Electronic reversing in a perforator
Drilled with this torch. drilled in hammerless mode.So I noticed. the housing got very hot. Heated up to 70 degrees. I couldn’t stand it.It is a normal phenomenon? Although the body is metal, the heat sink must be.The following georators of other brands have a plastic sheathing on the body as I understand.Why is it done like this?? so as not to feel the heat from the housing?I try not to use the percussion method as the concrete passes. Using peoration. I get a hole on the back side of the wall.To avoid this, I personally drill a small 4 mm hole with an impact drill. and then enlarge it.
The second thing is the oddity of putting the drill bit into the drill bit chuck.The strange thing is that it turns out when you insert the handpiece into the chuck. it is not necessary to pull back its “collar” All geared motors have this peculiarity? I’m asking because. the second. with a vertical motor layout (a regular Chinese not Interskol) of the peorator. I pull back the “collar” to secure the tool.
Third. brush reverser.What does it give and what is the reason for doing it?Why there is less brush wear? There are still two brushes.May be a simpler design?On two impact drills, the reverse is from the switch. I’ve never had a problem. and will not be I think.
The peorator inside the gearbox contains t.н. the compression-vacuum mechanism, there is constant compression of the air, the air heats up quite strongly during compression, so the heating of the reducer housing is normal.All-metal gear case allows for better heat dissipation from the HLCM, so the tool can work longer and harder than tool with plastic shell gear case. but the surface gets hotter, it is normal.
Knocking out the back side of the “lens” when passing through the concrete is normal.
our geared motors are equipped with automatic toolbox, it does not require retracting the toolbox shell when inserting the drill, it makes it easier to install the drill. newer and more advanced design. You still have to pull the shell back to remove the drill. All Interskol torches except P-20/550ER have such a box.
26 mm Rotary hammer drill reverse chalne wali
As for the brush reverser. the conventional electronic reverser doesn’t allow you to use the motor in reverse for as long. the service life is shortened. This is because the position of the brushes is optimized for forward rotation. When using the brush reverser when turning on the reverse direction of rotation by turning the brush holder, the position of the brushes also becomes optimal. That way, the brushes don’t wear out so quickly, and the motor works at full speed.
The electronic reverse usually reduces the service life of the brushes by a factor of 8 to 10 in the reverse direction. In the reversing gear, there is the same amount of wear on the reversing side as on the reversing side.
Choosing a foot drill. what to look for
Peorator (not to be confused with an impact drill) is a tool whose main purpose is to drill and chisel in concrete. Since it is seldom possible to drill through concrete with an impact drill, it is best to use a foot drill for this purpose. What’s the difference between the two, you might ask?? Let’s answer. the difference is the impact, that is, the percussion mechanism.
If in a drill, the impact is due to the alignment of the teeth of the sprocket (as a consequence, the tool quickly wears out if they often work in the mode of impact), the impact in the foot drill is electric, the force of which is many times greater than the impact of the drill.
Pe is indispensable if you live in a panel house, and for bricks it is preferable to use the same.
In general, the tool is necessary and in some cases simply indispensable (when you need to drill through the ceiling over the windows to hang curtains, for example).
It is a pleasure to work with it, it drills concrete very easily and you do not even need to push the tool, it will do everything by itself. Drilling is carried out by special drills, they are also called drill. The difference between a drill and an ordinary drill with a solder in the shank. drills have a special connector for attachment, they come with 2 kinds of connectors. sds and sds max.
SDS is the most “popular”, SDS drills are most often used in small peorators, just for home and small jobs. SDS max. for industrial models, power from 1500 watts, it is a big tool, such peorators weigh 7-15 kilograms. So, we will not talk about them anymore. We will choose. What to choose, what to pay attention to. all in this article.
As in the choice of drill, here also in the first place look at the power. the main criterion. It is needed for drilling large diameters in concrete and brick. In general, about how to drill concrete, we will have another article. Very often peoratorom drill holes “for sockets”, the work is done with the help of carbide bits of large diameter (the standard for the socket 68 or 79 mm).
It is for this kind of work requires high power, for the home the best choice would be a 700 watt torch. it is small in size, yet powerful and handy. It will perfectly cope with drilling holes in concrete from 20 mm in size, you can drill with both drill bits and drills. It is worth noting that the maximum size of the drill, which can easily drill concrete, these peoratorov 26 mm. Very often the model has the maximum diameter of the drill in the name, for example, Bosch 2-26 means that the maximum diameter will be 26 mm.
Next, and I would even call it one of the most important criteria in choosing a tractor, are the working modes. So, the paw can work in 3 modes: drilling with impact, drilling and chiseling.
- Impact drilling is the main operating mode of the drill, and I use it to drill through concrete, brick, and other stones. This mode is present in all models, as it is the basis of the basics.
- Drilling without impact is also the basic mode, that is, twin-mode geared drills have these two modes. When to use tapping holes? When drilling large diameters in brick and concrete with tungsten carbide drill bits. If you drill with a hammer, all the tips will fly off. Tile, porcelain tile, marble and granite tiles can also be drilled without impact (when no drill and suitable tile drills are at hand).
- Chiselling, an additional mode, is indispensable when it is necessary to break masonry, to cut a big hole in the wall or to chisel away tiles from the wall. When working in this mode, there is only a blow, there is no torsion. Especially for this mode, there are nozzles for the tool. a chisel (wide or narrow), spade, a rounded chisel (for routing under the cable). Needless to say, that often we need the third mode (chiselling), so when choosing pea, pay attention, that it must be 3-mode.
The reverse stroke (reverse) is useful if you have a drill stuck in the wall. It is so, when you drill with long drill bits (from 400mm and longer), they often get stuck in the wall at a small deviation. What to do if you have a drill stuck in the wall? The answer is simple. use reverse, so you can pull the drill out of the wall without breaking. It is a useful function, but not very often used.
A drill for infrequent home use. what is it? First of all, this is a domestic model, because buying a professional and using it several times a year is not profitable and the price for household. from 2500. there is a difference? Why overpay by 2 times if you will use the tool several times a year, when you decide to hang a shelf or re-hang curtains??
The whole difference between professional and household is the mode of operation, so we don’t need a pro tool for home, so let’s turn our attention to companies that produce household grade tools.
SKIL is the most popular company, subdivision of famous Bosch, household tools segment. Pey Skeel is a great solution for those who are looking for a tool in the house, they are powerful, reliable, durable. I personally know people who work with skils in a hard mode and they even put up with it for a few years. What can I say, quality assembly. That’s why we suggest you look into this great company. 2 year product warranty.
Black and Dekker is another company that designs and manufactures household grade tools. They have great drills, jigsaws, angle grinders, and the torches don’t fail. True, they are a little more expensive than the same SKIL models, but the difference is insignificant. 2 years warranty.
“Zubr”. not a bad choice for home, 3-mode models fully meet all the requirements of users. The tool is powerful, reliable, and has a 3-year warranty. At a cost of about 3000. “Zubr”. this is the same “Uragan”, a change of brand, so to speak. Peoratorov firm “hurricane”. the best models, 3 modes, not inferior to their professional counterparts, except for the mode of operation, of course.
In principle, these three worthy household brands, buying one of these firms peoratora you will not know the problems. This tool will help you do any work around the house, from drilling the wall for dowels to drilling “for sockets” and more.
Cordless or cordless
Battery technology is rapidly gaining momentum. Cordless torch is not a novelty anymore. However, when choosing between a corded and a cordless model, you have to understand that:
- Power of cordless model is noticeably lower (on average 1.4-1.8 J vs 2.5-3.5J for mains)
- Charge lasts not so long (depends on battery capacity and load, but usually it is about 20-30min)
- They are quite expensive
With non-professional use and work at home, as a rule, there is always the possibility of connecting to 220V, so, in our opinion, cordless torches makes sense to consider if:
- You already have a cordless tool and batteries of the right type (in this case you can buy a “carcass” very inexpensively. empty set of peorator without batteries and charger, for example Makita DHR202ZK)
- The convenience of working without wires for you outweighs all the disadvantages of this tool
However, progress is not standing still, and perhaps in a few years no one will even think of buying a cordless torch for home, all will be on battery.
Makita DHR202RF cordless drill
Adjusting the angle speed of an electric drill
The drill’s angular speed can be adjusted in two ways: electronically or mechanically. Both methods can be used simultaneously. The drill speed can be changed mechanically by changing the gear ratio. the gearbox with two ratios is usually used, to put it simply, a two-speed gearbox, less often a gearbox with a larger ratio. Decreasing the speed increases the torque, the output power remains almost unchanged.
A drill that has electronic speed adjustment performs this adjustment with the help of a rheostat, which is actuated by the force of the drill starter button. the deeper the button is pushed in, the higher the rotation speed. Often the drill has a small knob on the button, by turning it one can set the maximum speed limit. When you lower the speed electronically, the output power decreases. Nowadays, engineers, when developing drills, switched to thyristor power control, because rheostat control has its own disadvantage. High heat generation while the drill is in operation.
Sometimes electronic circuits are used to maintain torque, which make the product much more expensive, so they are rarely used.
Speed control is used to reduce speed when tightening and loosening screws, self-tapping screws, bolts, as well as when starting drilling (piercing), drilling fusible materials, drilling large diameter holes.
Just one piece
You need a double switch, a toggle switch, and a few strips of wire to accomplish the task. Voltage and current limits are marked on the switch body. The current on the switch should be equal to or greater than the current drawn by the tool. The current is not always written on the nameplate. Then we remember school physics lessons and calculate the current using the formula:
Don’t be seduced by modern miniature toggle switches. Their contacts are often permanently welded at the first switch-on, despite the current limit not being exceeded.
To the handyman from the handyman.
On these pages you learn about my work, products and ideas. I will try to supplement my videos with text and pictures, as well as with what is missing or cut from the videos. Regards Shenrok Alexander.
Sometimes it is necessary to change the direction of rotation of the power tool for craftsmen and self-made people. It would seem that it can be simple, you just swap the wires to the brushes and the armature will rotate in the other direction. True, the armature rotates in the opposite direction, but there is more arcing on the brushes, the motor power goes down, and the current draw goes up. And as a consequence, the motor is heating up. What’s the reason? What went wrong? Let’s try to figure it out.
In essence, the motors of most hand power tools are DC motors (DPT) with series excitation. And can be operated not only by AC current, but also by DC. And if you connect the motor of the power tool to direct current, its power will increase. This, if necessary, can be used in some, exceptional cases. But do not forget that the mode of operation of such a motor will change, and it will be necessary to monitor its temperature. And also some electronic devices, soft start, speed regulator, constant electronics, will not work if they are installed after the diode bridge.
The stator has two poles, positive and negative, reversed. And the armature is supplied with current through a brush assembly, and when it rotates, the poles of its magnetic field remain practically in one place, rather than rotating with the armature.
the positive pole of the armature is turned to the negative pole of the stator and the negative pole of the armature is turned to the positive pole of the stator. This armature will not rotate because the armature is not acting on the positive pole of the stator. In A, there are two forces moving from the center toward the poles. Let’s call this position “dead” for convenience
That is the positive pole of the armature is turned to the positive pole of the stator and the negative pole of the armature is turned to the negative pole of the stator. Practically such position is very difficult to find, but theoretically it exists. In this position, the forces will be directed from the poles toward the center and there will be no rotation either. Let’s call this position also “dead”.
The armature position is equidistant from the dead positions. That is the poles of the armature and stator are perpendicular. It is the position where the armature will feel the most force in one direction, and the position where you rotate it 180 degrees to the other side.
This is the best position for the armature in relation to the stator. And makes it possible to reverse by reversing the polarity of the brushes.
But, this is where the unexpected catch awaits us. So far we’ve looked at a static picture. And in reality, the armature rotates. And there are additional factors that come into play. For example, the armature has spun, the brushes have touched other blades and the armature needs to re-magnetize. It’s just the remagnetization that takes a certain amount of time. And that time depends on many factors. The composition of the metal, the mass and dimensions of the armature, the thickness of the plates and so on. And while the armature will be remagnetizing, it will have time to turn a certain angle, move away from the optimal position and come close to a dead point. The more the armature revolutions, the larger the deflection angle and therefore the worse the motor performance. And in order to return the armature to the optimum position, we have to start re-magnetization beforehand, i.e. to turn the brushes by exactly the same angle against the direction of rotation. With this in mind, industrial DC motors are made with a moving brush assembly. Which allows you to adjust the position of the brushes depending on the direction of rotation and engine speed, achieving the best efficiency.
But how do you solve this problem with power tools because the brushes are often mounted perpendicular to the stator windings. This angle is accounted for by the winding of the armature. And the windings are called “shear”. That is, the armature is already winded and the direction in which it will rotate is determined. Or the motor can be reversible, such as the motor of a modern washing machine, but this will worsen its characteristics.
The question arises as to how reversing is done in reversible power tools, drills, electric screwdrivers, peorators? It all depends on the manufacturer, the dimensions of the armature, the purpose of reverse. Some screwdrivers, which must both unscrew and screw, respectively rotate well in different directions, are made reversible. And since their armature mass is small and the speeds are relatively small, the deflection angle is correspondingly small. In drills, where reverse is not needed very often and not at full power, the manufacturers often limit revolutions in reverse by the limiter in the button itself. And here already on majority of torches (and on some powerful brand drills), we can see the reversing switch with displacing position of brushes.
Considering the above, we can conclude that if the power tool is not equipped with reverse, then changing the direction of rotation of the armature only by reversing the wires going to the brushes, we will worsen the electromechanical characteristics of the motor. And we can get a good result by changing the position of the brushes. By changing the position of the brushes by about 60 degrees against the rotation we want.
Operation of the torch in different modes
It is recommended to start drilling at low speed without pressing too hard on the surface. After starting the motor, let it idle for a while. This is necessary in order to avoid more complex consequences in the form of injuries, damage to building structures, complex breakdown of the tool in case of vibrations, extraneous noises or the appearance of smoke.
In the technology of work performance, much depends on the peculiarities of the material. For example, there are often questions about how to drill metal with a hammer. Experts recommend using only high-quality drills, which are specially designed for such operations from proven manufacturers. In addition, it is necessary to properly prepare the surface. The hole is performed in stages with a gradual expansion of the diameter to the desired size.
The common designation of the drilling mode in most manufacturers of construction tools has become a drill with a hammer. Particular attention should be paid in the course of work to ensure that the nozzle does not skew. It is also important not to exert additional pressure on the torch, this will not increase the motor power or speed up the work.
This function is not always used. For example, before drilling tiles with the rotary hammers, it is important to turn off the impact mode and prevent the drill from sliding on the surface, which often causes scratches.
To operate in the impact mode (the toggle switch is turned to the position marked with the hammer icon) special chisel tips are used. During operation, the hammer must be held with both hands. In the process of drilling speed can be adjusted depending on the characteristics of the work performed. It is necessary to constantly monitor the tool, since there are often situations in which the drill inside the structure bumps into reinforcement. If the hole is filled with crumbs, then to clean it, it is enough to remove the drill in idle mode (you can also use a construction vacuum cleaner).
HITACHI DH26PB. for occasional undercutting
The medium power dual-mode tool. Performs basic operations to create holes and recesses in concrete structures, brick walls.
Reverse Circulation Drilling Animation
Processes wood and wood product blanks in drill mode. Drills plastic, ferrous and non-ferrous metal. Improved durability due to changes in the percussion mechanism.