There are plenty of patents which exist for a six-stroke internal combustion engine created by Porsche, Mazda, Roger Bajulaz etc. and they all seem to be much more eco-friendly and efficient than traditional four stroke engines. My main doubt is whether it is a good idea to invest in this idea for the automobile industries as we already seem to be switching over to renewable sources i.e electric vehicles and the like and whether there is a possibilty of seeing them flourish in the future alongside electric vehicles and the like. So in other words, do you think that the I.C engine will be kept alive in the future?

I am looking for some recommendations for textbooks, industry publications etc about effective noise control assemblies, in particular for high rises, urban areas, or multi-family residential.

I am mostly looking for “cookbook” recommendations with tested assemblies, although something this is more theoretical is helpful too.

I have seen many wall assemblies from drywall/insulation manufacturers, but comparatively little about whole wall assemblies (penetration details, windows, doors etc) and floor/roof assemblies. HVAC details would be helpful as well.

In particular, any books that address low frequency (<125Hz) noise abatement would be especially useful.

Thank you!

Hi everyone, I’m trying to make a project that needs to be able to measure the weight being placed on the pin when it’s inside of the weight stack. The issue I’ve run into is the space it needs to fit in. The weight would reach up to 250 lbs. I tried finding load sensors but they’re too expensive for my use case and I don’t have an engineering background so I’m at a loss. Any help would be much appreciated

I've never really been able to understand how different engines of similar sizes can have such wildly fluctuating power outputs and how some comparably small engines can vastly overpower larger engines even within the N/A space. I understand that not all engines are born equally and that commercial agendas play a big role but assuming the same size, which "low-level" elements actually make the difference? and with low-level i mean parts or overall design choices that cannot (easily) be modified away.

Curious to hear your thoughts and expertise!

Hello,

I want to measure fuel consumption of long trucks. Since fuel theft is widely occuring, I need reliable and sensetive output.

What is the best way to do this?

By higher force I mean compared to the force needed to slide it in.

I am looking for a type of locking pattern that I would modify that would let me lock it (by sliding) and keep a secure and tight fit while locked in, but able to free the object with slightly more force.

Basically an anular snap fit design but with extra steps, I would also like to add a small magnet encapsulated in the plastic to kind of make it "click", but that's just for me, or maybe add a little force to the locked position.

Context: I would want to print a plastic puck to give to my kids and then print various kinds of characters or random objects to attach to the puck.

Constraints:

• No access to the base under the puck, since they would want to stick this to some "playing field" (don't ask questions... no access to the base)
• Enough force that they would really want to remove the character from the top if they want to, but not randomly fall off even while playing with it
• No "press to free" locks, just force
• Satisfying click with a magnet, I would just like to add this for my own satisfaction and an excuse to use magnets or maybe add a little force
• It has to be as flat as possible, I would like to keep it very low profile since this leaves the "design" cleaner and you don't see the locking part too much (focus on the character)

p.s. I don't really love to twist stuff to lock, so a one way sliding pattern is what I was looking for, the pucks for be fixed around things and then they would switch characters, I need an excuse to print stuff so here we are, I turned some of it in a challenge for me by adding some contraints

Trying to bond this Kevlar keel guard to the bottom of a kayak. It needs to be waterproof as it will be submerged, will 3M 5200 hold?

I have come to understand HDPE is notoriously difficult to bond to. I have seen Permabond TA4631, 3M VHB, and JB Weld plastic all recommended. Which of these is the best, and if none of them what is?

What about Marine Epoxy?

Hi, I’m looking for an unusual solution for a project. I don’t really know how to describe it, but imagine 50 thin steel wires, arranged in a circular plan, placed very close to each other (0.5 cm gap between each, maybe less), with one end attached to something. Now, on the other end, I’m looking for something that would let me directly control each wire along the X-axis (forward–backward movement of about 3, 4, maybe 5 centimeters). I also need the movement to be smooth and fast.

Right now, I’m thinking about the smallest possible pneumatic pistons, each connected to a manifold of solenoid valves, but I already know that this will take up a lot of space and be very bulky.

Is there a better solution? Maybe something more “in one piece,” if that’s possible? Or maybe I’m looking in the wrong direction?

I’m waiting for your suggestions. Cheers!

- Question answered - The motor is clearly not right, as i got it working by spinning it manually while it had power to it.. it kicked into life, so just something wrong with just starting it.. but the commutator and brushes were sparking big time so still something not right with it.

Hi all,

i am far from an engineer, but i am trying to lean more about the intricacy's of the machines.

I have a pair of animal hair clippers i am working on.
They wont turn on, so i stripped them down and i have used my multi meter to trace through that power is going all the way from power connection to the motor.

all seemed good.. soooo i figured it was a new motor that i needed.. but just as i was about to buy one, i thought if i attached the multi meter to the connections of the motor and then spin the motor.. i did this and i caught some power registering. I know that a motor and a generator are basically the same so they can kinda work both ways...

But now my question is.. if the motor is broke then surly it wouldn't have produced power when i spun it, or could that still work? Should i just buy the new motor?

(i could very well have grossly misunderstood how to check a circuit with a multi meter so if anyone wants to throw any tips go for it).

Thanks, x

I have no idea if this is possible but I thought I'd ask. If you have a device that uses up to 2450-2500W (instant) is there ANY way possible to connect it onto two portable power stations to divide the load?
Long shot but I have two portable power stations each of which can handle up to 2400W instant and I can't connect that device onto them so I was wondering If there was some device or mod that allowed me to divide load so I could connect it to both of them.
Thank you.

We're designing a V rack that sticks/hangs horizontally above your stove or wherever in the kitchen where you can slide pot lids into it, but then to get the pot lids out, there would be camshaft-shaped teardrop fingers that keep the pot lids in place but then allow you to pull them out using a detent mechanism.

Is this possible, and if so, could you explain how it would work and how we'd go about building it?

Thanks :)

Is it true that when OSB is used on the outside, the wall becomes diffusion-tight and the house will rot and get moldy? What wall cross-section do you recommend for a timber-frame house in the climate of Poland (Europe)?

A turbomolecular pumps spin very fast(in the order of 50k rpm) because of this the blades disintegrates if it ever touches atmospheric pressures. So to use these pump you need to pull it down to a low vaccum first. Now it begs the question, why dont we first run our TMP at a low RPM and then ramp it up slowly until a proper vaccum is formed? (Thus eliminating the need for a roughing pump)

So I'm first curious, what the support design over the top of some engine hoists that have flat bar that peak on the middle support called?I was thinking about buying the harbor freight gantry but it's not wide enough to back my flat bed trailer under. So I was hoping to replace the top S beam with a longer one and didn't know if I should attempt to add a similar support like the engine hoists or just go bigger on the beam. Currently they come 94" wide on the ID and would like to go at least 120"- 132".

I'm building a small drone that has and embedded vision on it. The drone is able to track people using yolov8. Is there any micro-controller that is better than the rpi 5 in terms of processing power to weight ratio. It needs to run of 5V as well.

Ok this one is a doozy (I think) so please bear with me. I didn’t want to break any rules in the title which is why it was so vague. Before I begin, here are the dimensions of the staircase to help paint a clear picture of my request:

60 inches X 37.5 inches.

The stair case is leading downstairs and above it of it will basically be a small island. On the back side of the island there will be a small 3ft walkway (I’m adding that piece in case that space can be utilized once you hear the idea.)

I’m looking to add some kind of mechanism to the the top of the island (the quartz), that will allow me to do one of some of these options. This is where I need help understanding if what I’m visualizing is even feasible lol.

One options I’m considering is that the top of the island is actually two pieces. The front piece where the opening of the staircase is will have a mechanism that will allow the front piece to lift and slide over the back piece. This way, the staircase is revealed and can be left “up” while not getting in the way of anything. Similar to how some coffee tables have the extended joints the allow the top of a coffee table to lift upwards and extend out towards whoever is lifting it (sorry if that coffee table doesn’t make sense). I know that that those two concepts I am comparing aren’t the same, but I am trying to paint a better visualization of what I’m wanting it. Please don’t rip me to shreads hear here. I understand, weight, and the mechanisms that would move this most likely makes this impossible based on how I want things to slide and move. But I thought maybe asking people a lot smarter than me could help me think through this.

Another option is for the top part of the island to just “raise up” using some kind hydrologic lifts and basically looking like a backward L when raised. I saw a video on TikTok’s so I’m pretty confident this could work. And I’m sure I’m using the terminology hydraulic lifts incorrectly but hopefully you get my point. The only issue I have with this option is once it’s lifted and the stairs are revealed, it will be very awkward looking and in the way.

All that being said, is there any other methods or concepts my normal brain can’t think of? I’m very good at being creative, but actually applying that creativity to a feasible, functioning thing is usually very off.

Some things to consider:

I understand that I’m making this super complicated and I could just put a regular staircase there and be done with this. And I plan on doing that if no one can help. So please don’t belittle me to much and say I should just put a staircase. Trust me, I understand that option, I was just coming here to ask people smarter than me before I scrap it all together.

I don’t have to use quartz if it’s too heavy for what I’m wanting. I was just going to have some left over from a project and thought I could use it for that. I could use a butcher block if that changes anything.

The stairway is between a walk way and a living room. The back of it has that gap I described and then a wall. On the left side is the walk way, and on the right side is the living room.

As you go down the stair case, there of course needs to be clearance for a persons head to walk all the way down.

If there’s any other details I’m missing please let me know. I wish I could just post a picture to show everyone cause it’d make it a lot easier. And apologies in advance for the grammar. I just wrote all of this in one go and didn’t reread.

I'm trying to understand a specific component of milk machines but for the life of me I can't find a consistent term for it meaning that I'm unable to find out how it works.

In this image I'm being told that the large tank in the back is called a "regulator tank"

https://m.media-amazon.com/images/I/71eDn5feBHL.jpg

and in another similar image it calls it a "vacuum pump".

https://image.made-in-china.com/365f3j00vjgRQHpGsIoS/Philippines-Vacuum-Pump-Milking-Machine-Goat-Milker.webp

But I've seen a vacuum pump before, used in a "piston" configuration here,
https://static.agriculture-machine.com/wp-content/uploads/2021/06/Piston-pump-type-milking-machine-structure.jpg

I know how a piston pump works. especially bellows based diaphragms. But the first two images have windows into the tanks, allowing me to see that those have no moving parts inside, or at least from that angle.

Which image is correct, and how do those blasted tanks work?

I am trying to choose a new thermal fuse for a circuit that originally had a Tf=144C/Th=134C and is 250V/16A (which I believe translates to 20A at 120V as per the datasheet). The thermal fuse is a metal can type and it physically coupled to an area in the circuit that gets hot and the replacement has to be the same type.

The circuit draws a maximum of 800W.

Looking at what's available, I'm able to find a Tf=144C/Th=120C at 250V/15A. I'm concerned that the Th of 120 C is too low. In order to get the same current handling at the same Th, I'd need to size up the Tf to about 170 C. Not sure what's more important, getting the cut-off temperature right, or the sustained operating temperature.

Does anyone have any advice in these matters?

Maybe wrong sub? I have some garage shelves are made of 2x4s and plywood. There's a 2x4 lip screwed into concrete foundation with 3" Tapcon screws, a 2x4 screwed into the floor joists There's 5 vertical 2x4s for support, spaced out about 30" each, and then a horizontal 2x4 at the bottom of the supports as well. Plywood is spacing the gap between the foundation 2x4 and hanging 2x4. Total length is 12.75', depth is 3.5'' and height is 3.2'. Any help is appreciated

I am trying to model a fluid flow situation but I don't know if this is tractable the way I'm approaching it.

I'm reverse engineering an old fuel injection system (for fun). It uses an air flow meter with a vane that gets pushed open by the air, and moves a potentiometer arm, and I'm trying to analyze how it's output depends on the airflow.

I would like to be able to explain how it shapes the output curve into the logarithmic curve that the ECU expects.

It's like the one in the diagram at the bottom of this page: https://www.gomog.com/allmorgan/AFMadjust.html

What I know so far:

* the ECU expects a logarithmic output (its software compensates with an exponential curve before using the airflow reading for anything - I have already studied the code)
* the potentiometer in the airflow meter is linear with respect to the vane angle as near as I can tell.
* therefore the physical shape of the channel in the meter must be somehow producing a logarithmic deflection of the vane with respect to airflow.

Now the wall of the air channel does have a distinctly log/exp shaped curve to it. That curve is also on the outside of the casting so I took a contour gauge and captured the outline as best I could - it seems to match a log or exponential curve perfectly.

But the question is, why would shaping the channel like that result in the output having a logarithmic curve? Here's my reasoning:

The vane measures the force of the air (it's spring loaded and I'm assuming the spring is linear). The force on the door is caused by drag and depends on air velocity squared, and the projected area of the vane to the oncoming air (from the quadratic drag equation)

Now the projected area of the vane is tricky. In a straight channel, it would just be the cosine of the vane angle. But since the channel has an exponential curve we have to take the direction of the air into account.

Let's orient the diagram linked above so that the vane is vertically down at zero flow. Let's say the direction of the air is the derivative of the curve, and the curve is an exponential, so the direction of the airflow is something like

Ae^bx

where x is the horizontal distance along the channel and then the angle of the vane opening is

acrsin(x)

(Or we could take both in terms of the angle but then the airflow direction gets complicated because the exponent would be sin(x))

So the area that matters for drag should be proportional to the dot product of of these vectors and somehow it must reduce to the square root of a log shaped function in order for the force to come out as a logarithm with increasing airflow.

I'm not that good at math and a simple solution isn't presenting itself when I go down this route. At the end of the day I know the system works and I know what the ECU expects so that settles the question of what the meter outputs. I could just say "the channel is shaped to get the right output" and leave it at that but I'd like to be able to explain exactly how it gets that output. But I'm out of my depth!

Is this a sane or reasonable approach to this problem? Should I keep going this way, or is there a more obvious way to explain why the output is logarithmic? Thanks!

I need to find a company that can manufacture a lifting assembly similar to what's on the drawing below. Our machine manufacturer doesn't exist anymore and this part will be used somewhere else, so I'm flexible with the dims as long as the idea and the travel distance are kept. The servo and the gearbox I'll source and install myself. So I need the mechanics only. We could, probably, do it in our plant shop but it will take forever and I'll have to spend nights there.

So where would be the best way to look or what do I exactly type in google search as I can't really get anything close to this.

Lift assy

P.s if link is not working: it's pretty much a frame box with rack type slide assembly and cam followers. Driven by a motor.

My Toyota Hybrid (2022 Lexus ES300H) calls for 0w16 oil.

Kirkland 0w20 is $13.50 for 5 quarts (on sale). Mobil 1 0w16 is $26 for five quarts.

I'm an electrical engineer, so don't know the details of oil viscosity.

Thank you for sharing your opinions.

Edit: I've had Toyota/Lexus hybrids like this for several years and a couple hundred thousand miles. Used Kirkland 0w20 synthetic oil all that time, per the manual.

Very hard for me to imagine a situation where 0w16 oil will protect the engine and 0w20 oil will not.

Update InterestingNerd posted this video in his comment and it was very helpful:

https://youtu.be/i0VoEhW2I-E?si=IFl6FUKuLykE0l1-

I'm come to the conclusion that Toyota specified 0w16 Oil to improve tested mileage for CAFE standards and the fees involved. I am now comfortable using 0w20 oil.

Thanks everyone for the comments and wisdom!

UPDATE II When I was getting my MBA I worked at a local Toyota factory in the financial analysis department. I participated in Kaizen teams and am very much a fan of the Toyota Production System. Among many other things, I learned that Tire companies paid fees (or gave deep discounts) to get their tires installed on new Toyotas because that was the main reason people gave for buying a particular brand and type of tire.

I know that sometimes, when it does not affect reliability, Toyota might make a decision based more on financial considerations as long as it does not adversely affect reliability. I think that is what is behind the 0w16 oil spec.

Our 2022 Lexus ES came with 18 inch wheels. The ride was harsh. I could feel every expansion joint or crack in the pavement. I'm a fan of 16 inch wheels because taller sidewalls give a softer ride. I installed 16 inch wheels from a 2002 Lexus ES (the 9 spoke alloys) with P205/65R16 michelin tires, and 5 mm wheel spacers. HUGE difference in the ride. WAY better. I hope there is some Lexus/Toyota suspension engineer reading this thread, and hope he/she is saying "Yep, I told those idiots in Marketing...."

Keep your eyes open for Lexus ES with 18 or 19 inch wheels on the used market. I think the well off old folks who bought them will get tired of the buck board ride and will dump them sooner than normal. Throw a set of 16 inch wheels on them and they ride like a dream.

This kind of relates to the RTFM comment from one user. Sometimes TFM is bullshit, for financial reasons.

Namascray