manufacturing Production Discussion

[tastethecake]

Found this instructional manual on screw machine (think of it as all mechanical CNC machine that takes forever to tool up) setup, and it got me thinking about how much of a lost art running one of these things is. CNC lathes and machines in general are obviously much easier to set up but they still cannot match the potential of a multiple spindle screw machine that can spit out parts like nobody's business (they can come quite close however). 

Another topic of conversation that fascinates me is the concept of the multiple spindle milling machine, at first glance it seems like an inelegant solution to the problem of increasing mill production, but that's just me. Does anyone have any idea if form tools were ever used to cut the outer profile of parts in one pass on these machines? 

Perhaps I am looking at this from the wrong way however,  once production becomes so important that you need to improve the output of a screw machine, it might be best to look at other options (die casting, stamping, etc.).

One last note, I wanted to see what people think of stamping sheet metal gears. Is this just a novelty thing someone does for their CAD portfolio or something actually viable?

More sources below...
How many spindles are really necessary?
Running a multiple spindle machine in a small part run world

Edited March 22, 2020 by tastethecake
added more sources

[Sturgeon]

Ever wonder how they milled intricate guns like the Browning BAR, Hi-Power, or Roth-Krnka-Steyr 1908? They used horizontal mills (which were originally just "mills" btw, because they looked like watermills). Horizontal mills have a large relatively slow spinning bit with a wide maximum diameter (the ones I've used were like 18-24" diameter and spun at circa 500 RPM). Often they are very deep as well, even 8" plus in depth. The bit itself is tooled to create the negative of any linear surface. You could mill out the profile of a Honda Accord in one pass, if you had the right bit. You could also use a horizontal mill along with a rotary table to mill that shape along a curve, or a complex curve. These were the height of sophisticated manual (!) tooling, in my opinion. The big downside is that they are highly specialized, you can do one operation per (very expensive) horizontal milling tool. Nothing else. But many of the best looking production firearms, which now are considered far too expensive to make, were made this way, with chains of horizontal mills carving out one profile at a time.

[Sturgeon]

Remember how in his video on the Roth-Krnka-Steyr, Ian marvels at how expensive they must have been to make because of the intricate milling?

 

 

That's because bitches don't know bout my horizontal mills.

[tastethecake]

5 hours ago, Sturgeon said:

These were the height of sophisticated manual (!) tooling, in my opinion. The big downside is that they are highly specialized, you can do one operation per (very expensive) horizontal milling tool. Nothing else.

Makes me wonder what the plan is to utilize old iron like that today in a wartime scenario.

Found this 1 hour video and I think it would be really eye opening for anyone designing anything. Each little feature of that doohickey you drew up in cad? Yeah, someone has to machine it. Which is obvious but I think it gets overlooked far too often.

[Sturgeon]

18 minutes ago, tastethecake said:

Each little feature of that doohickey you drew up in cad? Yeah, someone has to machine it. Which is obvious but I think it gets overlooked far too often.

 

Not by any engineer who's actually working, it isn't.

[Sturgeon]

Who that video is most enlightening to I think would be generalist historians and people coming from an art background. Not "anyone designing anything". Most people who design things are in some kind of workflow where the things they design are getting made (you typically can't get paid otherwise). And frankly, anyone with literally only as much formal engineering education as I have (~1 yr) should absolutely know better.

[tastethecake]

11 minutes ago, Sturgeon said:

 

Not by any engineer who's actually working, it isn't.

Optimally, yeah, but this kind of thing can happen even to good engineers. 

I remember one time where an engineer in charge of fixtures got WAY task saturated and ended up designing a fixture that held a part on a contour instead of just on the base of the part to simplify his workload. Peacetime production is different then wartime production like that, you have to weigh the cost of the time the engineer spends designing an easy to make and effective fixture versus something you can design in an hour with some crazy 3D contour and have some local CNC shop make for you in 1 week.

[tastethecake]

4 minutes ago, Sturgeon said:

Who that video is most enlightening to I think would be generalist historians and people coming from an art background. Not "anyone designing anything". Most people who design things are in some kind of workflow where the things they design are getting made (you typically can't get paid otherwise). And frankly, anyone with literally only as much formal engineering education as I have (~1 yr) should absolutely know better.

You make a good point though, I think I probably overstated the "enlightenment factor" of that video.

[Sturgeon]

1 minute ago, tastethecake said:

Optimally, yeah, but this kind of thing can happen even to good engineers. 

I remember one time where an engineer in charge of fixtures got WAY task saturated and ended up designing a fixture that held a part on a contour instead of just on the base of the part to simplify his workload. Peacetime production is different then wartime production like that, you have to weigh the cost of the time the engineer spends designing an easy to make and effective fixture versus something you can design in an hour with some crazy 3D contour and have some local CNC shop make for you in 1 week.

 

That's a bit of a goal post shift. An engineer making a mistake does not equal him entirely forgetting the concept that what he's working on has to be produced in the end.

[Sturgeon]

11 minutes ago, tastethecake said:

You make a good point though, I think I probably overstated the "enlightenment factor" of that video.

 

To the right people, it's probably very enlightening. But production basics are a part of any engineering education (including informal ones) that is worth calling it that. If you are just doing CAD all day with no concern for the object actually being made, you're either an artist using off-kilter software, or you work for a VERY strange company.

 

All of my rifle designs, for example, were production engineered (to an extent) despite the fact that I knew when I started they would never get made outside of 3D printed mockups.

[tastethecake]

2 minutes ago, Sturgeon said:

All of my rifle designs, for example, were production engineered despite the fact that I knew when I started they would never get made outside of 3D printed mockups.

Mind sharing them? 
 

 

6 minutes ago, Sturgeon said:

 

That's a bit of a goal post shift. An engineer making a mistake does not equal him entirely forgetting the concept that what he's working on has to be produced in the end.

There goes my inner /k/ommando revealing itself again I suppose. Yes, that is a goal post shift. You are right when you say engineers that are actually employable have to keep production in mind. Sometimes that can be hard to see from a machinist's perspective but it is absolutely true.

[Sturgeon]

38 minutes ago, tastethecake said:

Mind sharing them? 

 

Fucking zoomers, man.

[tastethecake]

1 hour ago, Sturgeon said:

 

Fucking zoomers, man.

Don't expect me to hold you protecting your own intellectual property against you.

Edited March 24, 2020 by tastethecake
grammar

[Sturgeon]

1 hour ago, tastethecake said:

Don't expect me to hold you protecting your own intellectual property against you.

 

I don't think you meant it, but it came off as "cough it up". Very entitled sounding. You could have searched the forum, checked the small arms section, checked my various haunts (there's a bit about them on my Twitter, even), googled it, or even asked me a little more nicely.

 

I know what you meant. But abbreviating "pardon me for asking, but are you willing to share them? I'm very interested." comes off a lot more differently than "mind sharing?" One is pretty definitively polite, the other isn't.

[tastethecake]

2 minutes ago, Sturgeon said:

 

I don't think you meant it, but it came off as "cough it up". Very entitled sounding. You could have searched the forum, checked the small arms section, checked my various haunts (there's a bit about them on my Twitter, even), googled it, or even asked me a little more nicely.

 

I know what you meant. But abbreviating "pardon me for asking, but are you willing to share them? I'm very interested." comes off a lot more differently than "mind sharing?" One is pretty definitively polite, the other isn't.

Thanks for letting me know. I have to try to improve my "internet etiquette" in the future, its been a frequent failing of mine. That and pushing the enter key instead of the period key in DM's.

[RD2755]

On 3/22/2020 at 10:02 AM, tastethecake said:

One last note, I wanted to see what people think of stamping sheet metal gears. Is this just a novelty thing someone does for their CAD portfolio or something actually viable?

Chauncey Jerome invented a method of making clock gears in 1837 by stamping them out of sheets of brass, so it was done in the past.  But today, most gears seem to be made from stronger methods like extrusion or forging.  Those methods also don't produce as much scrap metal as stamping (though stamping still wastes less material than milling most of the time).  There are in particular a lot of documents about this related to the US Army in the 1970's, '80s, and '90s.  They mainly wanted to mass-produce cheaper and stronger gears for tanks and helicopters.  The documents are about the die design and computer programs to calculate its dimensions:

SPIRAL BEVEL GEAR AND PINION FORGING DEVELOPMENT PROGRAM- February 29, 1972

Precision Forged Spiral Bevel Gears- CAD/CAM Technique Makes It Practical- August/September 1984

Manufacturing of Forged and Extruded Gears- July/August 1990

 

I also read about thread rolling machines like this planetary thread roller (the fastest kind there is), or the other three kinds: 2-die, 3-die, and flat.  They are covered here, or Wikipedia has a diagram of each type of rolling.  In theory, gears could be made the same way (now that I think about it, threaded bolts are technically a very heavily angled helical gear), with a gear-shaped die rolling the blank into a gearwheel.

 

On 3/24/2020 at 2:35 AM, Sturgeon said:

Ever wonder how they milled intricate guns like the Browning BAR, Hi-Power, or Roth-Krnka-Steyr 1908?

For the Lewis Gun and some other WWI weapons, I don't have to wonder:

Compilation of sources from WWI-era American Machinist volumes (includes Welin breech manufacturing)

Spoiler

First, a general link to the Hathitrust page with links to their American Machinist volumes during this era (Volumes 19, 20, 24, and 29-58):

https://catalog.hathitrust.org/Record/008896977

And then going in chronological order, the specific volumes where my sources are:

 

American Machinist Volume 45 (late 1916):

• https://www.google.com/books/edition/_/7uk-AQAAMAAJ
• https://archive.org/details/americanmachinis45newyuoft/page/n3/mode/2up

Articles in this volume:

• Manufacturing the 1-Lb High Explosive Shell by Robert Mawson, Part I p. 157-162, Part II p. 199-203, Part III p. 233-236
• Making the British Time Fuse Mark 80-44-I by Fred H. Colvin, Part I p. 367-374, Part II p. 421-425
• Operations on the British 12-In. Mark IV Howitzer Shell Special Correspondence, p. 485-489
• Varnishing Shells by W. H. Watson (specifically British 4.5-In. Ones), p. 510-511
• Polishing Lathe for Shells by John S. Watts, p. 532-533

 

American Machinist Volume 46 (early 1917):

• https://www.google.com/books/edition/_/p98-AQAAMAAJ (second half only from page 573)
• https://www.google.com/books/edition/_/1nMfAQAAMAAJ
• https://archive.org/details/americanmachinis46newyuoft/page/n4/mode/2up

Articles in this volume:

• United States Common Shrapnel and Common Steel Shells, 3.8, 4.7, and 6 In. manufacturing specifications, p. 1113-1118
• United States Munitions 3-In. Common Shrapnel Shell manufacturing specifications, p. 353-377
• United States Munitions 3-In. Common Steel Shell manufacturing specifications, p. 486-507
• United States Munitions 3 to 6 In. Cartridge Cases manufacturing specifications, p. 881-903
• Three-Inch United States Navy Projectiles by Lieut. A. G. Dibrell, p. 969-976
• Handling 8-In. Shell Forgings by M. E. Hoag, p. 1101-1105

And one article so large it gets its own list:

United States Munitions The Springfield Model 1913 Service Rifle manufacturing specifications:

• Sleeve Operations, Part II, p. 19-27
• Cocking Piece, p. 69-76
• Striker, Mainspring, Extractor, Extractor Collar, Ejector, Ejector Pin, Part I p. 111-119, Part II p. 153-161
• Safety-Lock Spindle, Plunger, p. 245-250
• Guard, Sear, Trigger, Floor Plate, Floor-Plate Catch, Magazine Spring, Cutoff, Follower, Part I p. 287-294, Part II p. 333-338, Part III p. 551-558, Part IV p. 415-426
• Movable Stud, Front Sight, Movable Base, Leaf, Slide, Cap, Part I p. 463-469, Part II p. 595-602, Part III p. 641-647
• Drift Slides, Windage Screw, Butt Plate, Butt-Plate Cap, Upper Band, Lower Band, Spring and Swivel, Butt Plate Swivel, Part I p. 685-690, Part II p. 729-735, Part III p. 771-779
• Stacking Swivel, Hand-Guard Clip, Front-Sight Cover, Cleaning Rods, p. 817-823
• Oiler and Thong Case, Spare Parts Kit,Screwdriver, p. 947-953
• Making the Stock, Part I p. 1031-1041, Part II p. 1079-1085, Part III p. 1123-1129

 

American Machinist Volume 47 (late 1917):

• https://www.google.com/books/edition/_/snQfAQAAMAAJ
• https://archive.org/details/americanmachinis47newyuoft/page/n4/mode/2up

Articles in this volume:

• The Manufacture of the Lewis Machine Gun by Frank A. Stanley (at Savage Arms Corporation, continues in Volume 48), Part I p. 969-971
• Building Carriages, Caissons and Limbers for 75-mm. Guns by M. E. Hoag (continues in Volume 48), Part I p. 793-796, Part II p. 861-865, Part III p. 901-904

 

American Machinist Volume 48 (early 1918):

• https://www.google.com/books/edition/_/iIJrybK2TuEC (Early March 1918)
• https://www.google.com/books/edition/_/S4fVOLSW3r8C (Early June 1918)
• https://www.google.com/books/edition/_/4SK2tFaZ9-cC (Late April 1918)
• https://www.google.com/books/edition/_/VcrM35zcj8AC (February 1918)
• https://www.google.com/books/edition/_/pe-MYk7fUF4C (Early April 1918)
• https://www.google.com/books/edition/_/BNnuOUJYAr8C (Late June 1918)
• https://www.google.com/books/edition/_/PKSVtYj6brcC (Late March 1918)
• https://www.google.com/books/edition/_/RVpOta5lWdQC (June 20^th 1918 only)
• https://www.google.com/books/edition/_/n2dBAQAAMAAJ (entire 1^st half of 1918, but only from page 561 onwards)
• https://www.google.com/books/edition/_/G-A-AQAAMAAJ (January-March 1918)
• https://www.google.com/books/edition/_/t7pMAQAAIAAJ?hl=en (January-March 1918, p.1-566)
• https://archive.org/details/americanmachinis48newyuoft/page/n4/mode/2up

Articles in this volume:

• Manufacture of the 4.7-Inch Gun Model 1906 by E. A. Suverkrop, Part I p. 519-524, Part II p. 649-658
• The Manufacture of the Lewis Machine Gun by Frank A. Stanley (at Savage Arms Corporation, continued from Volume 47, continues in Volume 49), Part II p. 265-273 (February 14), Part III p. 397-403, Part IV p. 579-584, Part V p. 663-667, Part VI p. 747-752, Part VII p. 825-828, Part VIII p. 873-878, Part IX p. 949-952
• Manufacture of the 75-mm. High-Explosive Shell by S. A. Hand, Part I p. 435-439, Part II p. 535-539, Part III p. 705-712
• Building Carriages, Caissons and Limbers for 75-mm Guns by W. J. Larson (continued from Volume 47), Part IV p. 229-231, Part V p. 277-279
• Hydraulically Operated Shell Production Machinery by I. William Chubb, p. 939-943
• Making 50,000 French 75-mm. Shrapnel per Day by Robert K. Tomlin Jr (specifically about Citroën), p. 987-990
• Manufacturing Base Plugs for the 80 Mark VIII Time Fuse by John Campbell, p. 414-417
• The Relining of Guns at Watervliet Arsenal by E. A. Suverkrop, Part I p. 687-691, Part II p. 783-785, Part III p. 859-862
• Boring and Reaming Tools for 220- and 270-mm. French Shells by James Forrest, p. 70-72
• Self-Centering Driver for Rough-Turning Shells by H. A. Wilson, p. 427
• Making Concrete Metal-Planing Machines by Ethan Viall (for planing beds for further gun-boring lathes), p. 603-608

 

American Machinist Volume 49 (late 1918):

• https://www.google.com/books/edition/_/28Ms4FAP-fEC (July-Early September 1918)
• https://www.google.com/books/edition/_/j2FBAQAAMAAJ (October-December 1918)
• https://babel.hathitrust.org/cgi/pt?id=njp.32101048995243&view=1up&seq=14

Articles in this volume:

• Manufacture of the Lewis Machine Gun by Frank A. Stanley (at Savage Arms Corporation, continued from Volume 48, continues in Volume 50), Part X p. 25-29, Part XI p. 203-207, Part XII p. 481-484, Part XIII p. 529-531
• The British 6-In. Howitzer by I. William Chubb, Part I p. 231-242, Part II p. 411-423, Part III p. 605-612, Part IV p. 697-704
• How the 155-Mm. Howitzer is Made by J. V. Hunter (specifically about the 155 M1918 made at American Brake Shoe and Foundry, continues in Volume 50), Part I p. 941-945, Part II p. 983-986, Part III p. 1123-1129
• The Development of the French 75-mm. Field Gun by J. A. Lucas, p. 149-152
• Lathes for the Present Gun Program by A. L. de Leeuw, p. 491-493
• The 75-mm Field Gun Model 1916, M.III Special Correspondence, p. 323-328
• The Three-Inch Anti-Aircraft Gun, Model 1918 Special Correspondence, p. 185-190
• The Engineering Division of the Ordnance Department by John H. Wan Deventer (about design and transport of weapons in general in the WWI US Army), p. 921-931
• What Ordnance Is and Does by John H. Van Deventer (mainly useful as the only photo I have of an 8-inch US pre-WWI howitzer on p. 876), p. 875-881
• Chilled Cast-Iron Dies for Forging and Nosing Shells by A. F. White, p. 747-748
• Slotting Breech Bushings by H. W. Merrill, p. 1186
• Making Boring Bars for Big Guns by M. E. Hoag, p. 987-988
• Tool for Burring Inside of Dummy Cartridge Shells, p. 1048-1049
• Making a Spiral Rack for the Sights on the Six-Pound Gun Mounts by Severin Seaberg, p. 470
• Polishing Inside Profile of Nose on High-Explosive Shells by H. A. Wilson, p. 168
• Some Types of Modern Grenades by Rudolph C. Lang, p. 139-143
• Grinding 6-In. Shell-Boring Cutters by George M. Dick, p. 207-208

 

American Machinist Volume 50 (early 1919):

• https://www.google.com/books/edition/_/P-49AQAAMAAJ?gbpv=0
• https://www.google.com/books/edition/_/9OU-AQAAMAAJ
• https://www.google.com/books/edition/_/BmJBAQAAMAAJ (1^st half only up to page 624)
• https://www.google.com/books/edition/_/SK1LAQAAIAAJ (2^nd half only from page 605)
• https://www.google.com/books/edition/_/g6xLAQAAIAAJ (1^st half only up to page 624)
• https://archive.org/details/americanmachinis50newyuoft/page/n4/mode/2up

Articles in this volume:

• Manufacture of the Lewis Machine Gun by Frank A. Stanley (at Savage Arms Corporation, continued from Volume 49), Part XIV p. 55-60
• How the 155-Mm. Howitzer is Made by J. V. Hunter (specifically about the 155 M1918 made at American Brake Shoe and Foundry, continued from Volume 49), Part IV p. 199-204, Part V p. 249-252, Part VI p. 303-306, Part VII p. 587-593, later acknowledgement that Schneider actually designed it and the 240-mm howitzer (apparently no one mentioned this in the main article) p. 908
• The British 8-In. Howitzer by I. William Chubb (continues in Volume 51), Part I p. 1189-1194
• Manufacturing the 9.2-In. Howitzer Shell by S. A. Hand, Part I p. 799-801 and 839-842, Part II p. 895-897 and 947-950, Part III p. 1089-1093
• Cam Rails Used in Planing Howitzer Jackets by E. A. Thanton, p. 230
• Unique Shell-Profile Turning Attachment by Donald A. Baker, p. 161-162
• 155 mm Howitzer Production (about American Brake Shoe and Foundry production of 155 mm M1918 howitzers), p. 162
• How Ordnance is Inspected by Fred H. Colvin, Part I p. 263-267, Part II p. 311-316, Part III p. 557-563
• Modern Artillery Ammunition by H. M. Brayton (continues in Volume 52), Part I p. 707-710
• Finding the Cost of Ordnance by Lieut. L. S. Gatter (mainly including a 6-inch shell inspection as an example), p. 657-660
• Railway Gun Mounts by Lieut. Col. G. M. Barnes (mainly about US ones), p. 329-335
• The 14-In. Naval Railway Batteries by C. L. McCrea, p. 141-149
• History of the Aberdeen Ordnance Proving Ground by Major F. P. Lindh (mainly only photos of artillery pieces that are useful), Part I p. 459-461,Part II p. 509-513, Part III p. 607-611
• Gun-Boring Tools and Data by Fred H. Colvin (about the US 4-inch naval gun specifically), p. 997-999
• Hardness Tests of Gun-Barrel Steel by William Kent Shepard, p. 739-742
• How Army Ordnance Met Its Responsibilities by Brig-Gen. W. S. Peirce, p. 408-409
• Making Gun-Sights for Anti-Aircraft Guns by Fred H. Colvin (most likely about the 3-In. AA gun), p. 681-684
• High Production Tooling Methods as applied to the Machine-Gun Tripod, Model 1918 by Albert A. Dowd and Donald A. Baker (continues in Volume 51), Part I p. 1029-1036
• Radius Link Designing by Arthur R. Melloy (about turning the points of shells), p. 993
• Instruments for Hardness Tests by C. E. Clewell (about testing shells and armor), p. 93-96

 

American Machinist Volume 51 (late 1919):

• https://www.google.com/books/edition/_/cY5MAAAAYAAJ?gbpv=0
• https://www.google.com/books/edition/_/YeY-AQAAMAAJ?gbpv=0 (second half only from page 645)
• https://www.google.com/books/edition/_/MeY-AQAAMAAJ (1^st half only up to page 644)
• https://babel.hathitrust.org/cgi/pt?id=njp.32101048995185&view=1up&seq=7

Articles in this volume:

• The Field Mount for the 7-In. Navy Gun by C. L. McCrea, p. 523-527
• The British 18-Pounder Quick-Firing Gun by I. William Chubb, Part I p. 617-621, Part II p. 733-735
• The Manufacture of Artillery Range Finders by Geo H. Thomas (continues in Volume 52), Part I p. 1045-1047
• Operations on the British 9.2-In. Gun by I. William Chubb, Part I p. 275-280, Part II p. 373-377, Part III p. 423-427
• The Ordnance Repair Shops at Mehun-Sur-Yevre by Maj. George S. Brady, p. 575-578
• Machining Problems Solved in Gun-Making, Editorial Correspondence (about the 4.7-inch gun, continues in Volume 52), Part I p. 949-952
• Mounts for Naval Anti-Aircraft Guns by Fred H. Colvin (about the 3-inch AA gun in US service), Part I p. 79-83, Part II p. 457-461
• The Stamets Gun-Boring Lathe by E. L. Dunn (for large-caliber guns), p. 1071-1073
• The British 8-In. Howitzer by I. William Chubb (continued from Volume 50), Part II p. 13-17, Part III p. 171-176 and p. 227-230
• High Production Tooling Methods as applied to the Machine-Gun Tripod, Model 1918 by Albert A. Dowd and Donald A. Baker (continued from Volume 50), Part II p. 401-407
• Cutting the Rotating Rack For a Breech Block by L. E. Olson (about the breech block for the 12-inch M1895 coastal artillery gun), p. 1063-1064

 

American Machinist Volume 52 (early 1920):

• https://www.google.com/books/edition/_/EY1MAAAAYAAJ?hl=en
• https://archive.org/details/americanmachinis52newyuoft/page/n4/mode/2up

Articles in this volume:

• Machining Problems Solved in Gun-Making by J. V. Hunter (about the 4.7-inch gun, continued from Volume 51), Part II p. 39-43, Part III p. 133-136, Part IV p. 613-616, Part V p. 733-735
• Broaching the Recoil Cylinder of the 4.7-In. Gun by M. E. Infiorati, p. 977-978
• The Manufacture of Artillery Range Finders by George H. Thomas (continued from Volume 51), Part II p. 249-254, Part III p. 301-304, Part IV p. 403-404
• Unusual Methods of Securing Extreme Accuracy by A. L. De Leeuw (about the Canon de 75’s recoil cylinder), Part I p. 595-599, Part II p. 937-941, Part III p. 1049-1053, Part IV p. 1094-1097
• Graduating Range Finder Sights by L. B. Rich, p. 1097-1098
• Modern Artillery Ammunition by Capt. H. M. Brayton (continued from Volume 50), Part II p. 95-101

 

American Machinist Volume 55 (Late 1921):

• https://www.google.com/books/edition/_/jrlLAQAAIAAJ?hl=en (1^st half only up to page 546)
• https://archive.org/details/americanmachinis55newyuoft/page/n4/mode/2up

Articles in this volume:

• Manufacturing with Special Machines vs. Standard Equipment by Col. G. F. Jenks and M. H. Christopherson (about the 240 mm US siege howitzer recuperator), Part I p. 37-39, Part II p. 97-101, Part III p. 228-233, Part IV p. 349-353, Part V p. 475-479

 

From that source, I can go to Volume 48, to Part IV of the Lewis Gun article on pages 581-583 (using the Internet Archive link), for example:

Gauges and jigs.

Gauges and jigs everywhere.

 

For reference on what the finished receiver of the Lewis Gun looked like, C&Rsenal's teardown has good views of most of its parts.

 

The rest of the Lewis Gun series is like this, and most of the other articles linked in the original post are like this too.  In addition Volume 52's article about the Canon de 75's recoil cylinder has been copied and reposted on that forum, with a bunch of typos corrected, images shifted around, metric values added, and links and sources about the operation and background of that recoil system:

Canon de 75 mle 1897/ US Model 1897 recoil system function and manufacturing.

I'm sure that today a 0.0008" tolerance on a 63" long lapped hole is nothing special, but in 1918 it was the biggest mass production achievement of WWI, believed impossible by the French and anyone else.