Rifling machine plans

See

for some ideas.

An interesting question, I remember when I grew up in the US in the

1970s seeing a film several times of a working museum, in Pennsylvania?,  that preserved the techniques for making long rifles, Kentucky?, and the main detail was about the rifling technique and mechanics used  It didn't look high tech just required a bit of work to produce the master screw which governed the rifling cutter.

What did you think of the CoCo?

I was very impressed with the 6809's powerful instruction set, after struggling to turn a homebrew wire-wrapped 8080 machine into something resembling the IBM PC. The 8080 lacks relative jumps and is more suited to embedded control than general purpose computing with loadable programs. It provided good training in computer hardware design, though.

The company was right at the leading edge of high speed memory chip testing so I learned a lot about transmission lines and impedance matching that helped greatly with digital radio design later at Mitre. The memory testers were so fast that there would be three test vectors (address & write data) travelling out within the coax between the machine cabinet and the test head at the wafer prober, and three results coming back. We manually trimmed the cable lengths to match their propagation delays within a few picoseconds, 16ths of an inch at the speed of light.

The CoCo had an elegantly simple video controller that I borrowed, in monochrome form, after giving up on Don Lancaster's Cheap Video.

Although I didn't use the 6809, studying it helped a lot when I had to design a 16-bit A/D converter board to go in a 68000-based NuBus Macintosh and the Apple Certified Programmer assigned to write its driver quit.

I could program UVPROMs on the Automatic Test Equipment we were building at work, I wrote a routine to do it quickly for practice, but the engineers gave me slow, pre-production samples of 2816 flash memory that's pin-compatible with the 2716 UV PROM, and the 6116 CMOS static RAM I was using.

The slow, tedious, manual method of gun making prompted several early inventors to create automation.

Until around 1850 military contracts provided the only advance financing and guaranteed demand to support buying new production machinery. Combined with chronic labor shortages as immigrants headed for the frontier, government rifle purchases were the first driver for America's rapid advances in industrial automation. In 1800 we were a backward third world nation, by the 1850's we were selling world-class rifle production machines to Britain.

Or you sure that wasn't OS-9? The one by Microware which made the MC-6809 into a multi-user multi-tasking system (if you has additional serial ports.)

I used it (along with DOS-69 on a SWTP 6809 system, after using the MC-6800 on both an Altair 680b and a SWTP 6800. The latter made it easier to wire-wrap custom interfaces -- and mechanically/electrically compatible with the SWTP 6809).

I preferred OS-9, once I had it, but started with SSB'sj DOS-68 and DOS-69 for the 6809 system.

They got a lot out of very little hardware. But the bit-banger serial interface was terrible -- toss in some MC-6850 serial port chips and it got a lot more usable for multi-user operation.

the MC-6800 was pretty good already, but Motorola did the right thing with the MC-6809, tossing away backward compatibility -- though they made an assembler which could convert MC-6800 code to MC-6809 code, as long as you stayed clear of things playing with analyzing the stack, as the monitor (EP)ROM did. They (SSB) had a really nice later monitor EPROM -- while the SWTP 6800 used Motorola's MIKBUG as the monitor ROM, and tricky addressing for the early SSB floppy controller card EPROMs to allow it to be interleaved with the I/O address space.

That controller was another custom Motorola chip, IIRC.

I did a lot of assembly language work with the 6800 and 6809. Very little with the 68000, where most of my examples were Sun workstations and servers, with good C compilers. The first system was a COSMOS CMS-16/UNX with v7 unix and a terrible C compiler. Later system were the AT&T Unix-PC/7300/3B1 using the MC-68010 CPU, and the later Suns (before SPARC came into the game) were mostly the MC-68020, and one or two examples of the MC-68030, which I never had.

I built a wire-wrapped computer at work using a MC-68B00 and a superset of the SSB monitor ROM. I did the assembly using a Tektronix MDL -- but at first I programmed the EPROMs with a suitcase-mounted manual prom burner (I forget the maker at the moment) until I wire-wrapped a burner for the 2716 to live in the system and expanded the monitor to include burn instructions. I could assemble the code in the MDL, and through a probe which plugged in where the CPU normally lived, I could load the program into a block of memory and then burn the EPROM on that with the MDL acting as the CPU, then switch back to the normal CPU and continue to use it without the help of the MDL.

Enjoy, DoN.

"Steve W." snipped-for-privacy@NOTyahoo.com on Wed, 23 Oct 2019 18:18:13 -0400 typed in rec.crafts.metalworking the following:

I recall reading about using paper or similar thin shims. But the wedge with fine thread might work too.

For real fun, work out how to do a "progressive twist" - where the rifling twist gets higher the further down the barrel the bullet goes.

A lost method to lay out mathematical curves on a long cylinder was discovered scribed on the unfinished wall of a Greek temple when it was excavated. Had they finished the temple the scribed markings would have been polished off. It's similar to the way I learned to lay out the patterns for sheet metal ducting transition pieces, and the full-sized ribs of sailing ships from the carved half model.

The desired curve would be drawn at full diameter but compressed mangeably small in length and divided by eqully spaced lines. For example it might be part of a parabola, the integral of a linearly increasing function.

to it the full size outline of the cylinder, a temple column, would be outlined and divided vertically by the same number of lines, spread out evenly. Then with dividers the position of each intersection of the curve and the verticals would be transferred from the small drawing to the full-sized one, and connected by scribing along a thin wooden strip bent to match them, giving the effect of drawing the curve accurately with impossibly huge instruments. The same method could lay out a progressively tightening spiral on the rifling guide, by transferring the heights of the profile of a curve to the guide with a fine chain.

A sine bar rifling machine can be built strong enough to drive the cutter directly from a straight or curved template, instead of guiding a pencil to draw the spiral groove on a wooden cylinder.

Paper shims under the single cutter were used in the Foxfire book. One groove was done at a time until full depth, then index for the next. I still have all the Foxfire books somewhere.

Pete Keillor

John B. snipped-for-privacy@fictitious.site on Thu, 24 Oct 2019 05:17:46 +0700 typed in rec.crafts.metalworking the following:

Once I figured out what he was doing, I saw how clever that method is. And adaptable, as in "one can easily change the twist, without having to make a new guide." The fun part is that now I have an idea for how to put spiral 'carvings' on wooden banister post. Now all I need is the lathe, and the space to set up. Oh, and a banister which needs posts. B-)

Here's the lathe you need:

A Rose Engine can create extremely complex geometric patterns like on the back of a $1 bill.

Similarly in England at the Portmouth blocks mills

.

The ideas underlying the Industrial Revolution were originally French, but England and then America provided more productive environments for their development. AFAICT automation was suppressed elsewhere to protect traditional jobs but that may not be the whole answer.

An engineer from India who resented the USA and Europe's domination of the modern world asked me why Europe had suddenly surged ahead of everyone else, particularly India and China, and I couldn't fully answer him.

There's an excellent video out there somewhere -- albeit possibly not on the net -- in which a rifled flintlock is tracked from wraapping & forge welding the barrel to rifling to making the lock and eventual proof fireing of the completed barrel. Details of the rifling process/tooling were pretty clear IIRC.

Sadly, I can remember neither the smith's name nor the "restoration village" where he worked for many years. Some grovelling through blacksmithing sites or googling for terms related to restoration or re-enactment villages might turn it up. Not in New England, more like somewhere in Virginia?

Here?

Yup. That's the one. Still can't remember the smith's name. I saw the film long enough ago that the guy doing the demo is probably long since retired.

I see from a quick gwgle that they substantially curtailed the gunsmith shop a decade ago. Too bad. You don't have to be a pathological firearms freak to appreciate the skill and workmanship and the importance of same in the 18th c.

I see that DVDs of The Williamsburg Gunsmith are available, albeit kinda pricey.

If you have an Apple device that can retrieve from the Apps store, there's an animation of Robbins & Lawrence Co. Rifling Machine No.1. Made in 1853, the machine is hand operated. You are able to zoom into each "subsystem" of the machine for a better look and description. The demo is making a pistol barrel, but the machine is also capable long barrels too.

Steve

I forgot. The app is "3D Rifling". Searching for "Robbins, et. al. won't find it.

Steve

One theory: the black death resulted in younger property owners, who could foresee a long life ahead, and weren't inclined to be staid and conservative. So, they innovated.

Younger property owners had no more expectation of a long life during the plague years than those they inherited the property from. "Eat, drink, and make Merry, tomorrow we die." A more likely theory: loss of work force allowed/required innovation. You needed more efficient technologies, you couldn't just add more manpower. And, there were fewer "old hands" to say that's not how we've done it."

On a side note, the Roman Empire had the technology to make steam engines. But there was no demand, in large part because those who could afford the expense of the machines, saw no need. They could always buy more manpower.