Your thread and lathe build is interesting, though I do question the practicality of the lathe. My lab has six Clausing Colchester lathes in 14 and 15 swing configurations and I strongly believe any of those would be a far more ridgid and better machine. These can also be purchased used for probably less than you have invested time and money wise.
I am also curious how much deflection you are getting and whether your outside profiles are concentric with the bore. Perhaps a bore size mandrel would be useful which could be turned on center. With a follower rest this should give you more consistent results and reduce chatter. If I was doing that job I would either switch to a CNC lathe, or better yet do as Mike suggested and simply buy the barrels. Those English doubles were the work of multiple specialists anyway, best to concentrate on a few key areas and let other experts help along the way. Just my thoughts.
Question away at the practicality! We worked that little lathe pretty hard today. I’ll share how it did at the end of this post. To buy a machine? I looked at used machines. I looked a new machines. Just the transportation costs to my shop put both out of the question. We have the will, we have the technology, we have the time so why not just build one?
Deflection? Just as any other machine it depends on how it’s treated or mistreated and the type of tool used. With a carbide insert we saw up to 0.004” midway between the chuck and tail stock but that was with an extremely aggressive depth of cut. A cut depth actually beyond the capability of the tool. With HSS and an aggressive cut the tool was wrecked before deflection became noticeable. There is no answer concerning concentric profiles. We won’t know that until we get one fully turned. Just as mentioned above, i’ll share the results of today’s turning session at the end of this post.
About buying barrels -Yes it would be simpler to buy them but barrels to replicate a circa 1760 William Bailes double barrel can’t be found or bought for any price. I’m sure you already know the story about having them made so i'll not repeat it here.
You’re right. Some gun makers of centuries past relied on multiple suppliers to build their wares just as today’s manufacturing. They may have had a stock maker, a lock maker, a barrel maker and so on. That would make their trade no different, imo, from building a contemporary gun from a kit. I don’t want a kit. I don’t want to rely on multiple suppliers to build this repro. It’s all up to me to bring this project to fruition. Why? Because I want to and I can. How arrogant is that?
Well, you obviously enjoy doing everything the hard way! I believe all the doubles I made had parabolic chambers. Had nothing to do with safety on my end, it was all about performance. I owned and shot and original SXS flint gun for a long time that was chambered. A real eye opener for me early on. Makes a huge difference on patterns and how hard the gun hit. It was an 18 bore and would smoke skeet with a 5/8oz shot and 55gr powder load.
I doubt Nock was the first to use a chambered breech, he was just good at marketing and self promotion, no different than the gun makers today.
Mike, really, the hard way? To me the hard way would be standing for hours and hours and hours dragging and pushing a file around just to shape a barrel. Who has the energy for that?
It amazes me how even a small change in chamber geometry can have a dramatic effect on ballistic performance. Isn’t it something though to see the look on someone’s face when you out shoot them with a flintlock double? Especially the guy with the $3,000 Benelli.
Mike,
Yes, there were all sorts of breech plugs, chamber plugs and such before Nock, , but Nock's was the one that got attention. It was more of a refining of a pattern.
I too have a double from 1815, and it shoots very well and fast. Platinum touchholes.
Its seen a lot of use, as the hammers have been re-faced at least twice.
It has chambers like you describe, or what Nock is famous for.
Hank,
Looking forward to updates, it's a big project!
I have to agree with you and Mike, Nock probably wasn’t the first to use a chambered breech, rather he took some one else’s idea, improved it and won his patent. Joe Manton did the same thing. Took Nock’s idea one step further to win his patent. Will we ever know who was the first? Probably not.
It is a big project. But, I knew what all it involved before deciding to go ahead with it. No doubt some folks here think i’m nuts but the best part of it is -I am nuts! But i've not had this much fun since the time Becky…. Oh, better not say that.
Making a lathe is a bit over the top but it is one more proof of some of the talents and abilities on this forum.Making your own tools,even simple ones like odd size collets is an accomplishment and a lathe to use them is indeed marvelous.Like many others here,I have had a big measure of personal satisfaction from making whatever is wanted or needed for a specific job.At one time I thought of making a small lathe dedicated to only screws and pins but I bought in 1964 a new Atlas 618 and still use it for whatever small jobs needed.I have a 2nd 618 given to me by the son of the man that bought it new in 1965 and it is a Craftsman because it was bought new at Sears&Roebuck.
Having a small shop is a blessing and even though I do little or nothing it is nice to know it's THERE if I feel like doing something,
Bob Roller
Bob, I see the making of things as a continuation of the pioneer spirit. This spirit, imo, is lacking in today's society. Even the desire to be creative seems to be falling from favor. Maybe i’m talking out the side of my head but i firmly believe if more folks were constructive there would be fewer destructive people on this planet.
It is nice to have things to work with even if they are hand made. Some of the weirdest, most useful tools in my shop are hand made. That’s what it’s all about. If you can’t buy it, make it.
Let’s talk about the lathe! We have one blank rough turned and ready for profiling:
Muzzle end is far right on the tail stock center. Wedding bands will go on the far left end, 20” up from the muzzle.
Machine drive ran flawlessly. The Teco VFD and Iron Horse three phase motor make a perfect combo producing smooth power at any RPM. Coolant system worked as it should. Carriage feed, after replacing the original ball screw, is smooth and responsive. But, some dunderhead (me) forgot to fully tighten the anchor screws of the cross feed ball screw after doing the carriage feed repair work. More about that later. As previously posted, experimenting on black iron pipe gave a good idea of how the machine behaves at various speeds, feed rate and with different tool types. Armed with that information, 2” of the muzzle end of a 19 bore Bailes barrel blank was turned to rough diameter using the experimental “lead rest”. The lead rest idea was abandoned in favor of a follow rest. This created a slight problem.
Since 2” at the muzzle was already turned to rough diameter, there was a very large step that the follow rest could not accommodate. Normally a pass or two is taken at the tail stock to true up the work piece in order to give the follow rest a true surface to ride on. The work piece is then turned full length with the follow rest providing additional support along the length of work piece.
There’s a lot going on in this photo:
Notice the large step in the work piece left of the coolant nozzle and tool post. It’s 0.110” deep, too deep to turn in a single pass. That exceeds cutting tool (and machine) capability. So, the tool was advanced to make a cut then the carriage was advanced until the steady rest made contact with the step. Carriage retracted, tool advanced, carriage advanced and everything repeated until the step was reduced to rough diameter. This continued full length of the work piece. Now, had the muzzle end not already been turned to rough diameter then the work piece could have been turned in single full length passes.
Also in this photo is where the loose cross feed anchor bolts was discovered but only after destroying a second HSS cutting tool. Well, not destroyed just dulled beyond use. After tightening the bolts a carbide insert tool was locked into the tool post and turning to rough diameter completed.
So how did it finish up? Take a look:
Not too shabby. It could be better imo but with an SCMT carbide cutter in this machine that’s as good as it gets. We’ll use a better grade tool to bring it on down to finish diameter and turn in the profiles.
Now for the other quality aspects, the barrel was checked after turning for parallelism and eccentricity. Starting from the muzzle, the barrel was marked lengthwise at 3 1/4”, 8 1/4”, 13 3/4”, 18 ¼” and 21 1/8” (at the chuck). With a dial indicator placed on the cross feed and zeroed at the muzzle, the carriage was advanced to the first mark and reading recorded for parallelism TIR at the mark. The barrel was then rotated at the mark and reading recorded for eccentricity TIR. This was repeated at each mark. Parallelism checked, starting at the muzzle, (in thousandths): 0, +5, +6 ½, +10, +14, +14 respectively. The barrel tapers 0.014” over 21” sloping down toward the muzzle. This is more than likely do to the way it was turned: cutting it down in steps as opposed to continuous full length turning. TIR eccentricity results really surprised me. Again starting at the muzzle (in thousandths): +/- 0.001, +/- 0, +/- 0.005, +/- 0.001, +/- 0.005, +/-0.001 respectively. Looks like the home brew follow rest works pretty darn good.
This lil machine worked hard today. Even got rough with it a time or two. That’s how the tooling got wrecked. But, the machine held up and did exactly what it was designed to do -produce a perfectly acceptable product. I’m happy with it.
What’s left? Figuring out what to do with this:
I’ll get a video of the machine in operation posted once I find the tripod for the camera. Maybe it’s in the box with Becky’s picture?
Hank