Manufacturers stubbornly prove that any manual labor can be mechanized. Electric drills replaced hand drills, chainsaws replaced saws. What about a hacksaw? Yes, here it is - a network and battery reciprocating saw, both for wood and for aerated concrete, capable of working on concrete, metal and even stone; how to choose it, learn from the article!
Reciprocating saws - this phrase in itself does not always cause understanding even among experts in electrical engineering and its sellers. Surprisingly, in the West this tool is as popular as an electric drill or a chainsaw, everyone knows about it and uses it in every home. It is not clear why such a saw did not please the Slavs, although, most likely, we, due to certain stereotypes and banal economy, simply cannot appreciate the tool.
Perhaps the whole point is that we don’t often have to deal with - the townspeople live in a concrete jungle, where dynamite is more useful than a hacksaw, and in the villages they prefer to work the old fashioned way. But it is to the hacksaw that the reciprocating saw is closest in terms of the principle of operation, but, in fact, it performs its functions, only instead of muscular traction, an electric motor works.
In the tool itself, everything is quite simple - a long body with an easy-to-grip handle in the shape of a familiar pistol, a trigger, several switches, a replaceable working canvas - that's the whole tool, if you don't go into details. Even a person who has never dealt with it will understand the principle of operation of this power tool in a matter of minutes.
In many ways, the “saber” resembles a jigsaw, however, rather the opposite - a jigsaw resembles a reciprocating saw, because it was the first one invented! As in the electric jigsaw, the reciprocating tool reciprocates and gradually cuts the material, in the same way, the pendulum stroke function is also found in the “saber” models, which we will discuss below.
The difference lies in the size of the hacksaw blade, as well as in some distinctive functions that you can’t do with an electric jigsaw. For example, in the garden it will be much more convenient to work when cutting trees with a “saber”, and it will be difficult to cut metal or aerated concrete with a jigsaw. By and large, the reciprocating unit is “omnivorous” - we changed the blade depending on the need, and we can safely cut wood, steel, stone, plastic, ceramics, glass, foam blocks! Still need to look for this one!
It’s easier to make a list of technical professions that would not need this tool than to list all the professions and crafts that will only be happy with such a unit. It's not even about its functions, which at first glance can be duplicated by other tools, the layout of the products itself decides a lot.
The long blade and the special narrow elongated design of the gearbox allow you to work in places where neither a jigsaw nor a grinder can simply squeeze in, the cut can be made flush with a wall or other surface.
In addition, this tool works quite calmly on weight, regardless of the shape of the part, whether it be round pipes, square bars. And for pruning trees, such a tool seemed to have been specially invented! Moreover, you can cut both a large branch and small wen. Maneuverability is the second name of a reciprocating saw! She will work as her master's hand leads - if necessary, she will round off an acute angle or cut a part out of curved material.
The tool also shows itself excellently during dismantling work - it cuts the old window frame very quickly, disassembles steel heating. The tool is able to cut even wooden surfaces with metal parts, for example, old nails or self-tapping screws, and this, you see, is beyond the power of any electric jigsaw. And a very important advantage of reciprocating saws is that they are much safer than chain saws, circular saws and grinders, during operation there are no sparks, clouds of dust, scale, there is no overheating of the workpiece.
Manufacturers produce reciprocating saws in different price categories, but in general, two types of devices can be distinguished: professional and amateur (or household). The latest models focus on a short period of continuous operation, 3-4 hours a day. This does not at all indicate a low build quality, they are simply designed differently and need periodic “rest”, while a professional tool will work the entire shift without stopping due to especially durable parts. Of course, household models are sometimes several times cheaper.
Reciprocating saw KRESS 1200 SPE its technical characteristics
Convenient and dual-mode speed adjustment using the "wheel" and the start key. The electronic control wheel allows you to set the maximum number of revolutions required for the job at hand. Smoothly pressing the starting key of the switch, regulate the number of revolutions of the already turned on tool. When the load increases, the electronics ensures that the required power is maintained.
The saw fits well and comfortably in the hands. although it weighs about 4 kg. Thanks to the soft rubberized non-slip coating on the surface of the gearbox and handle, additional comfort is created, vibration is smoothed out and hands hold the tool securely, which ensures safe work even in conditions of high humidity.
Saw blades in this tool can be replaced without using a special key: just turn the ring counterclockwise (there is a marking on the ring) until it stops, insert the blade and then release the clamping ring (photo 4). Be sure to check the strength of the fixation of the canvas before work. It can also be fixed "tooth up". The supporting saw sole (platform) does not require the use of additional tools to install it in a position convenient for a specific job. It is fixed in the selected position with a special lever (photo 5). If necessary, you can adjust the "exit" of the saw blade to improve access to hard-to-reach places. By applying this adjustment, you can optimally use the length of the saw blade and thus increase its service life. It is forbidden to change the position of the lever during operation.
The 4 m long rubberized mains cable provides sufficient freedom of maneuver in the workplace. A special plastic suitcase is provided for storing and carrying the reciprocating saw. Since the number of power tools in my workshop is gradually increasing, I treat the convenience of storing it with a certain pedantry.
RECIPROCATING SAW TESTS
For all tests on the KRESS 1200 SPE, I used one bimetal blade. It is universal and allows you to cut both metal and wood with equal success.
Sawing wood. In order not to drive the tool in vain, I tried to cut firewood for the barbecue in the garden. When the pendulum mechanism was turned on, the speed of work increased noticeably. The number of revolutions was set to the maximum. And the tool did an excellent job with such work (photo 7).
And if wood with nails? I did one of the most interesting experiments. I remember how after a “meeting” with a nail during woodworking, I usually had to re-sharpen or replace knives and saws of any tool, both manual and electric, or replace the blade at the jigsaw. And the test tool showed only a barely noticeable increase in body vibration during the passage of the blade in the place where the nail was. If I had not specifically expected this moment, then it might not have been noticed (photo 8).
And then I tried to saw a metal water pipe 01 ". When sawing, there were no sparks, which is fireproof. The sawdust from the workplace was then easily collected with a household vacuum cleaner. You can work with this saw without fear that the particles of hot metal that occur when working with a "grinder" will damage tiles, plastic, will be left marked on wooden walls and interior decoration.When cutting metal, the instruction recommends setting the speed control to positions 2 or 3, that is, choosing relatively low speed. And the new blade cut the metal "like clockwork". It took less than a minute to cut one. The edges of the processed metal turned out to be smooth and neat (photo 9).
Now let's evaluate the accuracy of processing with this saw. For precise joinery work, such a tool with a thin vibrating blade is not always suitable. Although with a certain skill and experience, the quality of work will be no worse than when using a conventional hand tool. But for construction work, where special accuracy is not required, it can be very useful (photo 10).
Another important point. Thanks to the possibility of smooth adjustment of speed, by pressing the start key of the reciprocating saw, you can “saw” into the wood without pre-drilling it. To do this, the tool must be supported and held at a slight angle to the surface. Gradually, rotating it vertically above the fulcrum, immerse the saw in the material being cut. The initial position of the tool y is shown in photo 11.
This technique can be very useful when performing construction work.
You can install any saws, the author, as an experiment, decided to install a blade from a hacksaw for metal.
Everything is assembled quite simply, there are few materials needed and they are quite common. You can make all the details with a minimum set of tools, you will need a grinder, a vice and a file, this is the main tool with which you can make this device.
Materials and tools used by the author for homemade:
List of materials:
- steel rod;
- bearing;
- washers;
- two thrust bushings (fix the bearing);
- aluminum plates and corners;
- screws;
- steel rods of rectangular shape;
- hacksaw blade.
List of tools:
- screwdrivers and hex keys for screws;
- vice;
- file;
- ;
- ;
- markers.
The manufacturing process of the electric cutter:
Step one. We make a shaft
First of all, the author makes a shaft, for this you need a steel rod. We clamp the rod in a vise and cut grooves on it, as seen in the photo. The meaning of these grooves is to place the bearing on the shaft at an angle. The author forms the grooves using a conventional metal file. First one is made on one side, and then the second on the other.
Step five. Mobile platform
On the other side of the structure, a movable platform is located, to which the movement from the bearing is transmitted. This platform is a plate on which two rods are fixed. Bolts with nuts can be used as rods, if desired, they can be welded.
The moving platform is located in the center of the structure, on the sides there are two metal bars slightly less thick than the platform.
Step six. holding head
To the end of the moving platform, the author attaches the holding head, which is needed to attach the hacksaw blade. How to make it is also left behind the scenes. It is made of a corner and aluminum plates. The part is fastened with screws, first you need to cut the thread under them.
My workshop is quite small, so I have nowhere to put the band saw, and I need to cut blanks from round timber and other things. You can't use a hand saw. I decided to make an electric saw, taking the product as a starting point myford boy:
Of the equipment used in the manufacture of hacksaws, there is a Chinese lathe D180x300v with an "electronic guitar" (in this case, the splitter function for marking holes on the flanges helps), a milling attachment for this machine, a Chinese drilling machine, brought to mind, an electric jigsaw for cutting duralumin blanks, well, and a variety of hand tools.
I ask you in advance to treat with understanding some of the manufacturing techniques, as well as the excessive consumption of materials and the overly sophisticated design of some parts that could be made easier and faster. I have had a lathe for less than a year, so I can say that I haven’t played enough yet, and some things have to be done based on the capabilities of the equipment. A milling attachment, installed instead of a small longitudinal feed, cannot replace a milling machine, just as the rigidity of this entire structure is far from industrial machines, so do not kick with your feet for the cleanliness of processing some surfaces. I see everything myself.
The Englishman's version seems rather cumbersome to me - in particular, the motor standing behind greatly lengthens the structure, which I, huddled in a workshop of 150x150 cm, do not like. Therefore, a Chinese overlock motor with a power of 150 W, collector and very small, was purchased as an electric drive. The motor was tested by running at idle - there is almost no heating, the noise is negligible and acceptable. But there is one problem with the collector motor - they are quite high-speed, so you won’t be able to get by with one stage of the belt drive. You need to make a two-stage gearbox.
A couple of days before the start of the construction of the gearbox, from which I, like from a stove, decided to dance, my rotor in the Interskol drill burned out. As it turned out, it was very useful, since one reduction stage is made from the rotor shaft and the spindle gear of this drill. Also, for the saw from it, a mains wire, an interference suppression capacitor, a gear key and bearings will be used, which turned out to be alive and well and which we managed to remove without damage, picking up the inner rings.
First I tried to knock the shaft out of the rotor. Copper hammer. Then steel. Well, then I went berserk and, holding the rotor in the chuck of the machine, grinded off everything that was on the shaft:
The shaft is raw, but its end, on which the teeth are cut, is well heat-treated. For several years of work, the drill did not appear on the shaft at all, as well as on the spindle gear - in fact, this is what prompted me to use them. Do not throw away - after all, what can still come in handy!
Two side walls were made of 30 mm thick duralumin, the gearbox input shaft bearings and the secondary shaft bearing mounting flange are mounted on the left, the second output shaft bearing and the bushing will be installed on the right, which will be the axis of the saw pendulum. Since I don’t really like plain bearings, the bushing will be the inner ring of the needle bearing, for which the gearbox shaft bearing from the VAZ 2108 was purchased. The bushing, which is the outer bearing ring, was also purchased. Only rolling friction, only hardcore!
While I managed to finish the left wall of the gearbox:
Since a gearbox with an oil bath is planned, I made an oil drain channel in the wall so that the oil that got behind the first bearing of the input shaft would flow down without seeping out. How reasonable this decision is, only time will tell. It didn't leave me, in the end. In order to maximize the distance between the bearings, the bearing on the pulley side was seated in the wall only half of its thickness, after which a flange was pressed onto it, fastened to the wall with six screws:
The input shaft was machined in accordance with the required dimensions:
The output shaft bearing is mounted in a flange, which is attached to the left wall from the inside. This is done because the bearings of the primary and secondary shafts in the projection overlap each other:
The secondary shaft is only ready on one side so far, the second will still be machined to the desired size. The keyway for the gear was made handicraft: first, on a drilling machine, I drilled a hole with a diameter of 3 mm, and then, holding the shaft in the tool holder, made a groove with a cutter:
Here is what is ready for today:
There is enough space between the motor and the gearbox to fit a compartment with a magnetic starter and an interference suppression capacitor and chokes.
The first, belt part, provides a reduction of 1:4.5, the second - 1:8.6, so the total gear ratio of the gearbox is 1:38.7, which at the declared engine speed of 8000 1/min will give 207 rpm at the output.
As guides for the saw, I bought two gas springs from the back door of the VAZ 1119 - these are the longest that I could find, the length of the rods is something about 27 cm. I have already dismantled one, the second is yet to be. Good polished rods with a diameter of 10.00 mm are obtained, for only 300 rubles each. Hacksaw, most likely, the old Soviet one will be used.
As a vice, my very first vice, bought to me when I was 12-13 years old, will be used. They are with guide pins, prone to misalignment, but at the same time with a maximum opening of more than 100 mm, sort of. We still need to look for them. It's nice to give a second life to things that are dead weight!
An electric hacksaw, also known as a reciprocating saw, is a versatile tool that can cut almost any material, including wood.
It is similar in design to . But a wood saw does not need a flat surface on which the jigsaw rests. In addition, the latter will not cope with strong and tough materials, such as steel pipes or fittings, and a high-power reciprocating saw cuts them easily. Plus, it can be used to cut building materials in hard-to-reach places.
The most important indicator that you need to pay attention to first of all when choosing is power. According to this parameter, electric saws are divided into three groups.
Power from 400 to 600 watts. This electric wood saw can cut boards of small thickness (up to 3 cm), metal products during repairs, tree trunks and branches of small diameter. With the help of such an electric saw, home craftsmen carry out carpentry and locksmith work. It is easy to use even for housewives, putting things in order in the garden.
700-1000 W. This variety can also be classified as household, but it has much more possibilities. The electric hacksaw easily cuts rebar up to 22 mm in diameter, not to mention wooden products. It is necessary to pay attention that the length of the working blade is sufficient for cutting wood. Many choose a reciprocating saw to give this particular type.
More than 1000 watts. The tool can be attributed to the professional category, where an increased load endurance of the device is required. With it, you can cut bricks, cellular concrete blocks, thick steel billets, not to mention wood. There is always a use for a powerful electric saw in the house.
Working capacity should be understood as the time of uninterrupted operation of a reciprocating saw. Low-powered models can saw wood up to 25 hours per month. At the same time, after an hour of continuous use, it is recommended to stop the electric cutter so that it cools down. Overheating of the electric motor leads to a decrease in the working life.
This indicator is determined by the reciprocating movements of the working canvas. The standard characteristic is 2500-3000 rpm. It is necessary to indicate that different cutting speeds are used for different materials, so when choosing, it is important to pay attention to whether the tool has a speed adjustment function. This is an important point, on which not only the speed of work depends, but also the service life of the electric saw.
Note! For quick sawing of non-hard wood species, you can set the highest speed.
And one moment. Many manufacturers offer electric saws with a pendulum movement of the blade. This feature increases cutting speed but reduces cut quality. In many models, this feature is enabled permanently. And if the requirements for the quality of the cut are high, then it is better to refuse such saws in favor of those in which the pendulum stroke is turned on with a separate button.
The standard value of the cutting depth for all types is the same and equal to 200 mm. But when choosing, you need to pay attention to whether the electric wood saw has a cut depth limiter function, which makes it possible to make cuts of small depth.
Note! The essence of the limiter is that when it is used, the files wear out evenly, their service life is extended.
The cutting depth adjustment device can be key and keyless. The second option is better in terms of the convenience of setting this parameter.
The technical characteristic "stroke size" determines to what maximum length the blade of the electric saw blade is extended. The larger this parameter, the faster the cut. Different models have different characteristics, but the average value is within 30 mm.
The main purpose of the soft start is to reduce the load on the power grid while turning on the electric wood saw. The higher the power of the tool, the more important the presence of this function. This also applies to battery models.
A quick change of files is important when working with different materials. There is a so-called keyless replacement, in which you can remove and install a new canvas by simply pressing a button.
Since a reciprocating saw is a manual tool, its weight plays an important role in the application process. The larger it is, the more difficult it is to use the tool, when work is carried out for a long time, the hands get tired faster.
The design of the electric saw is quite simple and similar to the design of many power tools. It consists of:
The pusher converts rotational motion into reciprocating motion. In some models there is a so-called pendulum stroke. Its distinctive feature is to lift the file while moving in the opposite direction. This movement is provided by a pendulum mounted on needle bearings. The main task of the manufacturer is to fine-tune the stroke of the pusher.
How difficult it will be to repair an electric wood saw depends on the characteristics of the breakdown. If the reciprocating saw stops while cutting wood due to the guard being triggered, this may indicate that the teeth of the blade are dull or that the feed is pressed hard.
It turns out a beveled cut - the prism of the guide holder is dirty, the blade is dull or it is incorrectly selected.
The reason for not turning on the electric cutter may be a damaged cord, discharged batteries (in the case of battery power), or overload, as a result of which the protection is triggered.
In case of incorrect or weak fastening of the blade, it is necessary to check whether the clamping screw has worn out. It may be that a blade with an unsuitable shank for an electric saw has been selected.
If you want to disassemble the saw, then you need to unscrew the screws on the handle and pry off one of the plastic parts with something sharp. Sometimes the screws are hidden by a casing, in which case you must first remove it by removing the attachments from the hacksaw. It is not always possible to replace gears, bushings, bearings on your own, if only because you need to find the right parts. In this case, the tool is simply sent for repair to a service center.
From the principle of operation of a reciprocating saw for wood, we can conclude that the main requirement for the design of the tool is to change the rotational motion into a reciprocating one. Many power tools have only rotary motion. So, in order to make a hacksaw out of them, you need to come up with a nozzle that would turn rotation into movement along the axis of the cutting organ.
To make a reciprocating saw from a drill with your own hands, you need to order some parts made on a milling and turning machine. The nozzle is a sized fixture. Here, the accuracy of fitting each part to each other is important; it cannot be assembled from improvised materials.
To make the nozzle, you need a shaft machined on a lathe. On it, it is necessary to make two oblique grooves with a file in the middle, arranged mirrored from different sides. A conventional roller bearing is put on the grooves. Relative to the shaft, it is located at an angle created by curved grooves. When the shaft rotates, the bearing will create oscillatory movements about the axis. It will be the part that moves the pusher from side to side.
To prevent the bearing from shifting, it is fixed on both sides with bushings that are pressed against the shaft with screws. Washers are installed between the bushings and the bearing.
The shaft needs supports. They can be made square with holes for the shaft. On the squares from two opposite ends, M6 threaded holes are made for attaching other parts:
The pusher is primarily a bar, longer than the two installed on the nozzle. Secondly, in its design, small bearings are attached on one side with bolts. Their task is to create a level of displacement of a large bearing mounted on the shaft on the pusher. When the pusher is assembled with a nozzle, a large bearing in thickness will be located between two small ones.
The pusher itself should not be attached to anything. But so that it does not jump out of the nozzle during the operation of the electric cutter, a cover is mounted on top of the installed bars. Here it is necessary to understand that the fastening of the cover and the two extreme bars to the squares is carried out with one bolt or screw for each place.
In principle, the nozzle for the drill is ready. It remains to make a holder for the blade of the electric saw. There are a lot of options here. One of them is a square-section part in which a cut is made on a milling machine with a thickness slightly larger than the thickness of the file. Threaded holes are made from the ends (usually two), where screws of the appropriate diameter are inserted. They will pinch the file.
To attach the holder to the nozzle, you can use various fasteners. The simplest is to make a rectangular groove in the holder on the opposite side of the cutout, and fit the protruding part of the nozzle shaft to a square section. In this case, the dimensions of the shank and the dimensions of the groove should coincide with a slight increase in the latter.
To fix the shaft in the groove, it is necessary to make a threaded hole from the ends of the holder, where the screw is inserted. He will fix the shaft in the groove and transmit the reciprocating motion to it. The opposite end of the shaft, which is round, will be inserted into the drill chuck.
It must be understood that a reciprocating saw from a drill is a difficult manufacturing option; it is not always possible to make parts on your own. The assembly is simple, there is nothing complicated about it. But the nozzle is quite reliable, it will withstand the loads that will act on it in the process of cutting materials.
If desired, you can convert the jigsaw into a power saw for gardening and carpentry. To do this, you need to fix the saw blade on a piece of metal tube about 15 cm long. On the reverse side of the tube, a plate is screwed, which will be attached to the jigsaw. To guide the movement of the saw, a special auxiliary structure is made of wood. You can prepare its drawings in advance so as not to be mistaken with the dimensions.
