I've recently gotten into making PC folders with springs. All my earlier folders were friction, penny, or dorsal/"Spanish" locking types. In any event the blade rivet needs a precise 90 degree hole and I've actually been sort of challenged. Heavy, expensive drill presses have tables you can set accurately but a lot of drill presses aren't that great. In any event I have wondered how they got precision holes back in the late 1700's to early 1800's.
Precision drilling.
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They used both square and tapered square reamers to make a precision hole, even for small precision holes in clocks and pocket watches. The hole for the Frizzen screw was first drilled with a spade tip drill bit, then precision reamed with both parts being reamed for the hole at the same time with a square reamer, for example.
This information and a whole lot more can be found in the following book. It is one of THE main references used for 18th century tools by Colonial Williamsburg, the Winterthur Museum and other museums and is chock full of period tools including gunsmithing tools.
A Catalogue of Tools For Watch And Clock Makers
John Wyke of Liverpool
http://www.thebestthings.com/books/wyke.htm
Gus
This information and a whole lot more can be found in the following book. It is one of THE main references used for 18th century tools by Colonial Williamsburg, the Winterthur Museum and other museums and is chock full of period tools including gunsmithing tools.
A Catalogue of Tools For Watch And Clock Makers
John Wyke of Liverpool
http://www.thebestthings.com/books/wyke.htm
Gus
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Eh, sorry, how to use the tools is not in Wyke's catalogue - but tools to do gunsmithing as well as all sorts of metal work are. Sorry for any confusion.
Gus
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BTW, before his untimely passing, Gary Brumfield (who was the Master of the Colonial Williamsburg Gun Shop for years after Wallace Gusler) related how they could ream a barrel to .001" - .003" of any size they wanted with a square reamer and paper shims, though there were no precision instruments then to measure that precisely.
Gus
Gus
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Oh, another use for a square reamer was to ream the hole in a lock plate for the tumbler. That's how they got the hole so close in size to the post on the tumbler that went through the lock plate.
Even today, if you REALLY want a hole to be precise, you use a reamer after you drill the hole.
Gus
Even today, if you REALLY want a hole to be precise, you use a reamer after you drill the hole.
Gus
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Gus, he was not asking about a precise diameter, but how they got a 90° hole in whatever they were drilling. I would assume they had some type of drill press, or drill jig set up.
My suggestion would be to buy a tabletop drill press. Drill your stock when it is square, before shaping. Drill one piece at a time, never layers. The precision gain you will see is worth it.
Irondog54 said:
My drill press is a bench top and choosing it was a mistake. Really the floor models take up no more footprint than a bench top and are much more versitile.
I used a hand crank antique drill press for many years. Worked fine.
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Wick Ellerbe said:
OK, then. Here is what is claimed to be a very early drill press.
http://www.jimbodetools.com/Astoni...y-French-Blacksmith-s-Drill-Press-p40163.html
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I was thinking a post drill. I just didn't know how well made, that is, accurate they were. If you have a modern and inexpensive drill press where the table can be adjusted, the tolerances are often poor and setting it right at 90 degrees gets a 89-91 degree hole which might be okay for some jobs but is not really that accurate. A non-adjustable drilling jig would really work better.
THAT got me to thinking about the old methods. Some of the cheaper folding knives, such as Barlow, the sides were quickly forged with a trip/tilt hammer so you got the liner with an integral front bolster. No rear bolster meant you could pretty quickly fit a scale over each liner and trim to shape. I think the material was cut to length over a hardy (upside down chisel set into the anvil) and I am thinking the holes were punched and then reamed perfect in diameter and being square 90 degrees.
Although there were a lot of utility grade folding knives some were finely made, really works of art, the blades mirror polished, the scales made of fine skip line checkering or mother of pearl, etc. and the bolsters engraved- equal to anything made today. My current project is going to have a square tang, the angles have to be perfect so in a closed position the sharp edge is just off the spring, hitting the spring or resting on it could damage the edge. My efforts so far are "so-so" I'm making patterns from Plexiglas. Plexiglas is great for this type of work because it is flexible, in other words, in using Plexiglas the spring actually works, snapping the blade open and closed.
Given the primitive workshops back then- the quality of knives they made was incredible.
THAT got me to thinking about the old methods. Some of the cheaper folding knives, such as Barlow, the sides were quickly forged with a trip/tilt hammer so you got the liner with an integral front bolster. No rear bolster meant you could pretty quickly fit a scale over each liner and trim to shape. I think the material was cut to length over a hardy (upside down chisel set into the anvil) and I am thinking the holes were punched and then reamed perfect in diameter and being square 90 degrees.
Although there were a lot of utility grade folding knives some were finely made, really works of art, the blades mirror polished, the scales made of fine skip line checkering or mother of pearl, etc. and the bolsters engraved- equal to anything made today. My current project is going to have a square tang, the angles have to be perfect so in a closed position the sharp edge is just off the spring, hitting the spring or resting on it could damage the edge. My efforts so far are "so-so" I'm making patterns from Plexiglas. Plexiglas is great for this type of work because it is flexible, in other words, in using Plexiglas the spring actually works, snapping the blade open and closed.
Given the primitive workshops back then- the quality of knives they made was incredible.
BTW- for all you PC knife makers out there, Bernard Levine, "The Knife Expert" has the "Art of the Cutler" printed in France in 1776. It is a massive 3 volume set that covers setting up the shop, etc. etc. but it is in French. I think BL might set up a translated version on request but I've never asked since I'm at the hobby level but that French book probably has a wealth of information in it. There was a Novelle-France trade goods site a while back, no longer around. Kevin something (forget the guy's last name). I think a lot of the drawing and images on that site were from the French book I mentioned.
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Excellent Gus. I have seen one like it somewhere before. Thanks.
I have an antique hand cranked blacksmith's post drill in my shop. It will drill a very precise hole. Sometime in it's past the chuck has been updated from the square shank to a Jacobs chuck to accept round shank bits.
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Most any drill press will do what you need. If not dead perfect square, they usually can be shimmed so, or at least so close as to not be noticeably off. Bear in mind, for everything to come out dead perfect, your material being drilled will also need to be dead perfect. You might need a mill to do better than a drill press, but they don't come cheap.
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Since the holes for the Tumbler, Sear Screw and Frizzen Screw through the lock plate need to be as close to perfect 90 degrees as possible, I thought to check the Journal of Historic Armsmaking Technology, Volume I again to see how they suggested it was done. Page 32 says the following:
“In drilling with a brace and bit, it is helpful to have an assistant make visual verification that the bit is held ninety degrees to the plate. If the holes are not perpendicular to the [inside] surface of the lock, the screws threaded into them will lean and the sear and tumbler will bind. A thick drill jig, probably made of steel and hardened, used to position the bits at the correct angle and location on the plate of Italian musket locks is illustrated in Disequi D’Oqni Sorta De Cannoni Et Mortari. Any shop producing large numbers of locks very likely had similar templates for drilling.
Without the template to ensure accuracy, it is best to drill undersize holes and ream them to diameter. If one of the pilot holes shifts locations or cants slightly, it can be brought to center by filing.”
A visual verification could have been done with a Square to begin with and rechecked during drilling with a small block of Iron/Steel filed on at least two edges to 90 degrees.
I imagine a drilling template was also made for production of knives, as needed.
Gus
“In drilling with a brace and bit, it is helpful to have an assistant make visual verification that the bit is held ninety degrees to the plate. If the holes are not perpendicular to the [inside] surface of the lock, the screws threaded into them will lean and the sear and tumbler will bind. A thick drill jig, probably made of steel and hardened, used to position the bits at the correct angle and location on the plate of Italian musket locks is illustrated in Disequi D’Oqni Sorta De Cannoni Et Mortari. Any shop producing large numbers of locks very likely had similar templates for drilling.
Without the template to ensure accuracy, it is best to drill undersize holes and ream them to diameter. If one of the pilot holes shifts locations or cants slightly, it can be brought to center by filing.”
A visual verification could have been done with a Square to begin with and rechecked during drilling with a small block of Iron/Steel filed on at least two edges to 90 degrees.
I imagine a drilling template was also made for production of knives, as needed.
Gus
Thanks. A drill jig template for gun locks. That would create a uniform spacing of holes, etc. On the inexpensive folding knives I am thinking a similar devise may likely have been used, if this template was thick enough, you'll get the 90 degree angle; plus, on the folding knife liners all the holes are properly spaced. The earlier folding knives had integral liners/bolsters. Once sheet metal and metal stamping was economically developed (I forget exactly but say mid 1800's) then liners with applied (riveted on) bolsters because ever more common.
I agree that they probably had rather impressive drilling jigs to ensure a 90 degree hole, in a smaller shop it might have been a two man job with a helper spotting the angle of the drill with the work. I believe that something of this sort was discussed in the Journal of Historical Armsmaking that showed how locks were built in small shops.
As for today, a milling machine would be a worthwhile investment if you are doing a lot of folding knives. I have several Bridgeport mills at my disposal and they are all excellent and would be my pick of a manual mill. Surprisingly they are quite cheap in some parts of the country and would be ideal if you have the room and power for it. I have also been working with the new hi torque mini mill that Little Machine Shop sells and it is one of the better models of this type. It takes standard R8 tooling. If this was all that I could have I would not be at any particular disadvantage with it for smaller projects like you describe. As a plus, with the use of the R8 collets you can do some very accurate metal turning in it as well which can be useful for many things if you don't already have a metal lathe.
As for today, a milling machine would be a worthwhile investment if you are doing a lot of folding knives. I have several Bridgeport mills at my disposal and they are all excellent and would be my pick of a manual mill. Surprisingly they are quite cheap in some parts of the country and would be ideal if you have the room and power for it. I have also been working with the new hi torque mini mill that Little Machine Shop sells and it is one of the better models of this type. It takes standard R8 tooling. If this was all that I could have I would not be at any particular disadvantage with it for smaller projects like you describe. As a plus, with the use of the R8 collets you can do some very accurate metal turning in it as well which can be useful for many things if you don't already have a metal lathe.
I agree milling machines are the way to go but I'm a hobbyist rather than a professional maker. A pro has to eat so time is money and the fastest way to do the job enters the picture. If you are a hobbyist you can take forever and a day. I think the nail nicks on the very old pocket knives were stamped rather than ground like today. I say this because if the stamp is held at an angle one side of the nail nick will end up being deeper than the other and you see old knives like that. The other detail is the stamp was a curved crescent line. You can't easily duplicate that with a milling machine. What the milling machine does is cut a nail nick that is straight across on top and curved on the bottom and looks similar except for the straight line across the top.
I've seen photos (Simeon Moore Book) of old 1820 "ish" folding knives and the balance rivet (front rivet on the spring) can't be seen on a few knives. "how'd they do that" I wonder. My thinking is that the balance rivet was only as wide as the spring and liners and was covered and held in place by the scales. When you think about it, the blade rivet is supported by the shoulder bolster and the anchor (back rivet on the spring) is supported by the heel bolster so the only rivet that would be unsupported would be the balance rivet and if you tried to peen hammer the thing to hold it in place, there was probably a good chance of splitting or breaking a delicate scale made of bone or pearl...SO the covering of the rivet would actually make a lot of sense.
In any event, some guys enjoy making rifles more if they use only original methods and tools. I'm sort of applying the same thing to period knives- or at least trying to move in that direction.
I've seen photos (Simeon Moore Book) of old 1820 "ish" folding knives and the balance rivet (front rivet on the spring) can't be seen on a few knives. "how'd they do that" I wonder. My thinking is that the balance rivet was only as wide as the spring and liners and was covered and held in place by the scales. When you think about it, the blade rivet is supported by the shoulder bolster and the anchor (back rivet on the spring) is supported by the heel bolster so the only rivet that would be unsupported would be the balance rivet and if you tried to peen hammer the thing to hold it in place, there was probably a good chance of splitting or breaking a delicate scale made of bone or pearl...SO the covering of the rivet would actually make a lot of sense.
In any event, some guys enjoy making rifles more if they use only original methods and tools. I'm sort of applying the same thing to period knives- or at least trying to move in that direction.
