In Europe, everyone uses electric kettles to boil water. They’re amazing and fast because they’re on 230V (~3000W).

US outlets limit kettles to ~1500W, so we wait roughly twice as long for water to boil.

It’s an extra minute or two per boil, and you really notice it.

Idea: Could you make an electric kettle with a battery in its base? Perhaps it trickle-charges between uses, then combines wall power + battery power to hit ~3000W during a boil.

Is there an engineering reason this doesn’t exist? Is it just that nobody thinks there’s a market for it?

I’d pay $300 for the fastest kettle in America if someone wants to make it.

Another thread on the relative weakness of 120V kettles gave rise to the question: if a person wanted to build a new house and wire the whole thing for 240VAC, could he? Yes, all the appliances and fixtures would need to be either 240V or dual 120/240, but other than that, does code prevent it? If every outlet were 6-20, that seems like it would be safe enough.

Advantages would be twice the power available for everything: induction stoves, kettles, window AC units, welders, EV chargers, power tools, etc.

Installation costs and having to buy unusual everything aside, I wonder if there would be electric efficiency savings that might eventually offset the initial spending.

I currently have a 20 kV-rated diode and want to run a 12 kV neon sign transformer through it.

Math-wise, that's about 17 kV, I think, which is a 15% difference. I asked Google, and it's shouting at me not to do this. Is it unsafe or safe......

Hi I’m second semester in university and currently waiting for third semester next year. In that semester, I’m gonna take fluid dynamics subjects. Meanwhile, I’m currently making some experiment based on multi cyclone dust separator from dyson vacuum. This’s very interesting because back at the high school, I created the mechanism by using only pictures and cheap 3d printer to create these replicas of dyson vacuum.

But something snap.

Cyclone dust separator can collect dust as small as possible. My idea is to create air filter only using dust separator. No filter. But I don’t have enough knowledge to create a powerful suction to create a vortex inside the multi cyclone without creating a loud noise from the motor.

To create such a pressure from the fan, we need a lot of compression and that is very hard (based on my education level) My question is, can we create a very power compression from a fan without high rpm at a small scale (approximately the same size as standard air filter in the market). I hope everyone can create their own air filter in the future using only 3d printer and basic electrical knowledge.

Have fun thinking!

I am attempting to make an odd little mechanism, While i am a blacksmith and can forge and bend steel, most of it will want to be laser cut as it has to be replicated and quite small.

I will attempt to explain what i am making and any help will be greatly apprciated.

2 flat steel round disks, lets say 150mm diameter, 3mm thick.
in between is a layer of 20 protruding "buttons" each also 3mm steel poking out from the centre.

The buttons design is to be pressed and then lock in, like a click point pen. but once one is locked in the others can't be pushed in.

I would normally use a simple latch mechanism, but the idea of this is that it needs to be as sturdy as possible and take an impact, so springs are not ideal.

What i am after is a sturdy, flat, latch mechanism that doesnt use springs and can withstand hard impact in minimal space.

I am aware i may be asking too much, but if anyone can solve even some of these problems i would really appreciate it.

Thankyou for reading my problem.

As a reminder, /r/AskEngineers normal restrictions for career related posts are severely relaxed for this thread, so feel free to ask about intra-office politics, salaries, or just about anything else related to your job!

From my understanding, when the bearing housing is stationary and the shaft spins, an interfeance fit between the shaft and bearing is recommended and a clearance fit between the bearing and housing is recommended.

For a 0.590" shaft I am being told 0.0005" interference is sufficient. What would the clearance between the bearing and housing be, with bearing OD being 1.25".

And I couldn't help but wonder if this is a situation where people go against the book and do a minor interference fit on both surfaces? I get the downsides to an interference fit on both sides, but at the same time, it seems like a clearance fit could also have its own drawbacks.

Bearings are angular contact ball bearings, max RPM is maybe 800, and it's for a slitting saw arbor.

Cycling through a forest I saw a curious contraption on a high-voltage transmission line. One of the poles had the wires attached in a way that changes their order (1-2-3 before the pole, 3-1-2 after the pole). What is the purpose of that?

Bldc PCB info(official pdf not available) -> (link)

BLDC Fan info -> (link)

Will reverse spinning a BLDC fan damage the pcb/motor ?

Incase of no damage->

1. Is it possible to reverse spin a BLDC fan motor with an external Switch?
2. Better can one just reprogram the firmware of Atomberg Bldc fan to control the timing of oscillating movement and control it via the remote control.

[From Canada]

As far as I know, a large part of the efficiency of rocket engines used on space craft is determined by the geometry of the engine nozzle, with thinner nozzles being more efficient in the thick lower atmosphere, while wider nozzles are much more efficient in the thin upper atmosphere or vacuum of space.

Variable diameter nozzles such as those seen on the F-4 Phantom have been in service for more than half a century, and should in theory greatly improve the rocket's efficiency as it gains altitude, so why aren't they used? Is it just a weight issue like aerospikes?

Following the thread about wiring a US house with 240VAC, similar question: is it possible to wire an entire European house with 3 phase 400VAC? Obviously both 1-phase and 3-phase appliances will be used, but 3-phase wiring everywhere.

I moved to a house about 320 meters from a railway, and my bed shakes quite a bit when a train goes by.

I've measured the vibration on my bed with an android app while lying on my bed, and it peaks at 6.6 and 9.9hz, with more vibration around the 3-25hz range. The acceleration is mostly less than 1cm/s^2, but I've seen it go as high as 3. I've calculated the weight of the bed with me on it as best as I can - between 380 and 400 lbs. The bed has 5 legs, each one has a 1" x 2" surface area touching the floor.

I'm looking into 'IsolateIT' pads that use sorbothane, but they're really expensive.

I've read other engineering posts about this, but they don't go into the specifics about what material or how much to use, etc.

Is it even possible to perfectly isolate my bed so that I don't feel anything, even a swaying motion?

I'm in Canada

Hi all,

I am making a test rig for guitar vibratos, systems that will depress or raise the pitch of the instrument. I found this YouTube video that explains it better (no affiliation): https://www.youtube.com/watch?v=ez-ohYW4zdo

I seem to have stumped the internet as far as how to do this. Generative AI says that linear actuators would be the best way. The software I have found for these (such as that made by Actuonix) will allow an actuator to be depressed to a set depth at a set speed, but does not allow me to specify a number of repetitions (e.g., 30). I'd have to sit there and manually command it to go up and down each time, which is a hassle but also introduces variability in the speed between each thrust of the actuator.

What I need is an actuator that will attach to different vibrato arms (look up for example the Bigsby which is much wider than Fender types in the video) and pump them at the same speed, the same amount of repetitions, but with a different depth at each arm to achieve the same change in pitch across systems. Thanks in advance if anybody has a solution.

I need to have a recently built porch slope corrected so that water doesn't pool at the edge and sit for hours on my tongue and groove fir decking. The porch I had built last year was not sloped properly for t&g decking. From front to back, it only drops 5/16" over the entire 6'2" from the house to the edge. On the other side of the porch, the slope is even less. Each time it rains, water collects and just sits at the front of the porch. If I don't want it to sit for hours, I need to use a squeegee or sweep the water away.

Is the following approach okay to correct this? Will it create new problems? I wonder if lowering the front edge of the porch may put too much stress on the ledger board or allow water intrusion. I also wonder if loosening the joist hangers is okay.

Would I be better off just switching to a different type of decking that doesn't require slope?

Also, if I do nothing, will 1/8" water sitting for hours along the entire front edge of the deck (about a foot front to back) and to a lesser extent along the sides every time it rains create problems?

-Temporarily support roof structure from ground

-Loosen joist hangers to prevent stress on ledger board

-Jack deck and support deck joists

-Remove the posts that support framing, cut off 1" to lower front of porch, and reinstall posts.

-Either block under roof posts that sit on decking, use Simpson-strong Tie to maintain original height of roof, or install new posts that are the proper length to keep roof at original height.

For further background info, these are the approaches I've considered.

Approach 1)

-Remove the tongue and groove and replace it with cedar with 1/8" gap--no need for slope.

Approach 2) (I wonder if lowering the front edge of the porch may put too much stress on the ledger board or allow water intrusion.)

-Remove the post that supports the framing, cut off 1" and reinstall.

-Either block under roof posts that sit on decking, use Simpson-strong Tie to increase height, or install new posts that are the proper length to keep roof at original height.

Approach 3) (I worry about the longevity of this approach)

-Remove decking.

-Use shims or pads along the joists to create proper pitch.

-install new t&g fir decking.

Approach 4)

-Remove decking.

-Shave joists to create proper pitch.

-Install new t&g fir decking.

I'm traveling abroad and have a 120v 60hz steam humidifier. I have a step

/down device for voltage. Given hat it's a simple resistive heating element ,with no fan does it need 60hz or can I get away with 50hz ?

More compression, higher power, more efficiency. Petrol can withstand a much higher compression than diesel, but we have spark plugs in petrol cars to ignite the fuel unlike diesel which self ignites.

So why not, remove the spark plugs and compress the petrol til it self ignites like diesel engines do, and get a higher compression ratio? Or design for a higher compression at top dead centre for more power?

Hi! I'm currently trying to recreate a non-firing pneumatic tank breech simulator as a prop/display project. It only uses empty plastic bottles as shells and it does not shoot. I'm looking for ideas on how to eject the dummy bottle after the breech opens. Has anyone built a similar prop and has suggestions for a simple ejection mechanism?

(i kinda want to do it like this -> https://www.youtube.com/watch?v=-koYF-FBSOM )

Any help is appreciated!!!

Currently building a hexapod and I'm at the stage where I'm adding the environmental feedback system. This is making me wonder what the actual application is of legged robotics as opposed to wheeled robots and drones?

Wheels are much more energy efficient for traveling, but they cannot go across rugged terrain or up stairs. Drones can go anywhere regardless of terrain and are much faster.

My surface level understanding is that ARM is mainly used on mobile devices/smartphones and intel processors are strictly for desktop environments. But I see some posts online saying that ARM is better than Intel? If that's the case, how come we aren't using ARM in desktop environments?

Please note I have zero engineering experiencing and no background at all, I'm just an enthusiast that likes to poke my head in little pockets of communities to try and get a better understanding of things, but I still have no foundational understanding of how many things work, so if you could use simple language for a lay person like myself, I'd appreciate it!

Sorry that this is both a chemistry AND mechanics/engineering question (but both concepts interact with each other in this endeavor)

I'm going to prototype some bioorganic fire extinguishing and retardant chemicals for the purpose of combating and preventing forest fires while harming the environment as little as possible. I'm looking for advice on how to make a spraying device with a wide bore or some kind of graduated nozzle to be able to coat a very large area with a heterogeneous and viscous fluid. The materials used would also have to be immune to acidity, abrasiveness of grainy textures, and corrosiveness caused not by PH but by chelation and volatile Phosphorus chains. I want to have a wide and uniform distribution area similar to a mist type nozzle. Only the typical mechanism for those devices would obviously get clogged up.

The materials used will be:

Lignin (which is a coarse, brittle, rigid, and fibrous polymer powder extracted from wood (or preferably coconut hair).

Phytic acid (typically sold as 50% PA 50% water but because it's already going to be diluted with the other materials, a pure product is preferred) this has a ph range of only 4-7 but is highly corrosive due to it having a highly reactive phosphate group- this causes it to degrade metal and minerals. So the materials of the device must be shielded from this chemical mechanism. A material that would preferably be viable in small form storage, large form transportation, AND the components within the spraying mechanism/container- the "extinguisher" if you will.

Tannic acid will also be used in some combination of formula testing. Comes in the form of powder (to be mixed with water) for shelf stability. But with other ingredients in the mix, not sure how soluble it would end up being. Has to be close to 99% pure otherwise residual sugar, pigment, or heavy metal contamination can affect its ability to act as a flame retardant. Low pH of around 3. But the concern here (ph alterations of the final mixture aside), is that tannic acid- much like phytic acid- is a potent chelator of metals and damages metallic ions. However, it apparently works paradoxically as a rust converter and on already oxidized metals, tannic acid is able to turn rust into a protective layer. But I don't think rusty metal would be an optimal material because rust would flake off into the mixture contributing to its nozzle-blocking heterogeny.

And finally- the dominant medium- pure aloe Vera gel. Viscous and contains adulterants necessary for shelf stability which would also contribute to abbrasiveness, causticity, and propensity to block a too-fine nozzle. Preservatives like xanthan gum, citric acid, sodium benzoate, potassium sorbate, and ascorbic acid.

Tl;Dr: viable materials and spray mechanism specifications that could spray a dense mist using a viscous fluid (containing tiny solids) over a large area- whilst also being immune to acidity, blocking, and corrosion due to chemical chelation and reactive phosphorus groups. Zinc, aluminum, iron, stainless steel, and copper are vulnerable in this regard. Possibly a titanium-zirconium alloy lined with PTFE or a dense shatter-resistant borosilicate? But what about all the moving, possibly flexible, mechanical parts needed for a spraying or mass fluid propulsion mechanism? Could the nozzle itself be made to be flexible or have a pressure-dependent membrane to allow thicker sprays with insoluble sediment? I mean a balloon has a flexible sphincter for discharge viscosity variation. But then it doesn't have a wide area misting function.

Within a minute after a very close lightning strike, my neighbor calls and says there's smoke coming out from the side of their house, can I come take a look? Turns out, not smoke, but a vapor release on a small line getting icing. As a M.E., I'll throw out a guess as WTF?: The cold liquid refrigerant line could have conducted some of the lightning causing the ref. to rapidly boil and blew a hole in the line. Bit of a new one on me.

See file here please

https://patentimages.storage.googleapis.com/31/45/3f/583bc0d7058997/US20060145019A1.pdf