/diy/ - Do It Yourself

American engineers everyone.

>>1316533
Is that just two bolts head together with a nut?

Why?

>>1316533
D^2pi/4 × 36ksi = Pn

Pn/2 = weight one bolt holds

>Trash thread
This thread is now about posting the dumbest ideas youve had, like OP's

>>1316543
I made an ass dildo out of wood from home depot once

>>1316533

Depends how much weight it has to hold, but as a general rule, no.

Get some threaded rod.

>>1316549
How'd that go?

>>1316560
Splinters in my sphincter

>>1316558
>Depends how much weight it has to hold, but as a general rule, no.

sometimes you have to take a risk, anon.

https://en.wikipedia.org/wiki/Hyatt_Regency_walkway_collapse

>>1316570

Holy shit how did no one see jail time for this...

>double the lode
>put 100% of weight on the weld
>kill 114 people by dropping 60 tons of concrete and steel on top of them

I'm no engineer and even I can see how fucking stupid that plan is, those deaths are 100% avoidable but they didn't want to because they would have to be careful not to bang around the threaded rod.

>>1316570
>Those people who could walk were instructed to leave the hotel to simplify the rescue effort; those mortally injured were told they were going to die and given morphine.

>those mortally injured were told they were going to die and given morphine.

Holy shit

>>1316601
Standard three-tier emergency triage:

1. Those who will likely survive without treatment.
2. Those who will likely survive with treatment.
3. Those who will likely not survive even with treatment.

You only exhaust limited resources on treating the second group.

>>1316601

Why waste limited time and medical supplies in order to extract a corpse?

>>1316570
>One victim's right leg was trapped under anI-beam and had to be amputated by a surgeon, a task which was completed with a chainsaw.

>>1316620
the absolute STATE of american medical care

>>1316620

>tfw your lying there while this guy is revving up the stihl 090 to overbuck your leg.

The distant sound of someone in the neighborhood cutting a tree would trigger some real PTSD

>>1316569
>Name my band, /diy/

>>1316615
>>1316616
No no I know that, but holy shit

>>1316620
and that

That just... that sounds horrific

>>1316620
>ok hold still Bob
>trust me
>Im a doctor

>>1316620
>completed with a chainsaw
hmm that wouldn't be too hard

>faceshield because safety
>fill oiler with that sterilizer solution
>fully depress trigger
>laugh as blood spatters everywhere

>cauterize with oxy-acetylene rig
>put patient in backhoe bucket for extraction

>>1316570

Interesting how the image in OP and the question of it holding weight had me thinking about the exact same thing.

>>1316620
>DIY does First aid

>>1316673
Fuck dragging the gas-axe in there, hose clamps nigga!

>>1316533
There are many reasons

One being that you have no business securing a diving board

How about you go get a pro before you kill someone

>no one loves me
>they just walk right past
>take a look at the price and keep walking
>yep, there he goes right into the shit bin of budget galvanised, mild steel fasteners

>so ronry

>>1316717
I think about you most nights, 12.9

>>1316570
Why the hell use a C beam for this anyway?
Minimally they should have put in a steel plate to carry the load out to the walls.

>>1316770
the load should have been fine if the original plan was followed

>>1316650
When your paramedics were corpsmen in ww2, they have seen some shit.

>>1316778
The general gore and triage of "you gonna die, have some morphine" even regular EMTs might have seen
The Saw movie type stuff, not so much. It might have gone far beyond even what normal army medics would have seen in the war.
It mentions that rescuers had to dismember corpses to reach survivors.
>dismember (assumed) corpses
Are you sure that guy was dead when you used a tow chain to tear his body away from his legs, or was he just in shock? The woman you used a chainsaw to cut the torso into pieces to reach the guy behind, was she dead or just unable to respond because she could only take shallow breaths in that tight spot?
>>1316770
>>1316774
I couldn't find a good reason for them to weld 2 C beams together rather than square tubing, perhaps with C beam tacked on to help with twisting forces. But even if they followed original design, specs weren't strong enough. I'd at the least think they could have just gone with cables alternating between some attached to the top walkway and others passing through to the lower to keep their fancy art look. They could have hid it in pipes if they wanted a smooth look.
Someone with more knowledge, to keep their original look could they have just had the threaded rod extend an extra couple feet then solid rods drilled and tapped to screw on for a couple feet, or even connect 2 rods with a drilled tapped solid rod like a turnbuckle?

OP/DIY: bad designs kill, don't cut corners

>>1316704
Calm down bro there'd only be like two, three kids on it, tops

>>1316533
>attaching two bolts by a nut, between them
Literally more expensive than just buying threaded rod, you can't be serious

>>1316534
fpbp

nigger

>>1316885
What blacked.com scene is this?

>>1316533
Use a coupling nut ya drangus. Tighten it up and either use thread lock or hit each end with a tack weld

>>1316801
>to keep their original look could they have just had the threaded rod extend an extra couple feet then solid rods drilled and tapped to screw on for a couple feet, or even connect 2 rods with a drilled tapped solid rod like a turnbuckle?

exactly. Imagine being the construction crew looking at the plan and saying " you want us to thread a nut 20 fucking feet up a threaded rod to hold the walkway? So many better ways...

>>1316906
>tac weld it
Why the fuck, just use metal rod then

>>1316885
I'd knead that dough if you get what I'm saying.

>>1316954
>I'd knead that dough if you get what I'm saying.
I'm unsure what you mean, could you elaborate please.

It will take time, but vibrations will unscrew it.

>>1316982
It's a dive platform so it's going to have people jumping on it.

Seems like a good time to use one of these.

>>1316930

>>1316543
About 10 years ago I had a friend who was convinced that we should make a coffee machine with WiFi. I told him it was a stupid idea because... Oh wait...

>>1316588

>those deaths are 100% avoidable but they didn't want to because they would have to be careful not to bang around the threaded rod

It was more than that. The design was not constructable. It would have required threading the nuts 20 feet up the rods.

>>1317599

>>1316801

>Someone with more knowledge, to keep their original look could they have just had the threaded rod extend an extra couple feet then solid rods drilled and tapped to screw on for a couple feet, or even connect 2 rods with a drilled tapped solid rod like a turnbuckle?

No, the failure point was the threads, they were stripped off the rods (or the threads were stripped off the nuts, can't remember which but not that important).

Increasing the length of thread engagement doesn't effectively increase bearing capacity as the first few engaged threads are always carrying a significant portion of the load; after about one diameter of length the additional threads aren't adding anything to strength. This is why you rarely see fasteners with shapes like you describe (long and cylindrical rather than torus-shaped) unless they are performing some other function (such as protecting the screw threads or, like a turnbuckle, providing room for adjustment).

Either way the tensile strength of the rod is going to exceed the shear strength of any threads.

>>1317607
>Either way the tensile strength of the rod is going to exceed the shear strength of any threads.

not what a mechanical engineer told me. He said that for "ordinary" fasteners, meaning standard threads, once you have more than 3 threads engaged it won't help because the rod will break before it can shear more than 3 threads.

I don't follow your claim that the first few threads carry most of the load.

>>1317603
I like these.. no extra stuff required.
Makes hanging another layer of cable ladder so damn easy.

>>1316543
I thought about making a premium dildo made of 999 silver. 8 inches long, 1.5 inches wide, solid.

Then I realized that it would weigh about 8 pounds.

>>1316885
I kneed more.

>>1316620
>One of the great challenges of the rescue operation was that the hotel's sprinkler system had been severed by falling debris, flooding the lobby and putting trapped survivors at great risk of drowning. As the pipes were connected to water tanks, not a public source, the flow could not be stopped

>>1317612
>I don't follow your claim that the first few threads carry most of the load.

In a tightened joint, say 10 threads of engagement. The first thread holds about 55-60% of the load with subsequent threads holding less and less, until the 7-10th thread have almost no load at all on them

Poisson much ?

Due to the tension & compression of ALL materials

>>1317614
these are good for light/decorative loads


YFW most cable suspension bridges use this type of connection. And why occasionally siad bridegs must under go re-cabling (they stretch)

>>1317603
>>1317614

Pic related

>>1317612

>not what a mechanical engineer told me. He said that for "ordinary" fasteners, meaning standard threads, once you have more than 3 threads engaged it won't help because the rod will break before it can shear more than 3 threads.

Let me restate what I said. For a given load, it's easier to carry it using the tensile strength of the rod than the shear strength of the threads. That is to say it's much more practical to design/select a rod that can carry in tension a given load than it would be to design/select a nut that can carry the same load via thread engagement.

That was the basis of the Hyatt Regency KC example, if the engineer had tried to design the walkway structure such that the load of the entire structure was carried by the threads rather than the (much smaller) load of a single walkway, it would have resulted in much larger threads (in turn requiring much larger rods), which would have defeated the purpose of the design.

Generally when selecting a fastener you always want a nut with a proof strength (ultimate load the threads can carry without failure) greater than the tensile strength of the rod. But three threads (3 x lead) is arbitrary. Generally the distance (the thickness of the nut) is one diameter of the rod. After that additional thread engagement not adding anything to strength.

>I don't follow your claim that the first few threads carry most of the load.

Most nuts are not as hard as the bolts to which they are threaded. The reason is that if they were you would basically have zero tolerance for differences in the thread dimensions between nut and bolt to get full engagement. Nuts are softer so that the first engaged threads can yield and distribute the load to the next threads. But for the threads to yield in the first place they have to be supporting a greater load than the others.

>>1316549
>ass dildo
>ass opposed to a throat dildo?

>>1317639
>use this type of connectio

>>1317627
how does that work?

even if there's no valve on the tank (and why the fuck wouldn't there be) just drain the tank

>>1317713
Perhaps they couldn't even get to the tanks (they'll be high up, maybe even on the roof). Even if they could get to them draining them may not be easy, doing so could still flood the building unless they hook up a hose to get the water out of the building.

As for why there wouldn't be a shut off valve, that would be another area for failure and has the risk of some idiot shutting it off and not opening it back up.

>>1316533
Not enough thread. What you want is a turnbuckle. And probably some locktite.

>>1317643
t. virgin manlet

>>1316569
Splincter

>>1318760

The results of an advanced technique. Beautiful

>>1317374
No one actually buys these. Only peak californian soyboy "I learned computers!" types do, and then they go into a closet forever because the type of person who wants to Le Automate They're Home :^) drinks Monster or nothing at all anyway

>>1318795
Check out juicero. DRM fruit juice.

Top kek.

https://failures.wikispaces.com/Kansas+City+Hyatt+Regency+Walkways
Good shit