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MITSUI SEIKI Craftsmanship

Asking from a place of total ignorance but; why wouldn't they use power scrapers? Is it cultural or is hand scraping required for the standard they are working to? I get it for the fine adjustments but for a "12 meter long" set of ways?!
 
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We have a boatload of large Mitsui Seiki 5-axis mills. Very accurate machines. Our oldest one was built in the mid 1980s and still being used today.
 
Mitsui Horizontal CNC mill I use reads 0.00001" and 0.0001 degrees.
.
biggest problem I have is temperature changes effecting parts probably from coolant
evaporation. holding +/-.0001"diameter on 10" bores is not always easy. the theory
is a ring gage gets colder smaller faster than a 1/2 to 2 ton part so the bore indicator
is zeroing to a temporarily small ring gage. outside machine the part and ring gage
after a few hours often read different .0001" usually I bore to max size and after it
is at minimum size at stabilized temperature
 
Is your shop temperature consistent? Moore wrote the ideal temp is 68 F degrees. Also sun shining through a window on the machine or AC or ceiling heater blowing on one side can change hoe the parts can be consistent. Check the gibs on the slides. Also some machines have spindles with coolant. Holding. 00005 is tough with all the factors to think about.
 
Is your shop temperature consistent? Moore wrote the ideal temp is 68 F degrees. Also sun shining through a window on the machine or AC or ceiling heater blowing on one side can change hoe the parts can be consistent. Check the gibs on the slides. Also some machines have spindles with coolant. Holding. 00005 is tough with all the factors to think about.
Oops I posted this in the wrong thread.
 
This is a nice - beautiful video. Someone asked about "why don't the power scrape"?
BIAX calls me their International teacher as I have taught scraping classes inside their plant in Germany. They claim the Japanese builders buy power 1/2 moon flakers but don't buy power scrapers because the reciprocating blade leaves a burr at the end of the stroke. Handscraping doesn't leave a burr when the scoop scrape. The Japanese have a manual that teaches them how to machine and scrape and it teaches no burr is allowed. The BIAX Swiss factory has done studies that shows the Japanese are wrong, but the Japanese won't change their technology on hand scraping.
 
This is a nice - beautiful video. Someone asked about "why don't the power scrape"?
BIAX calls me their International teacher as I have taught scraping classes inside their plant in Germany. They claim the Japanese builders buy power 1/2 moon flakers but don't buy power scrapers because the reciprocating blade leaves a burr at the end of the stroke. Handscraping doesn't leave a burr when the scoop scrape. The Japanese have a manual that teaches them how to machine and scrape and it teaches no burr is allowed. The BIAX Swiss factory has done studies that shows the Japanese are wrong, but the Japanese won't change their technology on hand scraping.
Very cool , so it is cultural with the japanese. I had a feeling that you would chime in with the answer. Thanks Rich
 
Interesting, but oh my aching back. Aren’t I glad that I don’t have to do that anymore !

They guy is wrong when he says you can’t machine components to a greater level of accuracy than the machine you’re working on. I’ve seen guys turn out great work on old, worn, machines. That’s why you have skilled men doing the job and not somebody you’ve just dragged in off the street.

Regards Tyrone
 
They guy is wrong when he says you can’t machine components to a greater level of accuracy than the machine you’re working on. I’ve seen guys turn out great work on old, worn, machines. That’s why you have skilled men doing the job and not somebody you’ve just dragged in off the street.

Regards Tyrone
If you look into the history of machine tool development you'll find some interesting solutions to machine inaccuracies.

For instance, in developing accurate lead screws. Once a lathe had machined the threads of a leadscrew for a new lathe, it can be measured and inaccuracies mapped. Then, mounted on a special machine with a cam modified leadscrew nut, the next leadscrew can be machined with corrections for problems with the first.
 
Mitsui Horizontal CNC mill I use reads 0.00001" and 0.0001 degrees.
.
biggest problem I have is temperature changes effecting parts probably from coolant
evaporation. holding +/-.0001"diameter on 10" bores is not always easy. the theory
is a ring gage gets colder smaller faster than a 1/2 to 2 ton part so the bore indicator
is zeroing to a temporarily small ring gage. outside machine the part and ring gage
after a few hours often read different .0001" usually I bore to max size and after it
is at minimum size at stabilized temperature
Tom, where have you been? Thought you were running a big bridgemill.
 
This is a nice - beautiful video. Someone asked about "why don't the power scrape"?
BIAX calls me their International teacher as I have taught scraping classes inside their plant in Germany. They claim the Japanese builders buy power 1/2 moon flakers but don't buy power scrapers because the reciprocating blade leaves a burr at the end of the stroke. Handscraping doesn't leave a burr when the scoop scrape. The Japanese have a manual that teaches them how to machine and scrape and it teaches no burr is allowed. The BIAX Swiss factory has done studies that shows the Japanese are wrong, but the Japanese won't change their technology on hand scraping.
Does Biax publish these studies?
 
No. I wish. When I was in Taiwan they also talked about the Japanese manual talking about only push and lift or scoop scraping. No burr at the end of the stroke. Matt you've power scraped and know first hand if you stone it properly the burr is not an issue. How's your Polish lathe working out?
 
No. I wish. When I was in Taiwan they also talked about the Japanese manual talking about only push and lift or scoop scraping. No burr at the end of the stroke. Matt you've power scraped and know first hand if you stone it properly the burr is not an issue. How's your Polish lathe working out?
I passed on the polish lathe and bought a big single owner L&S its 26" x 108".
 
My experience with Japanese engineering culture (which mirrors the general feeling) is that saving money is rarely a consideration to changing a working process. Only something that actually provides a quality improvement would be a consideration for change. As good as Biax's are, it would be arguable that they offer speed over any significant quality enhancement compared to a master scraper. Hand scraping is a tradition in these factories, it is treated as an art, with apprenticeship and years of mastery. They get a known, repeatable result with the only downsides being cost and time, and again, those are almost never serious factors in the realm of high end Japanese manufacturing. Using machines to scrape would likely be an embarrassing sign of profiteering, or admission that the workforce lacked talent. So although I believe there may be technical issues like the burr formation, or less interaction (QA) of someone going over every cm² with a fine toothed carbide comb, or other reasons that could likely be worked around, I think that the biggest reason is just tradition and not wanting to deal with the unknowns that any process change will surely bring. This resistance to change is more often than not a good thing, and the Japanese are real tide fighters.

Having said all that, there are Biax's over here. Not a lot, but I've been able to pick up 3 of them so far. They are sold new by the local distributor at astonishing markups over the already insane prices over there. They are shown at the Trade Shows I've attended, and they are certainly in use even if there would be little reason to publicise that fact.

I leave you with a little "A" grade, hand scraped, Obishi-Keiki block that just arrived this morning. I'm sure someone out there could do something similar with a Biax, or at least hit the same numbers, but would it be as beautiful? Maybe that's all it is...

OK 125.jpeg
 
My experience with Japanese engineering culture (which mirrors the general feeling) is that saving money is rarely a consideration to changing a working process. Only something that actually provides a quality improvement would be a consideration for change. As good as Biax's are, it would be arguable that they offer speed over any significant quality enhancement compared to a master scraper. Hand scraping is a tradition in these factories, it is treated as an art, with apprenticeship and years of mastery. They get a known, repeatable result with the only downsides being cost and time, and again, those are almost never serious factors in the realm of high end Japanese manufacturing. Using machines to scrape would likely be an embarrassing sign of profiteering, or admission that the workforce lacked talent. So although I believe there may be technical issues like the burr formation, or less interaction (QA) of someone going over every cm² with a fine toothed carbide comb, or other reasons that could likely be worked around, I think that the biggest reason is just tradition and not wanting to deal with the unknowns that any process change will surely bring. This resistance to change is more often than not a good thing, and the Japanese are real tide fighters.

Having said all that, there are Biax's over here. Not a lot, but I've been able to pick up 3 of them so far. They are sold new by the local distributor at astonishing markups over the already insane prices over there. They are shown at the Trade Shows I've attended, and they are certainly in use even if there would be little reason to publicise that fact.

I leave you with a little "A" grade, hand scraped, Obishi-Keiki block that just arrived this morning. I'm sure someone out there could do something similar with a Biax, or at least hit the same numbers, but would it be as beautiful? Maybe that's all it is...

View attachment 415155

To my eye i see burrs at the end of those scrape marks. It looks like a nice surface, how does it blue up? Its nearly impossible to get a checkerboard pattern that blues perfectly without destroying the 40% contact you after.

Thanks for sharing the cultural perspective!
 
To my eye i see burrs at the end of those scrape marks. It looks like a nice surface, how does it blue up? Its nearly impossible to get a checkerboard pattern that blues perfectly without destroying the 40% contact you after.
To be frank this isn't a great example of what Mr. King was talking about as this surface finish is more flaking than scraping. These blocks are not so much used as surface masters as they are relied on for parallelism and perpendicularity. These Mass Blocks were very popular over here, come in a range of sizes and can be bought second hand for what seems like less than the cost of the cast Iron. This one was a pristine example though, and I paid more for it than I usually would (it was just so pretty), but far far less than it would sell for new. New Japanese tooling isn't cheap at all.

When you see the (lewd :LOL: ) videos of Japanese Style scraping, it is clear that the motion they use minimizes a burr at the end stroke, but there is still often some burr formation, and they stone regularly just like any scraping process. I believe they get a more consistent scrape profile, and that likely helps when zeroing in on the surface, but I find it implausible that the burr creation is the only (or even main) factor for sticking with hand scraping. At some point I will get off my ass and visit some of these manufacturers, and I assure you I will question them on this subject as I'm sure there is some additional insight or reasoning behind this, even if it is apocryphal or misguided.
 








 
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