challenging. Also I would be glad if I get some reality checks because I don't trust ChatGPT on the matter. Thank you for your time!

Long story short: I'm in a one bedroom apartment on the 3rd floor of a 4 story, luxury apartment building. Im surrounded on all sides and floors by couples. One of these couples has sex so vigorously, they shake the whole building. They do it every few hours between 8pm-8am and I haven't slept through the night in months. There's no noise, it's just 10 minutes of being shaken like someone is running sprints on a treadmill or a washing machine is spinning violently off balance. Since I can't identify the source of the disturbance, the leasing office won't do anything. Id move if I could, but that's not an option. I have a heavy temperpedic adjustable base California king bed with foam mattress pads. Is there a practical way to add mass to the bed to stop the shaking? Is there a base i can place the bed on to absorb the shaking? Pneumatic springs?

I want a switch that I can send to a console and display a red/green LED to show if the equipment is on or off remotely. Does anyone know of a product like this or a possible solution?

I essentially want a central station, like an engine control room, at work to see possible problems and if the equipment is on or off. I want to do it as cheaply as possible, so no RSLogix or the like.

The skyrocketing cost of rent and mortgages got me to wonder what could be done on the supply side of the housing market to reduce prices. I'm aware that there are a lot of other non-engineering related factors that contribute to the ridiculous cost of housing (i.e zoning law restrictions and other legal regulations), but when you're designing and building a residential house, what do you find is the most commonly expensive component of the project? Labor, materials? If so, which ones specifically?

Most sources that I've found recommend values of 1.0-2.0D of thread engagement for bolted connections depending on the relative materials, but does this still apply for a bolt loaded purely in shear, where the strength of the joint comes from the bolt itself acting as a pin, rather than friction between the clamped surfaces?

My understanding is that as the preload on the bolt increases, there needs to be sufficient thread engagement to prevent the bolt and/or tapped threads from stripping. For a joint in pure shear, preload on the fastener only serves to retain the fastener and can be much lower so there's less of a concern about stripping the threads. Because of that, can less thread engagement be used, or am I missing something that still requires full thread engagement for these style of joints? I haven't been able to find many resources that cover this subject.

Hi, I’ve got this standing table from IKEA but it has to be manually moved up and down by using a rotating lever. Since the motion is clockwise for going up and anticlockwise for going down, I want a device that will automate this. I’m not familiar with engineering, so how can I go about completing this?

I’d prefer to build it personally over buying it. Any suggestions?

Table image: https://www.reddit.com/r/photos/comments/1gw3og1/ikea_standing_table_lever_for_raskengineers/

Video of how it works: https://www.ikea.com/pvid/1076998_fe001699.mp4 (0:05-0:12)

Hello everyone so I already have the gd&t standard and I do study it every so often. However I am looking for a book or website where there are practice problems that you can solve with solutions to said problems. Any recommendations would be wonderful 🤙

Hi ya'll I'm an EE needing some ideas for the mechanical side of things.
Appreciate any help even if it is just linking to somewhere I can educate myself more about this.

TlDR:
I have a part I have to make that requires lots of little opening doors, about 40, that needs to last a long time of opening and closing (~1.5 milllion cycles) at least 80 degrees, what are the most cost effective ways to make that? Inside office environment. Is it even feasible for under $30 USD? Production volume should be about 1,000 units, later 20,000. I know this likely means different production methods for each volume, so we can just focus on the large volume production methods.

More Detail:
I have a part I have to make that requires lots of little opening doors, about 40, that needs to last a long time of opening and closing, roughly I'd say at least 1.5 million cycles. The load is very minimal, basically just the weight of the 1.5" x 2" x 1/8" plastic door. It's not actually a door so you don't have to worry about the load someone will put on it with their hands it will be opened by a motor (potentially another linkage needed). The problem is making it not have ridiculous part count and lots of expensive assembly costs. You can visualize it pretty closing by just thinking of a plastic organizer but with a lot of little individual doors

https://postimg.cc/XXHdQnH2

It's necessary to the design that the door be able to open individually, and different times, and be opened and closed at least ~1.5 million times.

For a metal bushings and some plastic bushings this cycle life is no problem, but adding bearings and housings for the bearings to fit into and assembly is a lot of cost. So I've done a lot of reading about plastic bushings and plastic in plastic axles, and living hinges. I really would like to make it a compliant mechanism with living hinges but finding detailed design literature and particularly on cycle life prediction has been kinda hard, most just test up to a million cycles or far less. Does anyone have good reading on that? Maybe it's best to have plastic snap fit hinges like the product linked that can be part of the injection mold and housing, that would mean each door and it's hinge is only one part. But I'm not sure about estimating cycle life for that accurately either. I'd appreciate resources for that too, I'd be happy to pay for some books.

I'm also imagining a world where, since it's flat, I can make them all living hinges and injection mold one big part, each door with it's own living hinge all connected together, but I suspect given the strict flow requirements for polypropylene for a living hinge, doing like 40 hinges in one part with good results might not be feasible.

I'm leaning towards a snap fit male hinge built into the door, that gives one part per door, and the housing can have all female hinges on it so it would be 40 doors + 1 housing = 41 parts. Assembly cost can be cut if it's only 40 parts by making the user assemble themself. But I'm having trouble getting good resources on snap fit hinges cycle life. They can be lubricated.

I feel like there's some solutions I'm missing that I maybe just haven't seen yet? Or maybe I'm overestimating the cost of having a bunch of little plastic or metal bushings and hinges assembled in china? I do think if you could make it one injection molded part that would be far and above the best production cost, but who even makes living hinges that are attempting to go for more than a million cycles of life?

Thank you so much for any help, I've spent a lot of time researching and I'll spend a lot more, but I'm afraid I'll miss a "duh" solution that I've just not come across yet, or I'm already looking at it but I don't know because of lack of experience.

If you want to see the video, here it is. So the problem seems to be the rockets getting loose and taking it off course. How would you have fixed that? Wider wheels? Some kind of spring launcher? Prehistoric railgun?

We are planning a new Halloween decoration for next year that will be based on "Its the Great Pumpkin, Charlie Brown". The plan is to stencil some of the characters. The main bit is to have Snoopy's head rise out of the bushes every so often. Looking into ideas on how to make this work.

My mind went to a hydraulic piston. I don't know the first thing about setting something like that up though. The system would need to be able to function outside with the elements.

Hello everyone.

Is there any possibility, for a non-engineer, to build a button presser that presses a button at exactly 10 seconds? If yes, how would someone start this project?

Or are there any buyable ones anyone knows about?

Thanks in advance

Edit: I didnt expect to get that many helpful replies. So its theoretically possible, but practically near impossible. Thank you all for the replies, i definetly won the discussion with my friend

Hi all, I'm an ME undergrad working a co-op. I have to design a rig for testing a gasket, about a foot in diameter. I was told to make it very simple, with the gasket sandwiched between two plates and secured by bolts. The gasket thickeness acts as the walls. The cavity in the center of the gasket acts as the pressure chamber, pressurized to 500 psi.

I'm not sure how to calculate the thickness of the plates. Every equation I can think of has to do with the walls of a pressure chamber, not the ends. I feel like I'm overthinking this. Any advice? Thanks!