To be fair, if you don’t have the files. This is an easy way to make a prototype and fit it, and then if it fits you can order it in metal. This is a cheaper proces in iternating in metal from the start
Ah … ! What’s happening? it thought.
Er, excuse me, who am I?
Hello?
Why am I here? What’s my purpose in life?
What do I mean by who am I?
Calm down, get a grip now … oh! this is an interesting sensation, what is it? It’s a sort of … yawning, tingling sensation in my … my … well I suppose I’d better start finding names for things if I want to make any headway in what for the sake of what I shall call an argument I shall call the world, so let’s call it my stomach.
Good. Ooooh, it’s getting quite strong. And hey, what’s about this whistling roaring sound going past what I’m suddenly going to call my head? Perhaps I can call that … wind! Is that a good name? It’ll do … perhaps I can find a better name for it later when I’ve found out what it’s for. It must be something very important because there certainly seems to be a hell of a lot of it. Hey! What’s this thing? This … let’s call it a tail – yeah, tail. Hey! I can can really thrash it about pretty good can’t I? Wow! Wow! That feels great! Doesn’t seem to achieve very much but I’ll probably find out what it’s for later on. Now – have I built up any coherent picture of things yet?
No.
Never mind, hey, this is really exciting, so much to find out about, so much to look forward to, I’m quite dizzy with anticipation …
Or is it the wind?
There really is a lot of that now isn’t it?
And wow! Hey! What’s this thing suddenly coming towards me very fast? Very very fast. So big and flat and round, it needs a big wide sounding name like … ow … ound … round … ground! That’s it! That’s a good name – ground!
I wonder if it will be friends with me?
Yeah, but to get there, you need a prototype. There’s nothing wrong with testing the fit using 3D printing before you order a copy in real materials, just don’t put it under any load.
You could print it with normal plastic filaments, but those can deform and screw with the measurements if you’ve got a really tight fit, so metal printing is a good use there.
Aerospace manufacturing has a paper trail longer than you can imagine. The company selling this part can tell you (well, the FAA) the exact ingot out of the foundry and every single process and every person who has touched it since then.
No machine shop will take this job; the moment this guy is unable to produce a serial number and paperwork from an approved manufacturer (likely during preflight if not installation) the FAA will track down the owner of said shop. At best that owner will lose their business and pay a massive fine, at worst spend a good long time in prison.
The FAA doesn’t fuck around and for that I am thankful.
Depends on how much effort went into reverse engineering the part, but most likely when tolerancing enters the conversation. Most machine shops aren’t able to hit those tolerances and would laugh you out of the shop.
A shop that can hit those tolerances will kick you out of the shop; there’s a good chance they already work in aerospace. They have a deeply vested interest in avoiding the accompanying FAA inquiry should it be installed or, Satan forbid, actually flown.
A non-aerospace shop capable of meeting those tolerances would start laughing at the desired price point. Purchasing a suitable blank alone would cost over $1500, much less cover the actual machining.
A part like this can have some tolerance because it experiences wear and tear and oxidation, if it had to be down to a few microns perfection, the helicopter wouldn’t fly in both hot and cold temps even on day one. Die and investment metal casting especially with CNC machining, which are common enough processes in metal shops, can actually get down to single digit microns. But this is all moot as no one would ever do this for many reasons.
It would have to be an experimental aircraft. Someone died recently when they installed a 3D printed intake that melted on their experimental single seater.
I get what you’re saying but this is what is called the “Jesus Nut”. That’s because it’s one piece that essentially holds your entire helicopter up. To quote the Wikipedia page: …“whose breakdown would result in catastrophic consequences, the suggestion being that in such case the only thing left to do would be to pray to Jesus, or that the component’s importance could be likened to the importance of Jesus to Christianity.”
You don’t prototype this. You don’t make these. You get the tested, real part. There is no scenario in which making your own is advisable. Unless you’re an engineer for an aircraft manufacturer who is going to be doing rigorous testing then you should just buy the part ready made and certified.
Absolutes always get me scheming. What if you’re stuck on a deserted island with only a working 3d printer and a helicopter missing this part? What then? Yeah probably swim.
You build a boat out of the helicopter and 3d printed parts. I’ll be a bad boat, but the best case scenario for this 3d printed part is that it breaks under static load
So the design has never changed since it was made? The engineers have never needed to figure out an upgrade or slightly different way of doing it?
Of course randos don’t make them in their garage, but somebody does make them, and I don’t see a problem with experts incorporating this into their workflow. I don’t know why you do?
I think we’ve lost the context here. The person in the photo self-describes as a consumer - they should not be making this. That’s the joke.
Somebody who would be prototyping something like this works for an aircraft manufacturer, and there’s probably less than a thousand of such people in the world. If you are one such person you know so.
You can also print in different metals with various processes like laser sintering, still though, there are some things you might not want to skimp on: Probably best to stick to approved parts.
To be fair, if you don’t have the files. This is an easy way to make a prototype and fit it, and then if it fits you can order it in metal. This is a cheaper proces in iternating in metal from the start
If the choice is between being out $1,590 or plummeting to my death in order to save a few hundred bucks, then I’ll just pay the $1,590.
They call it the Jesus Nut for a reason.
Because it makes Jesus Nut?
Because if it fails, only Jesus can save you
Bull honkey, knock the rust off 'er, slap on some grease and she’s good as new
Got that Alaskan Airframe and Powerplant license, I see.
I reckon that’s right pardner
Spoken like a true Boeing engineer.
on the radio “We got him, back him and tag him.”
Ain’t no whistleblowin goin round here
That’s what has me grinning! I’m not replacing a Jesus nut with anything that didn’t come straight from the manufacturer.
I’ve actually flown Robinson helicopters, and there’s no nut that looks like this on the helicopter.
So, probably a joke.
Yeah you just have to deal with mast bumping, as if thats any less worrying.
Mast bumping is such a gentle term for the main rotor just fucking off and the helicopter going from an aircraft to a falling object.
You’ve flown Robinson?
Willingly?
And lived? Brave soul.
Good news is, that part ain’t getting off the ground. Bad news is, the rotor might get kinda fast first
I’d rather plummet to my death.
No. No.
For this part? No. You want the real deal. The proper metal. The proper alloy, annealed correctly.
Yeah, but to get there, you need a prototype. There’s nothing wrong with testing the fit using 3D printing before you order a copy in real materials, just don’t put it under any load.
You could print it with normal plastic filaments, but those can deform and screw with the measurements if you’ve got a really tight fit, so metal printing is a good use there.
Aerospace manufacturing has a paper trail longer than you can imagine. The company selling this part can tell you (well, the FAA) the exact ingot out of the foundry and every single process and every person who has touched it since then.
No machine shop will take this job; the moment this guy is unable to produce a serial number and paperwork from an approved manufacturer (likely during preflight if not installation) the FAA will track down the owner of said shop. At best that owner will lose their business and pay a massive fine, at worst spend a good long time in prison.
The FAA doesn’t fuck around and for that I am thankful.
Also, one-offs aren’t really allowed outside of r&d. Everything has to have at least one piece in a batch go through testing, including destructive.
How is the machine shop supposed to know it’s an aerospace part? The customer could just give them a reverse-engineered CAD file.
(Academic question, because making this part actually work will cost >$1500 without economies of scale)
Depends on how much effort went into reverse engineering the part, but most likely when tolerancing enters the conversation. Most machine shops aren’t able to hit those tolerances and would laugh you out of the shop.
A shop that can hit those tolerances will kick you out of the shop; there’s a good chance they already work in aerospace. They have a deeply vested interest in avoiding the accompanying FAA inquiry should it be installed or, Satan forbid, actually flown.
A non-aerospace shop capable of meeting those tolerances would start laughing at the desired price point. Purchasing a suitable blank alone would cost over $1500, much less cover the actual machining.
A part like this can have some tolerance because it experiences wear and tear and oxidation, if it had to be down to a few microns perfection, the helicopter wouldn’t fly in both hot and cold temps even on day one. Die and investment metal casting especially with CNC machining, which are common enough processes in metal shops, can actually get down to single digit microns. But this is all moot as no one would ever do this for many reasons.
It would have to be an experimental aircraft. Someone died recently when they installed a 3D printed intake that melted on their experimental single seater.
How is the shop supposed to know the funny bolt someone asked them for was going in a helicopter?
I get what you’re saying but this is what is called the “Jesus Nut”. That’s because it’s one piece that essentially holds your entire helicopter up. To quote the Wikipedia page: …“whose breakdown would result in catastrophic consequences, the suggestion being that in such case the only thing left to do would be to pray to Jesus, or that the component’s importance could be likened to the importance of Jesus to Christianity.”
You don’t prototype this. You don’t make these. You get the tested, real part. There is no scenario in which making your own is advisable. Unless you’re an engineer for an aircraft manufacturer who is going to be doing rigorous testing then you should just buy the part ready made and certified.
Lol the meme is the picture on the wiki mirrored and edited
Absolutes always get me scheming. What if you’re stuck on a deserted island with only a working 3d printer and a helicopter missing this part? What then? Yeah probably swim.
Use the radio in the helicopter to call for help?
Gilligan already broke it.
You build a boat out of the helicopter and 3d printed parts. I’ll be a bad boat, but the best case scenario for this 3d printed part is that it breaks under static load
I’d say cry, the small loss of water will bring the sweet release of death one step closer.
If an aerospace engineer made one of these he would no longer be an aerospace engineer.
Everything else you said is correct.
Hah, Jesus nut
So the design has never changed since it was made? The engineers have never needed to figure out an upgrade or slightly different way of doing it?
Of course randos don’t make them in their garage, but somebody does make them, and I don’t see a problem with experts incorporating this into their workflow. I don’t know why you do?
I think we’ve lost the context here. The person in the photo self-describes as a consumer - they should not be making this. That’s the joke.
Somebody who would be prototyping something like this works for an aircraft manufacturer, and there’s probably less than a thousand of such people in the world. If you are one such person you know so.
I’m one of those people and there’s absolutely no way I could produce a safe copy of this for less than $1590.
The part already exists though?
You can also print in different metals with various processes like laser sintering, still though, there are some things you might not want to skimp on: Probably best to stick to approved parts.
It wouldn’t surprise me if such a critical part was cast as a single metal crystal. The stresses on that rotor mist be unbelievable.
Pretty sure you don’t want a be doing that with an aircraft.
I’m sure it’s safe if you can do it correctly, but I would not trust myself like that