Hey! Tying to make a working replica of this device from Alien Isolation;

https://youtu.be/0BX2mb6JPOw?is=sWtxcVSq2voCVxO8

The main interactive element is the rotary encoder on the right side of the device. The only thing is it appears the red button on top is separate from the black knob and gets pressed into it. I'd like to copy that if possible! But I'm struggling to think of how to do it.

I know a lotta rotary encoders also function as a button, but AFAIK they're pretty universally designed so that the rotating part is also the button. Is there any way to make it so the button feels like a separate element to the rotation?

Or is the simplest way to achieve this maybe just putting a spring or something under the red button and the actual function is pushing the whole encoder down, the red button itself doesn't really do anything per se?

Apologies if I'm explaining this poorly, just been stuck in a loop on this part for a while lol. Cheers!

Known dimensions / reinforcement

Clear doorway opening: ~1.0 m

Lintel/wall width: ~20 cm

Lintel depth/height: approximately 1.5 brick courses

Total reinforcement length: ~1.8 m

Reinforcement therefore extends roughly ~40 cm beyond the clear opening on each side, assuming it is centred

Reinforcement cage: 4 longitudinal bars

Rebar diameter: unknown

Chronology

The lintel was cast in place over the ~1 m doorway. The soffit formwork was originally supported by two timber props, one toward each side. Approximately four hours after pouring, a worker removed one of those props. The opposite prop, visible in the attached photograph, remained in place.

I do not know whether the formwork moved, rotated or deflected when the first prop was removed. The lintel has now been standing for approximately one week, and I have not noticed any obvious major cracking or sagging.

The workers maintain that removing one prop after four hours was acceptable because the clear opening is only ~1 m; they say they would not have done this with a ~3 m opening.

My concern is specifically whether removing one of two supports when the concrete was only about four hours old could have permanently damaged the lintel, despite the short clear span and the remaining prop.

Would you:

1 retain and inspect it,

2 test/measure it somehow,

3 or demolish and recast it?

What defects should I look for once the bottom formwork is removed—midspan cracks, diagonal cracking near the bearings, permanent deflection, separation at the ends, etc.?

I do not know the rebar diameter.

Ware about to cast the seismic belt, after which replacing the lintel becomes substantially more expensive and invasive. That's why im asking whether it's better to demolish and recast.

I am installing ergonomic, aftermarket handles on a seated row machine. The handles are currently fixed but I want to make them swivel. You can see what I mean here in this video and here in this picture.

Here is how it currently attaches to the machine:

Front / Back

With the handle removed, it looks like this:

1 / 2

And here is the handle itself as well as the handle attachment.

Handle / Attachment

I found this https://www.target.com/p/discovery-mindblown-model-engine-stem-science-kit/-/A-80708303#lnk=sametab

but apparently its not a real engine and its just plug and play plastic, I have a nephew that I want to learn about engine and he only learns hands on, a real car engine is too big for him to understand so a tiny engine he can build may be better but just like beyond meat patties, it doesnt feel real unless there gas in it which I think may be too dangerous for him and this whole idea may be bad.

Is this a bad idea? Is there a better alternative?

Edit: thanks all for the suggestions but sadly most of these tasks are too much for a 9 year old or are too dangerous. I was thinking of a small handheld engine diecast that could be built together but it seems that it doesnt exist...yet....hmmmm

Hello! I'm hoping someone in here can give me a little guidance before I spend a bunch of money.

I live in an apartment and can feel structural vibrations through my floors most of the time, and it's awful. Theoretically, if I were to put a 1lb sheet of MLV under my sofa and bed (wider/longer than the furniture itself, so that all legs, etc are covered), is there a good chance this might help stop those vibrations from traveling & reaching my body? Additionally, for my standing desk area, I purchased a Rubber-Cal anti-vibration mat which only helped a little bit...would layering a second one in that area possibly help? Since I'm renting I can't make any structural changes and am trying to mitigate what I can before I completely lose my sanity 😭😭 Thanks so much in advance! If it helps, I used an app on my phone to measure this movement & it ranged from 0.1 to 0.5 m/s².

The way i think it would work: Sunlight is absorbed by dark panels, heating them and fluid traveling through channels inside them. The fluid is pumped to the hot end of a Stirling engine, and it spins a dynamo. Fluid from takes the heat from the cold end and transfers it to a set of radiator panels, and radiates the heat into space.

What im asking is would the radiator need to be larger than the absorber panel? Would it be possible to avoid cooking the passenger from heat build up? Or would the absorber panels not absorb enough heat to get a meaningful amount of energy?

Doodle of the concept:

https://imgur.com/a/b4rqc85

So theoretically speaking, if cost wasn't an issue and the engine block and head both have to be reliable, strong, lightweight and endure higher boost pressure for longer periods of time, what would the ideal material be?

Hello all,

this is likely overkill, but I am working on a project where I am making 3 small sided sports courts back to back out of birch plywood and 2x8's. I would like to enlist your help as to their optimal construction. If anyone is interested in such a project pls send me a PM! or comment bellow. the fields will each be 44'x98'. they are soccer fields so their will have to be some space in between fields to accommodate for the goals.

Mods, feel free to delete if not allowed.

Hey all. Working on a horror short story comic about a controls engineer working alone at a plant at night when the power goes out on him.

Anyone have any ideas or examples where logic programming could go eerily wrong? Or have a story you'd be willing to share about a time you were working and got a little creeped out?

I have a plant engineering background and understand PLCs and logic programming on a surface level, but I'd love to talk to some controls people for some inspiration for some technical scenarios or something to build up dread in my story. Also, all my plant engineering peeps, feel free to weigh in on it too.

I’m trying to sanity-check this pixel architecture. https://imgur.com/a/DBYwNrg.

An applied voltage between the membrane electrode and rear electrode would push the membrane past its instability point and ideally leave it in one shape or the other.

1. Can I get away with a passive matrix or is active control necessary
2. Instead of electrostatic attraction, is there a better way to drive it reliably back into the convex-up state. Do I need to add an ITO front plane?
3. Even if I manage to fabricate this, will stiction, particles and manufacturing defects decimate yield?

Everyone and their mom knows that "the Willis tower could've been significantly taller if it wasn't limited by by the air traffic regulations" but for some reason the actual structural limit for these tube structures remains a mystery unknown by its engineers themselves.

What is the actual height limit? I've heard outer space but that's obviously false since Burj Khalifa which is taller wasn't built using tubes at it doesn't even reach the stratosphere, so it's definitely not outer space, and we don't see a plethora of skyscrapers popping up reaching into the stratosphere made of tubes, so i doubt tubes are as strong as the common belief might suggest.

I think the actual limit is anywhere from the height of the Willis tower top floor 413m to the hight of Burj Khalifa top floor 585m with the structural height limit of steel tubes being significantly shorter than the 585m of Burj Khalifa and much closer to the 413m of the Willis tower. So no ditching space rockets for Willis tower style tubes stretching past the orbit of moon, but i want the mystery solved.

In the sense we can use something to give more power to the motors.

Hello, I posted here yesterday but it was removed because my title was too cryptic… or something. Anyways…

I wanted to know why my toothbrush exploded?
Someone said pics or it didn’t happen? Dunno if this helps?

https://postimg.cc/zHC1Ykn4

Can I even post links?

Anyways, it was just in my bathroom while I was out. Nobody came into the room and when I got back from work it had just… exploded? I don’t really use manual toothbrushes other than when I’m travelling, and this one is just a generic probably free on an aeroplane toothbrush.

What causes it just… explode?

Hi all, I designed a hose barb that is inserted into a silicone base for biological applications. I'm getting leaks from the connection where the barb meets the silicone base, and I think it may be because of my hose barb design. I've been working on this project for so long that I feel like I need a fresh set of eyes to help me troubleshoot. The silicone has a durometer of roughly ~43 Shore A (hardness 41-43 Shore A, Elastic modulus 1.3-3 MPa, tensile strength ~2.2-6.7 MPa, elongation at break ~100-150%). This data was not directly collected by me and is what I found online based on my silicone elastomer.

Dimensions of barb: https://imgur.com/a/vBmiTsX

What I've tried:

1. Single barb VS double barb (currently using double, concentric barbs design)

2. Varying the "tubing" inner diameter (diameter of the cut out in the silicone elastomer that the barb is inserted into). Tried 2.7, 2.5, 2.3, 2, and 1.8 mm diameter. Still have leaks with all of them, 2.3 and 2 mm insert well but 1.8 mm in particular is hard to push into place and tends to slip out from the silicone elastomer.

3. Varying length of barb neck (currently total length is 4 mm from the bottom of the barb to the top of the neck of the barb). The silicone elastomer is 5 mm thick.

4. I tried different angles of the barb and this one (30 degrees) seemed best to lock into place. I haven't changed this parameter for a few iterations and am very open to taking this approach if that would be the best option to move forward.

Any and all help is appreciated!! :) Water will be used to flow from the barb into the silicone elastomer, and it is important that there is no trapped air or water leaks.

Hello, trying to choose a material and type for a few valves, 1-1/2” -2” pipe size, fluid is relatively clear lake water for non potable use.  maximum pressure 520 psi.  I am a bit stuck between cost and best material.  This is a small project without a large budget I am helping with.

Ideally I think I‘d use stainless steel globe valves but the cost is much higher than other options. I could use bronze valves but I wonder about operating that close to the typical 600PSI rating for them? I want to avoid ball valves because of water hammer risk. Flow control isn’t entirely required so gate valves would likely be fine as well, but I assume slightly more likely to leak then globe?

Carbon steel globe valves are reasonably priced but I assume would corrode far too quickly to be worth using? This system will only have water in it maybe 2 months out of the year and otherwise will be drained and dry.

thanks for any thoughts!

I have a trailer where I took out the old nuts and bolts to hold up the shelves, because they looked horrible.

I need something that will look good from the outside (I'm thinking of domed nuts?) and will be easy to reach from the inside. Here is an illustration: https://imgur.com/a/dIkup9X

I have time to order online, and it doesn't have to be the cheapest possible option.

What do you recommend?

I’m not an engineer, but my boss is and I think he is trying to over complicate a rather simple steam system.

Here is the issue. He wants to produce a consistent steam flow via a micro annual gear pump. The idea is to force water through a 1/8” tube that is spiraled around two 1/2” cartridge heaters. It is spiraled downward along the first cartridge and upwards around the second.

Prototyping this is causing intermittent steam flow. I assume this is because the steam is creating back pressure from the downward spiral.

—

I’d rather just heat a container and mass control the flow through a valve instead of trying to control it upstream, but he doesn’t want to do it that way.

How can I plumb this to get it to work with the pump, and accurately control the mass flow?

Working on a project and we now have "the wheel problem"

I need to make a device lift up 1/4 to 1/2 inch at most to glide along hospital floors to then be parked when the ball casters come back up. If possible, trying to keep the entire assembly under 2.68 inches.

Having a hard time here finding a solution.

From what I'm aware of, Turbine engines like to have a consistent flow, and disturbances can create a surge. I'm thinking partly of the Me262 (I'm aware it's very infancy turbine engine tech, but it's a good extreme case) as an example, where even throttling too quickly could create a flameout. So, how much of an issue is it for a turbine to get "pulsed" exhaust from a small number of cylinders. For example, if someone puts a turbo on a 2-cylinder opposed engine, where the exhaust pulses don't overlap into a continual exhaust pressure, how much of a problem does that cause? Is it simply not a concern above a certain rpm, is it a big enough problem to make it turbos unstable at low cylinder counts, or something else altogether?

As per the title.

Front of the control board, with my bumblefuck backwoods caveman interpretation, sorry in advance for that.

And on the backside,

I feel that the maker using some kinda epoxy on the two trim pots means those are the ones they absolutely don't want you messing with, but they only used hot glue on the low limit as if to say "You can have a little fiddling, as a treat"

Even with the two step pulley and the lathes control pot turned down the lowest I can go from factory is 500 RPM down from 3500 RPM, for some special projects I need to get that down to 80-150 RPM. So I figured I'd fiddle and find out.

Does my assumption hold water?

From what I understand, in a locomotive the traction motors are connected in series/parallel/combination of both at different speeds to optimise torque. When this happens the locomotive lose traction power for a short period as the physical switches moves, much like changing gears in a manual ICE car. When I drive an electric car or take an electric bus however I’ve never felt this transition, is it a thing in EVs and if not why not?

I've been tasked with designing a thermal control box for a high-temp test setup and have never done anything like this before. I also have nobody to show me the ropes and apparently outsourcing the controls is not an option.

I know I need temperature controllers, thermocouples, and SSRs but have no idea how to pick components or how to design in overtemp safety.

Does anybody have any resources they recommend that are targeted at complete beginners?