You've finally decided to make your first folding knife. This is right. In any case, this one delivers to me great pleasure, and the result inspires new creativity. Give it a try. You won't regret it anyway. Someone smart once said: “it’s better to do it and then regret it than to regret not doing it.”
Since you have already made up your mind, it means you have some design ideas. Let's assume that you have chosen a lock (Liner Lock), and this is one of the best knife locks. If not the best. It contains a minimum of parts, which means it has maximum reliability.
A little history. The modern linear lock was invented by Michael Walker in 1981. The most important thing Michael did was create independent system blade fixation, which has only one spring. The lock's leaf spring not only locks the blade in open position, but also ensures its reliable fixation when closed.
In addition, this lock allows you to open and close the folding knife with one hand. This invention in the full sense of the word changed the face of the modern folding knife. Honor and praise to him for this.
Make a sketch of the future design on paper or in some graphics editor. For example, it turned out like this:
First of all, choose your materials. It is preferable for a blade, since if moisture gets inside a folding knife, the moisture is not so easy to remove. Therefore, if there is something to rust, it will rust. If there is a thermal operator capable of working with high-carbon alloyed stainless steels, then you are very lucky in life (at the level of happiness).
If not, you will have to work on hardened material, and this is not easy. To drill holes in hardened metal, I use ceramic and glass drills with an arrowhead tip. You need to work hard, at low speeds, but carefully. You can chip the drill. And, of course, monitor the heating of the part. Be sure to refrigerate frequently, otherwise it will release.
Give the required form blade. I have used blades from Tramontina Professional Master series knives several times. They are a little more expensive than regular kitchen appliances from this company, but they are made from Sandvik 12C27 or 1.4110 from Krupa. This is good steel.
For folding knife dies, I recommend titanium. Despite its small thickness, it is quite strong and has sufficient rigidity and springing properties. In addition, titanium is lightweight and does not rust at all. There are some peculiarities in titanium processing.
Titanium should be worked at low speeds. For example, I couldn’t cut a 4 mm plate with a grinder, but I could easily cut it with a hacksaw for metal, although it took a long time. The thread in titanium must be cut slowly, with oil, going back every 0.5-1 revolution.
To cut out the contour of the locking spring in the bottom die, at the place where it is supposed to end, I drill 3-4 holes with a diameter of 2.5 mm, connect them, and place them there hacksaw blade and forward. Slowly, almost to the hole for the axle. In this place, I also recommend drilling a small technological hole for a clear end of the cut. All that remains is to saw through the line of the stopper itself. Here it is necessary to leave a reserve, which is then removed when setting up the lock.
The second, upper, die has exactly the same dimensions (as a rule) as the lower one. But it must have a recess for a hole for opening the knife. All mating holes should be drilled in batches. Start with the holes for the axle. Do not forget that the diameter of the holes for the fastening screws in the lower die must be threaded, and in the upper one the diameter of the screw.
So everything is cut and drilled. Select, or make your own, two fluoroplastic or bronze washers that will be used as a bearing on the axis of rotation (folding) of the knife. Insert the axle into the lower die, install the locking pin, washer, blade, and fold the future folding knife.
If something doesn't match, adjust it to the correct size. This must be done very carefully and carefully. Remember Zhvanetsky: “One careless movement: and you are a father.” Well, everything fits together!
On the locking spring of the lower die, mark a place for the ball and in this place drill a hole with a diameter 0.1-0.2 mm smaller than the diameter of the ball. I use balls with a diameter of 1.5-2 mm, from the bearing. Then, in a vice (placing a piece of hot metal under the ball, otherwise it will fit into the jaws of the vice), press the ball into the locking plate. The ball should protrude outward by approximately 0.5 mm. The thickness of the washer on the axis between the blade and the die.
Next, using a marker, draw in the place on the heel of the blade where the ball will move and fold/unfold the future folding knife several times. A clear mark from the ball will be visible on the blade. Stepping back 0.3-0.5 mm from the place where it (the trace) ends, drill a hole into which the ball will go in the folded position of the knife. Carefully bend the plate in the desired direction.
Assemble your future folding knife without the top die and adjust the lock (your stopper is cut out with a margin). Do this very carefully (remember Zhvanetsky). As soon as the lock engages, stop. Assemble the folding knife completely, with the top die, and try folding/unfolding it several times, apply force (as if cutting something). Do this several times. And put it off until tomorrow.
Final adjustment of the parts of a homemade folding knife.
Sleep with the idea that you have made your first folding knife. The next day there will definitely be something to finish. Bring the castle to condition. The locking plate should not reach the upper end of the heel of the blade, otherwise it will fall all the way to the top plate and jam the lock.
If the spring is too tight (depending on the thickness and brand of used
Jackknife - great tool in a man's pocket and more. You should definitely take it with you when going on a hike or just in nature. Using a knife, you can not only cut sausage or open beer, but also protect yourself from enemies. Moreover, more often the enemy is not a person, but an animal, for example, a dog or even a fox. In this instruction we will look at how to make a good simple folding knife with your own hands.
To make the knife, the author used a fairly professional set of tools; he needed a jigsaw and other tools. But don't despair if you have skillful hands, such a knife can be easily made with ordinary hand tools. The fixing device for the knife is also simple; all parts are made by hand. So let's get started.
Materials and tools used
List of materials:
- high carbon steel (which can be hardened);
- pins (can be steel or brass);
- material for the linings (wood, plastic, and so on as desired);
- epoxy adhesive;
- spring rod (for making a spring).
List of tools:
- ;
- drilling machine or drill;
- clamps;
- Bulgarian;
- vice;
- paper, pencil, scissors for making a template;
- sandpaper;
- furnace, oil for hardening.
Knife making process:
Step one. Sample
First of all, the author makes a template, including everything internal parts. For those who have already made a knife at least once, it will not be difficult to make such a template. You need to think over a locking mechanism; it is made in the form of a lever with a hook.
Step two. Cutting out blanks
The author cuts all the parts of the knife from sheet steel. The locking mechanism consists of two parts, one part holds the spring, and the second is a lever with a hook that holds the blade.
To make a handle, you will need to carve two identical parts. The author cuts out all the details, including the blade, using a grinder. IN hard to reach places where it is impossible to reach with a grinder, we make a lot of cross cuts, and then gradually cut them out.
To make a blade, you will need steel with a high carbon content; in America it is customary to use 1050 steel; in Russia, the most common grade of steel for making knives can be considered steel 65X13. Good steel, which can be hardened, is widely used in tool making. You can also use steel from an old cutting wheel.
When you cut out the blanks for making the handle, assemble them on pins or simply on bolts. Now sand the product along the contour, in the end you will get two identical parts.
Step three. Grinding
We proceed to finer processing of workpieces, namely grinding. This is where a belt sander comes in handy. We bring the details to perfection, and at the end we go through them manually with a file where we couldn’t get them with a machine.
Using grinding machine, you also need to bring out the bevels on the blade. The author attaches the blade to a special device and gets to work. Main criterion here – the symmetry of the bevels.
Finally, the author processes the parts manually using sandpaper. The next step for us will be hardening; before this, do not forget to drill all the necessary holes in the workpieces, since this will be problematic later.
Step four. Tempering the blade
In order for your knife to hold its edge for a long time, the blade must be hardened. Since we have the blade small sizes, it can easily be heated to desired temperature using a burner, as the author did. We heat the metal until the steel is no longer attracted by the magnet. If we take a more professional approach to this matter, then for each steel there is a clear heating temperature.
When you heat up the steel, lower the workpiece into the oil. Used oil from a car, as well as vegetable oil, is quite suitable. After cooling the workpiece, run a torch over the metal to burn the oil. Now the steel can be checked; if it cannot be taken with a file, it means that the hardening was successful.
The next step in hardening is necessarily tempering the metal, otherwise the steel will be very brittle. A household oven is suitable for holidays. Place the blade in it and heat it for about an hour at a temperature of 200-250 degrees Celsius. Then let the oven cool closed with the knife inside. Vacation is done! Now the steel will spring back and the blade will not break when high load.
Step five. Let's move on to assembling the knife
After hardening, polish the blade until it shines, as after heat treatment it will change color. Now the knife can be assembled. Lubricate all internal parts with motor oil to prevent the knife from rusting on the inside. Now we assemble everything on pins. We glue the overlays using epoxy glue.
Clamp the handle tightly with several clamps and let the glue dry completely. Epoxy usually dries in about a day.
When the glue is completely dry, we perform final sanding. First, the product is processed using a grinder, and then manually using sandpaper. Finally, we bring the handle to perfect smoothness using fine sandpaper.
Manufacturing should begin directly with the blade. First of all, mark the place for the axial hole. We drill it and, using it as a guide, we make further markings of the blade. If you do the opposite and mark and cut the blade along the contour, and only then drill a hole, then during the drilling process, especially in hardened workpieces, the drill can move to the side and all dimensions will “float away”.
Having transferred the contours of the blade to the workpiece, we begin to make the blade. We grind it using a grinder and sandpaper along the contour. For the convenience of holding the blade during the process of removing the slopes, we do not yet cut off the blade itself from the workpiece and do not form the heel of the blade.
To remove slopes, you can use various tools: grinders, sandpapers, flat grinders, grinders. I do rough grinding of the slopes on sandpaper and fine grinding on a surface grinder.
Next, we begin making the side dies.
Next, drill a hole in the dies for the blade stopper pin, install the axis and stopper pin, install the blade and the second die. We move the blade to the open position and mark on the die the position of the heel of the blade, or rather the place where the lock liner should rest. Next, mark the liner and start cutting it out.
Having prepared the pritins in this way, we proceed to install them on the dies. There are different methods: soldering, riveting, spot welding etc. The most accessible are soldering and riveting.
For soldering you will need a soldering iron, soldering acid, solder and a heat source. As a soldering iron, it is best to use a massive piece of copper, which is heated in the flame of a burner. Soldering acid- This is hydrochloric acid etched with zinc. POS-60, POS-90 are suitable as solder. Before soldering, it is necessary to clean and tin the soldering areas. Cleared sandpaper, needle file. After cleaning, coat the soldering areas with acid, take a piece of solder on a well-heated soldering iron and tin the surface. During the tinning process, care must be taken to ensure that there are no gaps left and that the entire surface is covered. even layer solder. High-quality tinning and soldering are possible only with good heating of the parts.
After servicing, rinse the parts thoroughly in water and soda, removing any remaining acid. Next, we clamp the tinned parts in a vice and begin to heat them with a burner with different sides. To reduce heat loss, thermal insulating material must be laid under the jaws of the vice; fragments of ceramic tiles work well. As it warms up, we press the vice until droplets of solder appear between the parts, after which the heating can be stopped.
Soldering the right-hand prytina has features: first we solder the knife axis into the die, and then solder the pritina, while instead of one of ceramic tiles We use a piece of tube larger than the diameter axis.
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| So, all the components of the knife are ready, all that remains is to assemble the knife and once again make sure that the lock is working correctly. Adjust if necessary. For smoother operation of the mechanism, it should be lubricated with machine oil. After some time of operation, the parts of the mechanism will rub in, the blade will rotate easily and smoothly, and the liner plate will rise slightly upward. |
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In the most simple models the blade is not locked in the open position: it will fold if you press it hard enough in the appropriate direction. This is how a classic pocket penknife works. In English literature, a knife equipped with a similar mechanism is called slip joint folder, or a folding knife with sliding connection(rather, articulation).
I could not find the corresponding Polish term. Well, okay, it doesn’t matter what it’s called scientifically; what matters is how it works. A spring, attached with one end to the upper edge of the handle, with its other end presses on the disc-shaped surface of the back of the blade. And this surface is designed in such a way that both opening and folding the knife causes the spring to bend or unbend; at the same time, it provides a certain resistance, which allows you to hold the knife either open or in closed position(ill. ). But if in the folded state the spring holds the blade quite reliably, then in the open position such a knife cannot be called one hundred percent safe. In practice, you have little to fear if you only use the knife for light, well-controlled cutting—for example, opening correspondence or sharpening pencils. Perhaps this is why such models are becoming a thing of the past; few of them are produced now. Even typical multifunctional pocket knives are now increasingly equipped with mechanisms that allow them to hold at least one, the largest (main) blade in the open position.
Well, to complete the review of the anatomy of folding knives, we should consider one more the most important detail, for some reason in the above article only mentioned in passing: fuse/lock. A lock is a mechanism that secures the knife blade in the “open” position and prevents it from closing spontaneously. For modern folding knives, many various designs castles, it is difficult to say which one is better - each has its own characteristics.
Liner lock
The most common type of lock, relatively simple to manufacture and yet reliable enough for most everyday tasks. The lock mechanism is based on a flat spring, which is part of the liner and rests against the shank of the blade when the knife is opened. You should pay attention to how far the spring extends onto the shank - this largely determines the reliability of the lock. This distance must be greater than the thickness of the spring itself, otherwise the knife may fold under light pressure. 
Framelock (monolock, integral lock)
A type of liner lock. The only difference is that the role of the locking plate is played by part of the knife handle, which in such cases is made of metal. This adds strength to the entire lock, because... In this case, it becomes more difficult to deform the spring. In addition, the hand holding the knife additionally presses the locking plate. 
Back lock
In castles like back lock the shank of the blade is fixed on the side of the butt by a spring-loaded rocker arm. These locks are more difficult to make due to the fact that the part of the rocker that engages and the slot on the shank must fit together quite precisely. Otherwise, the blade is either poorly fixed (the rocker arm does not fully fit into the shank) or wobbles (the rocker arm fits in freely). And even if they are identical, at a certain load vector there will be a slight backlash, which is due to the design itself. 
In 2008, Cold Steel refined the back lock and introduced its new creation - Tri-Ad Lock. The original design received minor modifications: a locking pin was added, which takes on almost the entire mechanical load, the geometry of the rocker arm engagement itself and the groove in the shank was redesigned, and the hole of the rocker arm axis was made oval. As a result, the strength has radically increased, and when the contacting parts wear out, the rocker will simply change its position without increasing the play of the structure. 
Compression lock
It is a hybrid of liner lock and (to some extent) back lock. The peculiarity is that the flat spring rests on the shank not from behind, as in a liner lock, but from above. Another feature is that the spring extends onto the shank on one side and rests against the locking pin on the other side. An undeniable advantage of the mechanism is that when closing the knife, not a single finger will be in the path of the blade. 
Levitator lock
Knives with locks of this type are produced by Benchmade. Due to its characteristics, the lock can only be used in knives with a metal handle. A special pattern is carved on the handle, forming a spring plate, when pressed, the rod entering the blade's shank moves and releases the blade. 
Coupling lock
Under the name Viroblock is used in most modern knives trademark Opinel. The blade is fixed using a rotating metal coupling with a longitudinal cut. In the extreme position, the clutch blocks the opening of the blade, and when the knife is in the open position, turning the clutch in any direction blocks its closure. Considering the low cost of such knives, the lock on them is simply excellent. 
Pin locks
The AXIS lock type is a patented feature of Benchmade. The blade is fixed with a spindle-shaped pin, which fits into the corresponding grooves on the shank of the knife. In this case, fixation is carried out in both the open and closed positions of the knife, which avoids accidental closing of the blade. According to the results of testing the strength of locks on budget knives by enthusiasts of the website knifelife.ru, the most durable was AXIS in the Benchmade Griptilian 551 model. The main enemy of such a lock is dirt, which can damage the knife. 
Arc lock, patented by SOG, is very similar in principle to AXIS, but has slight differences - the pin is additionally secured to a small rocker arm inside the handle. 
Rolling lock- another lock from Benchmade. Here the pin is completely inside the handle and is activated by an L-shaped lever with a pin extended outward. 
Ultra Lock- another type of pin lock, this time from Cold Steel. In this embodiment, the pin moves along a U-shaped groove in the blade's shank. The locking rod locks the blade at the extreme points, which ensures reliable fixation in the open and closed positions. 
Push button locks
Lock type button lock(or plunge lock) most often found on automatic knives. When pressed, a spring-loaded button-pin of variable diameter moves its thinner part into the plane of the blade and releases it. Holds the blade both open and closed. The quality of locks of this type depends entirely on the manufacturer. In general, they can be very durable, but they are afraid of dirt. 
Axial lock- a rather unusual lock, which puts most inexperienced knife lovers into a state of slight thoughtfulness. Such a knife opens and closes by pressing on the knife axis and turning it thumb. On the axis there are protrusions that engage with grooves on the blade and in the handle. 
Stud Lock
A movable pin lock design found on Kershaw knives. When opened, a spring-loaded pin on the knife blade engages a notch in the front of the handle. To unlock the blade, you need to move the peg towards the tip. With proper skill, closing the knife is seamless and quick, and the lock guarantees proper strength. 
Deadbolt locks
Lock ram safe lock mounted on a rather unusual and recognizable Cold Steel Pocket Bushman knife. For all its technological simplicity, the lock is very powerful. In it, the shank of the blade is locked with a rod (crossbar), which moves parallel to the butt. The rod on the opposite side of the blade is pressed by a rigid spiral spring, and in order to open the knife, you need to pull the lanyard. Opening (and especially closing) with one hand is extremely difficult, but in order to break such a lock, you will have to work hard. 
Design bolt lock differs from the previous lock by the presence of a pin attached to the crossbar and displayed on lateral surface handles The principle of operation of the lock is very similar to pin designs. 
Gear lock
In design ratchet lock(or cogwheel lock) the rounded shank of the blade is made in the form of a comb with straight or slightly curved teeth, and the locking is done by a plate-plate with a slot for one tooth. When the knife is opened, the plate rises, and all the teeth of this half-gear pass through it, and in order to close the knife, it is necessary to manually lift the locking plate (most often by the ring). The lock is traditional for Spanish Navaja knives, but is also found on South African okapi (and their modern incarnation Cold Steel Kudu). 
Balisong
It is difficult to call the design of a balisong knife (popularly called a “butterfly”) a lock, but, nevertheless, we will describe this method of fixing the blade. When folded, the blade is covered with halves of the handle on both sides. When opened, each half rotates 180 degrees; in some designs they are then secured with a latch, while in others they are simply held together with one hand. 
Slip-joint
Perhaps one of the simplest types of lock, which has found its use in many budget models tourist knives. In extreme positions, the blade is held from above by the rounded shank by a flat spring. The lock does not provide rigid fixation of the blade, but nevertheless prevents the blade from accidentally folding and damaging your fingers. 
Friction fixation
So-called friction folder- the oldest design of a folding knife, the blade of which is held open due to the friction of the shank on the handle in the area of the axis. Most of these knives have a lever on the tang that protrudes from the handle when the knife is closed. By pressing it, you can remove the blade from the handle, and then open the knife by the blade. IN open knife During operation, the same lever is pressed by hand and additionally prevents folding. Well-known straight razors, European medieval peasant knives and japanese knives Higonokami. 
