Chinese Crankshafts (2012)
flycorvair.net
flycorvair.net
Don't get me wrong, Chinese do manufacture these robots too，but from the Chinese news reports I've read, the durability just isn't there, and they relies on either Germany or Japan for key parts.
Quality control is left up to the customer's oversight into the Factory's processes, and factory materials such as test fixtures or robots are usually bodged together using equipment that is so far out of whack with the task, its tantamount to using a sledgehammer as a pair of tweezers. I have literally seen SMT assembly work being done with a chisel soldering tip that is nearly five times larger than the components being soldered.
You want robots? Be prepared to write the software to drive them yourself and provide the hardware. Its nuts.
Swiss watches? Developed by British and French watchmakers escaping religious persecution in their home countries.
Japanese cameras and other consumer electronics? Started off as cheap knock-offs of Western products.
You learn a lot from importing technology and using it to copy stuff until you reach a level of skill where you realise you can do this just as well as the original makers.
That is the point where you start looking into other barriers to market share - like poor QC, dodgy reputation etc. (Also, that is probably the point where you start designing and building your own assembly lines, too.)
Chinese bullet train technology was bascially bought from Germany and Japan, and I've read mutiple times that they know how to manufacture it by designs (still rely on those two for some key parts), but don't know how to improve it coz don't know why.
But the propaganda made it sound like China invented it, and it's so advanced.
Anecdotally, once we had a couple of Chinese auditors in the workshop (Scandinavia) to assess the quality of a delivery we were about to make to a Chinese government agency.
Once they were satisfied that key parts - motors, pumps, power electronics - were made anywhere but China, they really only had two further questions - 'Where do we sign?' and 'When is lunch?'
But precision manufacturing is extremely difficult. There were a couple comments musing about aviation stuff. Let's put it this way. Russia is very good at certain types of manufacturing (e.g. rockets) to the point that NASA uses Russian rockets to launch its satellites. Russia (and Ukraine) have a ton of experience manufacturing airplanes (military and airliners). More recently, Sukhoi even managed to churn out a highly competitive, well received regional jet (the Superjet 100). Yet sales are lagging while Bombardier and Embraer dominate that market. Reliability is almost there, but there's next to no support. Without a support network you're dead in the water. To that end it appears that the Russians are taking this far more seriously than I'd expect the Chinese to. So beyond just manufacturing the part, there are cultural issues to overcome.
The Japanese are another example. Most people in this thread probably hold Japanese manufacturing in high regard (and for good reason). However, take a look at Mitsubishi. They're attempting to get in on the regional jet market as well. However, they're basically dead in the water and may end up scrapping the whole project. While there is a Japanese aviation industry, and Boeing partners heavily with some Japanese companies, the Japanese have never built a jet airliner and airliners are simply that complex.
So, sure, we'll eventually see more Chinese cars and higher quality Chinese consumer electronics. Sooner than later even. Aviation stuff? Maybe, but potentially not in my lifetime.
Don't know it? Hire someone. No equipment? Borrow or lease. No plant? Find one. Still can't make it? Place an order to someone who can.
The suggestions were basically: (1) don't think about manufacturing in China unless you visit the factory, owners, and engineers; (2) preferably, have someone onsite during manufacturing runs to do initial QA and refuse delivery if required; (3) assume the other party will cut costs anywhere you permit them to; (4) assume quality will drift cheaper, even if the previous batch was perfect.
A good friend does some manufacturing there for his business, and spends about half of the year over there coordinating.
So, yeah, some random order off the internet from another country? Routed through Taiwan? You're not going to have a good time.
The C919 is even further behind.
That's a somewhat gilded spin on the simpler truth, which is that in Chinese business it's shockingly easy to find hucksters willing to take your money for "work" with no real intention of producing a usable product. That is, he got "crankshafts" like he ordered, their work is done and it's on to the next mark.
Sure, a "trust process" can be a useful workaround for that problem. So can a functioning legal system that enforces that such criminals can't actually make money from their shenannigans.
But the root problem is that one system allows these people to run amok in the "legitimate" business climate and one doesn't.
FWIW: I don't buy for a minute that this has anything to do with chinese "culture". The problem here is that the PRC is a wild west environment that has no way for a foreign entity (local powers have more tools) to enforce a meaningful legal contract.
You just said what the gp post said in a different order. Both processes are at play here in both the US and China. I've met guys who did work for someone in the US, who then turned around and said, "You want to get paid? Sue me!" Yes, brazen as that.
That said, it can be argued that using legal mechanisms may be more reproducible and sustainable long term, than having charismatic people running around having relationships with everyone who must perform at a high level to ensure quality. Again, both are at play in both cultures, but having more of the mechanistic legal side may well allow for better scaling.
One thing that may make a difference between China and the US is the degree of independence of the judiciary, the degree of the rule of law, and checks and balances on the government. If the government gets up to too many shenanigans in the US, people will call them out, using principles, frameworks, and processes which are already laid out. In principle, you can't get jailed for doing this. It's in our rights to be able to hold the government to account. In China, there's just far less independence of the judiciary, less independence of the press, and more latitude for the government to pragmatically do what it wants. This means that crooked actors who want to bribe themselves into a little immunity have a more favorable market.
This is what you always have to ask yourself in any such context, government or corporate: Is concentrated power having its way with the public? Is there a way for people to call it out, or is dissent suppressed? Are people in power playing by rules, or are they making it up as they go along?
FWIW: I don't buy for a minute that this has anything to do with chinese "culture".
This is the big bone of contention between me and my chinese wife. She requested to me that I tell an outright lie about how we met on a dating site, so her coworkers don't rib her. I would rather just never lie, short of something like saving the life of an innocent from evil people. She seems to think my position is extreme and unreasonable.
I don't see how that logic is responsive. Obviously "it happens" anywhere in the world. The point was about frequency. I mean, sure, fraud like that by a machine shop probably happens in the US, but in the US it's fraud, which is a crime, and people go to jail for it. (Not to mention the fact that a machine shop that tried this would be sued for at least the liquidation value of its equipment, which is not insubstantial). So it's rare.
In China it's so common it's become a meme. It happens all the time, so much so that there's a posited "trust process" that exists to counter it. But obviously (seriously, obviously) that process doesn't work as well, because fraud is common there and rare here.
That's just silly. The Rule of Law works better than palm greasing and back watching, and to argue otherwise is just ridiculous. (And in context, holding up the PRC as an example of a libertarian wonderland is hilariously so).
(And your culture point makes the same logical mistake in reverse, assuming that since one chinese woman told a white lie and her husband was truthful that you can extrapolate honesty to a whole population. Again, frequency matters!)
I don't think you are thinking clearly and really understanding the terms you are using if you interpret a "bribery market in corruption" as some kind of "libertarian wonderland." No libertarian worth listening to would advocate for an environment without accountability and rule of law.
You've got things so near to 180 degrees turned around, it's a bit of a wonder and maybe a wee bit worrying.
(And your culture point makes the same logical mistake in reverse, assuming that since one chinese woman told a white lie and her husband was truthful that you can extrapolate honesty to a whole population. Again, frequency matters!)
No one actually says the things you're trying to put into other people's mouths. There, you're merely displaying your biases and what axes you're grinding. All I can offer is a factual account of my own anecdotal experience.
(In other words, I'm trying to have a nuanced discussion here, while you seem to be operating on the assumption that everyone's polarized at either extreme.)
I've seen one of those videos. In it, a group of chinese workers were forging a huge ring. There was indeed something "rednecky" about it, but as far as I could tell as a layman, they were legit forging the part. It's just that instead of all of the robot arms and mechanisms moving the metal around inside a factory (the next video was some German factory doing some similar part) they were using a crane and a forklift outdoors in a dirt yard. OSHA inspectors would crap their pants, but to me it looked like they were doing the same operations.
Although lawyers get blamed for a lot in U.S. aviation, I am going to make the case that you don’t get to see the good that they actually do. Putting emotion aside, think about this: Every year, countless people from outside of aviation refuse to sell products to, or work with, aircraft builders, citing the reason, “I don’t want to get sued.” Some of these people make good stuff that could be well used in experimental aviation. But a number of them make trash, or things that are not appropriate for planes, many of them have no idea of how aircraft work, and most of them have never even flown in a light plane. If those people make stuff for planes, and claim that their stuff is airworthy, they would get sued.
Vans Aircraft is a large, successful kit plane manufacturer. More new home built Vans airplanes fly each year than new Cessnas (or probably any other current aviation company, for that matter).
Prior to Vans amazing success, it was common for kitplane companies to run very lean and turn the whole company over (or liquidate the assets and turn them over) in the event of a lawsuit, thus avoiding an expensive legal fight.
A Vans airplane was involved in a double fatality. Even though the NTSB determined the pilot to be doubly at fault, a $35 million lawsuit was allowed to proceed in the US. Vans had to provide a legal defense. The lawsuit was eventually dismissed, but doubtless Vans was out a lot of money, both the years of legal defense and bad PR.
https://www.reuters.com/article/us-north-carolina-lion/lion-...
https://newsline.kitplanes.com/2015/10/20/vans-aircraft-sued...
https://newsline.kitplanes.com/2017/02/22/lawsuit-against-va...
I've flown an RV10 and and seriously looking into building one. Nothing about his accident has any influence on my decision process. The Vans kits are probably the best in the industry and section 5.27 of the plans clearly says not to use any sealant, including RTV, on fluid fittings. (Section 5 is a common chapter to all of the RV series and even comes with the practice kit.)
1. http://www.vansairforce.com/community/showthread.php?t=44934
PS your first link is about lions.
That may be my fault. That story (https://www.reuters.com/article/us-north-carolina-lion/lion-...) seems to be following me around today.
https://www.reuters.com/article/us-oregon-crash/oregon-famil...
Sorry about the lion link, not sure how it got in there.
I guess part of the problem is that get rich quick schemes do sometimes work, providing a false signal to others.
As a bonus, soon after the deal was finalized they discovered a Chinese vendor on eBay selling the (highly vertical market) part for a fraction of the retail price, but higher than their cost with the new manufacturer. It was obvious what was going on, but how do you sue a Chinese manufacturer who can close shop at the first sniff of lawyers and reopen six months later under a new name? They have the designs so they may as well own the IP, at least in China.
These are the kinds of mistakes a small business makes when trying to gamble and cut corners.
Exactly. Kind of like winning the lottery. The winner is all over TV and news bragging so it makes it seem so easy to win. If people had to sit and listen to everyone who played and lost nobody would play it.
A (reground) 50-year old cast crank sounds like a poor substitute in aviation applications.
Not to mention the material differences between a machined billet crank and part cast in sand five decades ago, subsequently salvaged and reworked.
In precision machining where tolerances are typically measured in thousandths of an inch that's way beyond unacceptable. At this point trying to make it work is throwing good money after bad. The fact that he didn't even realize it until he was trying to fit it into an engine means he did no QC on his own too. This whole endeavor was destined to fail from the start. He seriously needed a business partner with actual manufacturing experience.
Why he didn’t abort at that point is beyond me, other than ignorance (in which case he shouldn’t be build avaiation engines) or the above mentioned sunk cost. But even if the latter, he would have ended up selling sub-par parts whether he knew it or not (in which case he shouldn’t be selling aviation engines).
I have no sympathy for the businessman who had the cranks made, something that far out of spec should have never made it into a customer's hands. If you are serious enough to invest 30k in tooling to get parts made, you should also be consulting with an experienced engineer and lawyer who both have experience dealing with Chinese suppliers.
There is a reason forged and billet American performance car parts are expensive!
There is a huge amount of testing, engineering, and quality control that goes into a crank made by Bryant or Callies.
I put all forged moving parts into my Dodge engine build :-) It wasn't strictly necessary for the power levels, but what the hell.
But I did get a forged scattershield, because I like my feet.
China's industry is relatively new, and may not yet have gotten to this stage yet.
I recently read Andrew "bunnie" Huang's book "The Hardware Hacker", where he talks extensively about building electronics in China, and it sounds very familiar to this. Despite some problems with counterfeit SD cards, he eventually brought the Chumby to market.
So, it sounds like you can get great results and low prices, but you have to be able to keep your eyes on the process the whole way through, or find people you can trust who do.
But if you get it wrong, you get to write a story like Keyboard.io[1], as we discussed previously[2].
[1] https://blog.keyboard.io/post/181333242149/december-2018-a-s...
>Brady finds out that new forged cranks can be made for about $1000.
Bull shit, and I bet he knew it too. China can cost-cut some manufacturing by shifting the prices to human labor, but they cant drop the price on precision machining. Every US manufacturer I know who cuts cams or cranks is feeding billet stainless or billet high nickel into a 5 axis CNC. If its a big enough customer, they'll ship that part to another machinist to have them QC things like center-process and calculated c(pk) ratios.
>Compression dropped off, and an inspection showed that the exhaust valves were bent. Usually the only thing that can do this is putting the cam in several teeth off, something a lifelong motorhead like Steve isn’t likely to do.
Chinese manufacturing has about as much trustworthiness in it as the chinese communist party. Which is to say, im not surprised to see hidden rework on this part that caused a failure. heat-treated composite Steel is not cheap in china, so the pressure to rework is enormous. Whereas in the US we throw out NG spec pieces on the daily, an NG spec crankshaft at a thousand dollars is valuable enough to feed an entire village for the week.
>In the end, the Chinese kept all his money, he lost his business, his house, and a lot of the other things in his personal life unraveled.
speaking from experience, the chinese are just now getting around to manufacturing tooling that can withstand more than a few drops in the toolchest. high speed steel parts for example are still prone to fracture at ridiculously high rates. chinese fasteners are spot-on clones of german and american fasteners, but fail at much lower levels of force. Even the steel stamped to make bolts, cotter pins, and collars is riddled with QC variances and imperfections that can cause a part to fail in hours.
It is an aviation community in this case as well. They are re-purposing a car engine. It seems the loads on the crankshaft if it is directly attached to the propeller will be quite different that what the would be in a car. With a propeller there would be a bending component (propeller acting a gyroscope) besides the twisting component, especially when say doing aerobatics, while in a car the it will be mostly a twisting component.
So perhaps then cast vs billet becomes more important as one can withstand bending forces better than the other generally.
Cessna 421 is one of the common geared engine aircraft. Twin Bonanza, Navion, late Widgeons, R985s, and others also have geared engines, but they’re the vanishingly small minority of piston aircraft.
Common types (Cessna 172/182/210, Beechcraft Bonanza/Baron/Skipper, Piper Cub/Warrior/Arrow/Seminole/Seneca/Apache) are all direct drive.
Is this a significant component?
From what I've heard, a big thing with using automotive engines in aircraft is that aircraft engines spend most of their time at close to full throttle. In a car, however, average power output is probably 20% or even less of full power.
Now, I generally throw any fastener hardware that comes with Chinese kits out and use my own.
The good news is that the quality of Chinese goods is rapidly improving, if anybody remembers the absolutely rock bottom quality of Chinese made good 30 years ago, the products are absolutely improving. It's just that the rest of the world is working at such a level of quality that Chinese-made goods just aren't quite there yet.
Just wait for Chinese society to catch up and I have no doubt that in 30 more years "Chinesium" will represent some kind of unobtainable praiseworthy material that nobody else can seem to make.
I'm a little happy about this-- longevity of use, the same materials being re-used for decades. I'm just surprised.
What percentage of the aircraft cost is the delta between the Chinese and US made crank? 2k/80k? Does even make sense to cut corners here? For rotational and safety critical items I always use OEM or better in my street cars, what would drive aviators to not think the same?
Anyone know a us/eu manufacturer that makes/sells them (i would prefer spending 1k more in return for product quality)