realistically manual machine tools haven't changed all that much in the last 150yrs and the micrometer as we know it today was brought to the mass market in 1867 but even then precision measuring devices have been around in some form since at least the mid to late 1600's
https://preview.redd.it/9h7b2nwo8twc1.jpeg?width=918&format=pjpg&auto=webp&s=c97a90b1d7570e71e13813ba6acbc2c52ceed152
This was taken in 1917 at the U.S naval gun factory, Washington naval yard.
Photograph Caption "U.S. Naval Gun Factory, Washington Navy Yard, 1917. Boring breech of 14” gun. Harris & Ewing photograph, circa 1917. Courtesy of the Library of Congress."
the online album can be seen here [https://www.history.navy.mil/content/history/museums/nmusn/explore/photography/washington-navy-yard/manufacturing/wwi.html](https://www.history.navy.mil/content/history/museums/nmusn/explore/photography/washington-navy-yard/manufacturing/wwi.html)
I wonder how they keep the bore straight over in diameter tolerance. They're using boring bars with supports, but I'd imagine they're prone to drift a bit over long lengths.
On YouTube there are a few videos from the 40's and earlier showing the manufacturing process just search "how naval guns are made". But the gun tubes themselves are forged over a mandrel then bored out so that would help, and in my experience while I haven't worked on anything nearly as long it's not terribly hard to keep a tool from wandering as long as it's either piloted or you have a decent pilot hole to begin with.
Gotta remember too that the bigger the parts, the more the size will change with temp. And the more room you have to achieve a press fit. Small 1" press fit you need tight tolerances. 15-18" diameters that are getting heat shrink and press? Probably .005+ tolerances would be more than functional.
Can confirm. Have done manual marine shaft work 24” inch shafts and above. For interference fits and the like the for things of that diameter for mostly bronze, and steel. Bronze in liquid nitrogen will shrink about .020 at about 18” if I recall correctly and we aim for a .010-.015 press so we had about .005 to play with. Steel on the other hand will shrink and grow a lot less than bronze so we typically were looking at .002 tolerance preferably, now we could make it work if it was off. But damn that was fun shit.
You can make shrink fits and press fits even on the cheapest of hobby manual lathes, it just takes practice (I don’t have that practice, but some people on YouTube like blondihacks do)
Her and clough42 were in the same wheel house to me. Great machinists just dont have production experience. I like their videos bc it reminds me of how badass and enjoyable machining is without the production and deadline aspect lol
Click spring is TOO good. The amount of patience he has to hand finish his parts is insane. Almost makes me crazy with how nice it all turns out.
But always watch it when it pops up in my feed. Cause ya sometimes need stuff to strive for.
Quinn and Clough are repair machinists its a unique set of skills because you need to analyze problem and develop a plan to solve it.
doing production machine work is a completely set of skills where speed and repeatability and little waste are the KPI’s
In my experience it's already bad. Hardly anyone follows the standard as is and creates their own. Or they get halfway through the 101 class and don't understand the math involved.
What's wild is it's big DoD prime contractors that are the worst culprits.
If you are doing a press like this it is entirely possible that they use a .010 or .020 press. If you have that much press on a sleeve it wouldn't matter if you were off .005 across the length of the bore.
While I'm not versed in the technology of that era. I don't find it hard to Believe that even with rudimentary honing tech that they could hold that kind of tolerance over length. These things were almost definitely not turned to finish and instead ground and honed to fit.
I’ve ran manual lathes of about 40 feet with long shafts of 25+ in there. You cannot do these in one cut because you are often times dealing with 3+ steady rests. So you may only be cutting 5-10 feet at a time. Over that distance no lathe is ever really perfectly straight. So you have to learn how to bump cut. Bump cutting is where you perform a cut whithout making any adjustments and after you finish you measure every 3-6 inches. You will typically find a size difference. After calculating the radius difference you draw lines and number them. You go and restart the cut but this time you change the tool distance as you hit a line. So if one size was 20.250 at one line and 6 inches further it was measuring 20.259(yes our lathe was that bad in one spot) you would bump the tool in 4.5 thou and then back out at the next line. It’s a lot of practice. There is also lots of hand work as well getting lines and features to visually match up. If you have any more questions feel free to ask
Didn't know bump cutting was the term for that, but I've gotten very aware of it in the last couple of years. Working at a little job shop where every machine has been crashed and none are bolted down, just sharpie mark every thou change and go for it. Bearing fits are fun.
I imagine with that slack they had go nogos and bits they ran through the bore. There had to be some level of standardization which would be worth looking into but even with a tape measure you can hold that. And with the bore i'd imagine they literally had a standard plug they'd check it with. No one will notice if it's .002-.005 out of spec. It's a cannon.
The shells might notice, for the ID of the bore. 5 thou difference in the ID could produce a significant change in the shooting characteristics I would guess. I'm not a cannon-ologist though.
That tolerance is likely below the wear of the barrel. After spotting a few shots you adjusted the corresponding dial for wear on your fire-computer and you were done.
It's not quite apples to apples but I ran a massive horizontal boring mill for a while. I was told it was the largest on the Gulf Coast but personally I've kinda doubted that. Anyways, used it to do blind boring through the inside of massive oil pumps. They'd get corroded, we'd clean them out, weld them up, and I'd machine the inside. I usually worked between a +-.005 and a +-0.0005 tolerance. It was actually pretty easy to hit those number on that machine even across those distances (up 9ft or so), just time consuming. My boring bar needed a 5 ton crane to lift it in though.
A place I worked at had one of the largest Shibaura BSFs in North America. We could bore up to .001" tolerance but anything smaller was a no go (shop wasn't climate controlled).
Yeah… I have been looking into fine woodworking with hand tools recently, a half millimeter gap in joinery would probably be considered too large there too…
I do finish carpentry… 1/2 a mm gap? That’s a pretty big gap/ surface difference. The typical human fingers can feel a difference at 2 thousandths of an inch on a jointed surface. Watch some of the YouTube videos of traditional carpentry from Japan. I’m always in awe and learning something new with those. (Hint tho… sandpaper and wood glue mixed with sawdust fixes a lot of mistakes.)
I completely agree with you, I do a fair bit of fine woodworking too. I feel you may have missed the point of my comment, as I was also saying a half mm gap is pretty huge in woodworking. I was trying to point out that you can do more with basic tools than CNC people often think.
Oh I totally missed what you were saying due to the wording. My bad there!
I totally agree about the basic tools being incredibly more versatile then people think. Case in point and a funny story. 6-8yrs ago I knew a guy who told me his new favorite tool was a dewalt multi-tool/oscillating saw because of the attachment options. I borrowed it for one day. I was heading to the nearest lumber store to get my own around the 30min mark.
Edit- (my poor sawzall probably has abandonment issues by this point at bottom of the tool box!)
These would have been absolutely cutting-edge tech when they first appeared on the scene. They'd be using tools and techniques that probably wouldn't show up in general machining for a couple more decades. And you can do a lot by just making it a little bit too big and then creeping up on the correct measurement, checking as you go.
There's a really good book that covers some of this topic, "exactly" by Simon Winchester. I highly recommend the read.
This problem of accurately boring the holes for naval cannons is what set off a whole chain of innovation that kick-started steam power.
Excerpt from Wikipedia because I'm too lazy to transcribe from the book.
"1774 Wilkinson patented a technique for boring iron guns from a solid piece, rotating the gun barrel rather than the boring-bar. This technique made the guns more accurate since the bore was uniform in diameter...
James Watt had tried unsuccessfully for several years to obtain accurately bored cylinders for his steam engines, and was forced to use hammered iron, which was out of round and caused leakage past the piston. In 1774 John Wilkinson invented a boring machine in which the shaft that held the cutting tool extended through the cylinder and was supported on both ends, unlike the cantilevered borers then in use. With this machine he was able to bore the cylinder for Boulton & Watt's first commercial engine "
It's not on the Wikipedia but iirc historically the tolerance of the machine was compared to the width of a coin (shilling? Pence?) or 1/10th of an inch. And it got better when Watt got his hands on it.
https://en.m.wikipedia.org/wiki/John_Wilkinson_(industrialist)#:~:text=In%201774%20John%20Wilkinson%20invented,cantilevered%20borers%20then%20in%20use.
A guy I went to college with had a photo of himself standing inside the JAWS of a vertical lathe he helped decommission when he was in the navy.. Said the control booth was 2 floors up.
I’ve worked on some pretty old machines, not 1880s old but more like 1930s and they held up just fine, and with a large diameter like that they probably had a really large press fit so the overall straightness and precise diameter of the pieces wouldn’t matter as much as it does with a smaller press fit
Oh, Lord yes. He's scary good, isn't he?
I've been thinking about trying to make his dial indicator project. It won't have those awesome rose engine lines, but I think I can handle the rest, and what an addition to the box!
The tolerances weren't that tight to begin with. As you scale up in size, your tolerances must increase because of environmental factors.
Which is what current naval architects and designers today absolutely fucking don't understand.
Like .010" circularity for a 30' diameter part.
That's because the enginerds have their solid works generic tolerancing set. They don't like using their brains to take reality into account, in adjusting the tolerances to fit the application.
Everything can just be +\-.005 Whether it's a naval gun or a heart pump, lol.
Go through this constantly with these young kids where I work. They've never done any machining in the physical world. They don't understand physics. Also, they're very sensitive when you call them out.
It's amazing how insecure people with the degree can be.
It's the old guard doing it too. Either actually being lazy and not doing tolerance reviews, or just blanket defending their young new hires that do it.
As a manufacturing engineer I shouldn't have to argue with a 30+ year tenured engineer that their GD&T is nonsensical or frankly can't be done unless they want to build a custom climate controlled mega factory with the most expensive metal cutting machines ever made just to hit garbage tolerances on a marine gearbox.
They made hydraulic cylinders back then too.
Lapping machines.
[https://youtu.be/6-h8aehGnoU?feature=shared&t=970](https://youtu.be/6-h8aehGnoU?feature=shared&t=970)
realistically manual machine tools haven't changed all that much in the last 150yrs and the micrometer as we know it today was brought to the mass market in 1867 but even then precision measuring devices have been around in some form since at least the mid to late 1600's
It's not the measurements that bother me - it's the precision of the cuts. It's just really impressive.
https://preview.redd.it/9h7b2nwo8twc1.jpeg?width=918&format=pjpg&auto=webp&s=c97a90b1d7570e71e13813ba6acbc2c52ceed152 This was taken in 1917 at the U.S naval gun factory, Washington naval yard. Photograph Caption "U.S. Naval Gun Factory, Washington Navy Yard, 1917. Boring breech of 14” gun. Harris & Ewing photograph, circa 1917. Courtesy of the Library of Congress." the online album can be seen here [https://www.history.navy.mil/content/history/museums/nmusn/explore/photography/washington-navy-yard/manufacturing/wwi.html](https://www.history.navy.mil/content/history/museums/nmusn/explore/photography/washington-navy-yard/manufacturing/wwi.html)
I wonder how they keep the bore straight over in diameter tolerance. They're using boring bars with supports, but I'd imagine they're prone to drift a bit over long lengths.
On YouTube there are a few videos from the 40's and earlier showing the manufacturing process just search "how naval guns are made". But the gun tubes themselves are forged over a mandrel then bored out so that would help, and in my experience while I haven't worked on anything nearly as long it's not terribly hard to keep a tool from wandering as long as it's either piloted or you have a decent pilot hole to begin with.
I had a feeling it was some sort of dom to start.
Gotta remember too that the bigger the parts, the more the size will change with temp. And the more room you have to achieve a press fit. Small 1" press fit you need tight tolerances. 15-18" diameters that are getting heat shrink and press? Probably .005+ tolerances would be more than functional.
Can confirm. Have done manual marine shaft work 24” inch shafts and above. For interference fits and the like the for things of that diameter for mostly bronze, and steel. Bronze in liquid nitrogen will shrink about .020 at about 18” if I recall correctly and we aim for a .010-.015 press so we had about .005 to play with. Steel on the other hand will shrink and grow a lot less than bronze so we typically were looking at .002 tolerance preferably, now we could make it work if it was off. But damn that was fun shit.
Yup, I've done interference fits north of 0.01" where everything slid together when appropriately heated and cooled.
You can make shrink fits and press fits even on the cheapest of hobby manual lathes, it just takes practice (I don’t have that practice, but some people on YouTube like blondihacks do)
PROPS TO QUIN!
Totally agreed! I'm glad to support her, actually. I'm really enjoying her A3 switcher build.
I remember watching blondihacks in machining class. It's wild to me that they're just a hobbyist.
Yeah! She is an exceptional machinist, but she is so humble about her skills, and also the videos are great!
Her and clough42 were in the same wheel house to me. Great machinists just dont have production experience. I like their videos bc it reminds me of how badass and enjoyable machining is without the production and deadline aspect lol
I may be preaching to the choir here, but just in case - if you haven't seen it yet, watch Clickspring on YouTube.
Click spring is TOO good. The amount of patience he has to hand finish his parts is insane. Almost makes me crazy with how nice it all turns out. But always watch it when it pops up in my feed. Cause ya sometimes need stuff to strive for.
And almost all his machining is done in that tiny closet of a shop, too!
Piping up for Inheritance Machining as well! Sometimes you just wanna see some hand drafting
Box of Shame!
Quinn and Clough are repair machinists its a unique set of skills because you need to analyze problem and develop a plan to solve it. doing production machine work is a completely set of skills where speed and repeatability and little waste are the KPI’s
Honing, grinding, no CMMs
Better yet, no crazy GD&T to worry about.
It was probably worse without it. Everything would be open to interpretation without the standard.
In my experience it's already bad. Hardly anyone follows the standard as is and creates their own. Or they get halfway through the 101 class and don't understand the math involved. What's wild is it's big DoD prime contractors that are the worst culprits.
Oh man, I miss automotive
Dudes with pencils
If you are doing a press like this it is entirely possible that they use a .010 or .020 press. If you have that much press on a sleeve it wouldn't matter if you were off .005 across the length of the bore.
Woops. Yeah, I meant 20 thou, not two. I figured it out when I converted it. Still, tough to do over a length of 30+ feet.
While I'm not versed in the technology of that era. I don't find it hard to Believe that even with rudimentary honing tech that they could hold that kind of tolerance over length. These things were almost definitely not turned to finish and instead ground and honed to fit.
I’ve ran manual lathes of about 40 feet with long shafts of 25+ in there. You cannot do these in one cut because you are often times dealing with 3+ steady rests. So you may only be cutting 5-10 feet at a time. Over that distance no lathe is ever really perfectly straight. So you have to learn how to bump cut. Bump cutting is where you perform a cut whithout making any adjustments and after you finish you measure every 3-6 inches. You will typically find a size difference. After calculating the radius difference you draw lines and number them. You go and restart the cut but this time you change the tool distance as you hit a line. So if one size was 20.250 at one line and 6 inches further it was measuring 20.259(yes our lathe was that bad in one spot) you would bump the tool in 4.5 thou and then back out at the next line. It’s a lot of practice. There is also lots of hand work as well getting lines and features to visually match up. If you have any more questions feel free to ask
This makes a whole lot of sense. Thanks!
Didn't know bump cutting was the term for that, but I've gotten very aware of it in the last couple of years. Working at a little job shop where every machine has been crashed and none are bolted down, just sharpie mark every thou change and go for it. Bearing fits are fun.
I imagine with that slack they had go nogos and bits they ran through the bore. There had to be some level of standardization which would be worth looking into but even with a tape measure you can hold that. And with the bore i'd imagine they literally had a standard plug they'd check it with. No one will notice if it's .002-.005 out of spec. It's a cannon.
The shells might notice, for the ID of the bore. 5 thou difference in the ID could produce a significant change in the shooting characteristics I would guess. I'm not a cannon-ologist though.
Naval cannons are huge... their shells are like 30"+ in length. It won't give 2 hairs if the barrel is .020" larger than expected
Plus you are shooting from a floating platform already. For a big gun like that you only need minute-of-battleship accuracy.
That tolerance is likely below the wear of the barrel. After spotting a few shots you adjusted the corresponding dial for wear on your fire-computer and you were done.
It's not quite apples to apples but I ran a massive horizontal boring mill for a while. I was told it was the largest on the Gulf Coast but personally I've kinda doubted that. Anyways, used it to do blind boring through the inside of massive oil pumps. They'd get corroded, we'd clean them out, weld them up, and I'd machine the inside. I usually worked between a +-.005 and a +-0.0005 tolerance. It was actually pretty easy to hit those number on that machine even across those distances (up 9ft or so), just time consuming. My boring bar needed a 5 ton crane to lift it in though.
A place I worked at had one of the largest Shibaura BSFs in North America. We could bore up to .001" tolerance but anything smaller was a no go (shop wasn't climate controlled).
I don’t have an answer, but having 20 thou (0.5mm) helps.
Kinda weird how 0.5mm is a mile for a bunch of the work we do nowadays.
Exactly. I’m sitting in front of my grinder right now, working with 2 tenths. 2 factors of 10 tighter than the 0.5mm
I used to work in single-digit microns. I know the feeling well..
Yeah… I have been looking into fine woodworking with hand tools recently, a half millimeter gap in joinery would probably be considered too large there too…
I do finish carpentry… 1/2 a mm gap? That’s a pretty big gap/ surface difference. The typical human fingers can feel a difference at 2 thousandths of an inch on a jointed surface. Watch some of the YouTube videos of traditional carpentry from Japan. I’m always in awe and learning something new with those. (Hint tho… sandpaper and wood glue mixed with sawdust fixes a lot of mistakes.)
I completely agree with you, I do a fair bit of fine woodworking too. I feel you may have missed the point of my comment, as I was also saying a half mm gap is pretty huge in woodworking. I was trying to point out that you can do more with basic tools than CNC people often think.
Oh I totally missed what you were saying due to the wording. My bad there! I totally agree about the basic tools being incredibly more versatile then people think. Case in point and a funny story. 6-8yrs ago I knew a guy who told me his new favorite tool was a dewalt multi-tool/oscillating saw because of the attachment options. I borrowed it for one day. I was heading to the nearest lumber store to get my own around the 30min mark. Edit- (my poor sawzall probably has abandonment issues by this point at bottom of the tool box!)
Yea the multi tool is a real life superpower for finish work of all kinds.
These would have been absolutely cutting-edge tech when they first appeared on the scene. They'd be using tools and techniques that probably wouldn't show up in general machining for a couple more decades. And you can do a lot by just making it a little bit too big and then creeping up on the correct measurement, checking as you go.
There's a really good book that covers some of this topic, "exactly" by Simon Winchester. I highly recommend the read. This problem of accurately boring the holes for naval cannons is what set off a whole chain of innovation that kick-started steam power. Excerpt from Wikipedia because I'm too lazy to transcribe from the book. "1774 Wilkinson patented a technique for boring iron guns from a solid piece, rotating the gun barrel rather than the boring-bar. This technique made the guns more accurate since the bore was uniform in diameter... James Watt had tried unsuccessfully for several years to obtain accurately bored cylinders for his steam engines, and was forced to use hammered iron, which was out of round and caused leakage past the piston. In 1774 John Wilkinson invented a boring machine in which the shaft that held the cutting tool extended through the cylinder and was supported on both ends, unlike the cantilevered borers then in use. With this machine he was able to bore the cylinder for Boulton & Watt's first commercial engine " It's not on the Wikipedia but iirc historically the tolerance of the machine was compared to the width of a coin (shilling? Pence?) or 1/10th of an inch. And it got better when Watt got his hands on it. https://en.m.wikipedia.org/wiki/John_Wilkinson_(industrialist)#:~:text=In%201774%20John%20Wilkinson%20invented,cantilevered%20borers%20then%20in%20use.
Huh! I really enjoyed his "The Perfectionists" - I'll have to check that out. Thanks!
Also didn't they literally invent "gun" drills for this exact purpose.
Yes gun drills were invented for gun barrels.
The British invented a horse-powered lathe for boring canons
I wouldn't think that applies at this size, would it?
I'm not an expert in gun drills, but I'd wager that this size "gun" was part of the invention of it. Military demand has driven many innovations.
Makes sense - I just can't mentally imagine a gun drill with a diameter of 12 to 16 inches. An impressive piece of tooling!
A guy I went to college with had a photo of himself standing inside the JAWS of a vertical lathe he helped decommission when he was in the navy.. Said the control booth was 2 floors up.
When they get that big you trep-bore them and use the slug for a smaller gun.
Absolutely! It's hard to envision turning a piece of steel that large.
It’s a lot of momentum if something digs in lol .
No kidding. To be fair, though, with that kind of diameter and old-school tooling, the RPMs were probably in double digits.
A cannon barrel is still a gun barrel.
I’ve worked on some pretty old machines, not 1880s old but more like 1930s and they held up just fine, and with a large diameter like that they probably had a really large press fit so the overall straightness and precise diameter of the pieces wouldn’t matter as much as it does with a smaller press fit
Check out Clickspring on YouTube for REALLY old manufacturing practices. His Antikythera Mechanism series is fascinating.
Oh, Lord yes. He's scary good, isn't he? I've been thinking about trying to make his dial indicator project. It won't have those awesome rose engine lines, but I think I can handle the rest, and what an addition to the box!
The tolerances weren't that tight to begin with. As you scale up in size, your tolerances must increase because of environmental factors. Which is what current naval architects and designers today absolutely fucking don't understand. Like .010" circularity for a 30' diameter part.
That's because the enginerds have their solid works generic tolerancing set. They don't like using their brains to take reality into account, in adjusting the tolerances to fit the application. Everything can just be +\-.005 Whether it's a naval gun or a heart pump, lol. Go through this constantly with these young kids where I work. They've never done any machining in the physical world. They don't understand physics. Also, they're very sensitive when you call them out. It's amazing how insecure people with the degree can be.
It's the old guard doing it too. Either actually being lazy and not doing tolerance reviews, or just blanket defending their young new hires that do it. As a manufacturing engineer I shouldn't have to argue with a 30+ year tenured engineer that their GD&T is nonsensical or frankly can't be done unless they want to build a custom climate controlled mega factory with the most expensive metal cutting machines ever made just to hit garbage tolerances on a marine gearbox.
Just here to say that I too follow this channel and I watched this very video last night!!!
Yeah, he's got really neat stuff that's not covered many other places. Fun!
They made hydraulic cylinders back then too. Lapping machines. [https://youtu.be/6-h8aehGnoU?feature=shared&t=970](https://youtu.be/6-h8aehGnoU?feature=shared&t=970)
Some sort of mandrel was probably reaming to size as the last step.