How to Choose a Punch for a Home Master
The material from which most of the modern housing is built is concrete. It can also be brick, cinder block and other fairly solid materials. Driving a nail into a concrete wall or screwing in a screw is no easy task. In private housing construction, sufficiently soft wood and cellular concrete are also used, then the inhabitants of apartment buildings still face the difficult task of overcoming the hardness of walls, ceilings or floors in order to equip a room.
For this purpose, a hammer drill was invented. A tool designed to work with solid building structures. On the farm, he certainly will not be superfluous, but for the right choice you need to take into account all the nuances.
What is the tool for?
A perforator is an electric building tool for drilling holes in solid materials that allow impact loads. In concrete, stone, brick, as well as for chiselling chambers, channels in softer materials: plaster, unreinforced concrete, gypsum and cement blocks.
The perforator can also be used to remove ceramic tiles and porcelain stoneware, the remains of the hardened mortar and tile glue.
In the slotting mode, a powerful puncher can be used as a jackhammer, crack concrete floors, cut corners and other stone and concrete structures.
The working part of the punch is all kinds of drills, drills, chisels, crowns, and other tools designed for rotational-translational movement during use. The decisive form of movement for the punch is still translational. Therefore, the drill does not have sharpening, and their head is equipped with special carbide blades that break the material during the impact, and at the same time remove it from the hole during rotation.
Some modern punchers allow drilling mode, but in this quality, punchers lose to conventional drills of similar power.
With the help of special nozzles, perforators can be equipped with mixers for building mixtures during drilling mode. With the forward movement of the drummer, it is possible to hammer nails, dowels, crutches, as well as attach compact vibration plates for ramming. True, only angular rotary hammers of high power can be used this way.
Differences from Impact Drill
Drilling with a blow can be carried out not only by a puncher. The hammer drill can do this too. But there is a fundamental difference between the two tools, which makes the puncher primarily a percussion instrument, and the drill a drill.
The drill is hit in the drill with two ratchets, which are opposite each other.
In the normal state, two ratchet wheels are divorced by a special mechanism.
When the drilling mode is activated, the mechanism retracts and the ratchets are pressed against each other.
When rotating, there is a slip on the ridges of the ratchets, due to which the drill rotates and at the same time periodically moves forward.
The impact force in the drill is extremely small, and is not intended for heavy loads. Piling on a drill to increase penetration is useless, this will lead to accelerated wear of the mechanism, and the load on the motor will only increase. The use of an impact drill is justified for some types of bricks, cellular concrete and other not too hard materials.
Unlike a drill, a completely different mechanism is used in the puncher to give the drill translational motion. The most common are perforators with a pneumatic impact system. They use a cylinder with a piston that compresses the air. The force of compressed air pushes the hammer, which acts on the shank of the drill, chisel or other device.
The first piston is driven in two ways: either by a crank mechanism, as in an internal combustion engine, or by means of a special swinging bearing, which is colloquially often called “drunk” because of the peculiarities of its movement.
The second, shock piston returns to its original position due to the energy of the rebound. Therefore, the drill itself, which does not rest against the wall, practically does not move in the longitudinal direction. By resting it against the wall, you can get a stable rebound and the work of the whole mechanism. At the same time, the rotation of the drill can occur by gearing.
In detail about the device of a puncher
The market has a huge selection of rotary hammers, but how to choose the right tool that you need?
Device Selection Criteria
A tool such as a rotary hammer may be needed to perform a variety of tasks. If you live in a house or apartment with concrete or cinder block walls, then a puncher is your first assistant. He “feeds” a professional builder, helping in a wide range of works. It will be useful to both an electrician and an installer of air conditioning and heating systems. When building your own home or when repairing an apartment, you can’t do without a punch. You can mix the mortar, grind the channel for wiring, mount profiles for drywall or insulation.
Therefore, it is so important to consider what the unit will be used for. The builder needs a powerful professional barrel-type apparatus, while an electrician working from a ladder, on the contrary, needs a compact but resourceful model. Below are the selection criteria for the punch, so that the user can purchase a model for their needs: for work, apartment renovation or one-time use.
The impact force of the punch is the first parameter that you need to determine. The harder and more rigid the material, the greater the impact energy required from the tool. It is measured by the SI system in joules. Cope with old concrete, drill a hole in the wall with a diameter of 30 mm can only powerful machines. Their impact energy can reach up to 30 J. True, a large impact force causes no less strong rebound, but in powerful devices it is compensated by a large weight.
Low-power household units have a impact force of 0.25 joules. This, of course, is not enough. By power characteristics, such tools come close to professional impact drills. However, this disadvantage can be compensated by the small size. If you are not going to drill holes larger than 6 mm and only in brick, then half a joule is enough.
Normal household tools have impact strength in the range from 1.2 to 3 J. If you only drill with a blow and only occasionally remove tiles from the wall, then a parameter of up to 1.8 J will suit you, if you plan to ditch and break concrete, then take at least 2.5 J.
The design of any hammer drill has a direct relationship: the more powerful the unit, the heavier it is. The heart of the instrument. The electric motor. Provides both impact force and rotation speed. Therefore, a more powerful engine has larger dimensions and weight.
Household rotary hammers weigh from 2.2 to 3.5 kg. This is perhaps the best weight for the home. Powerful corner models supporting bore 18 mm in diameter weigh even more. 7. 9 kg. Remember that large, heavy units are difficult to work for a long time. If you are not going to often use a hammer drill as a chipper for hard concrete, it is better not to choose models heavier than 3.5 kg.
Engine power and shaft speed
Although the puncher does the work, which in terms of force seems more powerful than the work of a drill for drilling holes, for this it requires less rated power. Electric motors of punchers produce from 480 W to 2 kW. Among them, several subtypes can be distinguished:
Low power rotary hammers: from 480 to 800 watts. These are the very models for household and everyday life. Such power is quite enough for homework, especially if a high-quality assembly will be attached to it.
Medium power devices: 800. 1000 watts. They are used for a larger volume of work and their higher complexity. There are already more professional models in this class.
Powerful drilling and crushing machines: from 1 kW and above. These tools are used in construction, breaking concrete, drilling hard stone and for other heavy work.
When choosing a hammer drill for specific needs, it should be remembered that power is not directly related to the impact force. In one model, a 500-watt engine will provide more than two joules upon impact, and in another, a 600 W motor will barely produce 1.5 J. The impact primarily depends on the parameters of the pneumatic cylinder. That is why among direct competitors it is better to choose a less powerful, but better model, capable of delivering a strong blow.
The engine speed ranges from 250 to 2500 rpm. Since the puncher performs the main work with the percussion mechanism, the rotational speed is less important here than in drills and screwdrivers. Rotation needs more to remove waste while drilling material. It is enough if the speed is from 800 rpm or slightly higher. Remember that too high a rotation speed of the drill will lead to its accelerated wear.
In punchers, there are three operating modes, each of which is used in the right conditions:
- Drilling This is actually a drill mode. They are equipped with entry-level punchers, which are supposed to be used in everyday life as universal devices. In this mode, the use of a drill is meaningless. Therefore, you need either a quick-clamp adapter or a replaceable three-jaw chuck that will allow you to fix the drill. Over, in the version with the adapter, beats during rotation will be present, which will negatively affect the accuracy of the hole.
- Drilling with a punch. The main mode, which is used for drilling holes of different diameters. The impact of the drill into concrete crumbles and breaks it, and rotation removes the breakaway particles and brings them out.
- Drilling without impact. Also called swotting. In such works, not a drill is inserted into the cartridge, but a chisel, chisel, spatula or spade. In this mode, the punch becomes a miniature jackhammer. In household models, manufacturers recommend using a hammer drill in the slotting mode for no more than a quarter of the total time working with the tool.
If we talk about the combinations of these operating modes, then even in low-cost low-power devices there are all three modes. Apparently, the function of clean drilling is still positively perceived by users who want to choose a universal tool.
In rotary hammers with an angular arrangement of the engine, the impact function is made non-disconnectable. Only the last two modes are present. Manufacturers naturally believe that large, powerful devices will not serve as drills. This is simply inconvenient. The large weight and dimensions, as well as the use of the SDS-max cartridge, led to the fact that such devices can only drill with a blow and hammer.
In punchers, a special cartridge is used paired with a drill. The drill with a special shank, where the longitudinal grooves are located, is firmly held in the cartridge and cannot turn. Because of this, manufacturers even had to include a special locking clutch in the design, which would turn off the mechanism when the drill jammed in the hole.
The SDS-plus standard chuck is placed on longitudinal small and medium power rotary hammers. It is designed for the installation of drills and other equipment with a shank diameter of 10 mm.
The SDS-max standard chuck is designed for drills, chisels and larger diameter peaks. 18 mm. In heavy professional punchers, this cartridge is placed due to the dimensions of the installed tools.
Hammers that are used at home, when you need to drill a couple of holes from time to time to hang a shelf, are made according to the classic drill. The motor shaft is parallel to the axis of rotation of the chuck and drill. Such power tools are also called classic or longitudinal. To transfer torque to the translational motion, either a gear with a connecting rod or a more often swinging bearing is used.
Rotary hammers with a horizontal arrangement of the engine (barrel, angular) have a more powerful and overall electric motor. Mounted at an angle, it reduces the length of the unit with its, as a rule, greater power. The piston is driven by a full crank mechanism, also designed for long-term use under load. With this arrangement, the center of gravity is more successfully located. Therefore, although barrel drills are more mass, it is quite convenient to work with them.
However, experienced craftsmen prefer to have two perforators: one less powerful classic layout and a heavy corner. The thing is that it is unsafe to work with a heavy unit while standing on the stairs. It’s inconvenient for them to carry out small work because of its still large weight and large diameter drills chambered for SDS-max. Therefore, everyone decides for himself which option is best for him. The vertical or horizontal arrangement of the engine.
The more expensive and perfect the punch, the more it is equipped with various additional functions, well-equipped and protected. Without them, the punch will perform its functions anyway, but with them. Easier, faster and more convenient. Among these features, we highlight the main ones:
- Soft start of the engine and protection against an overload;
- Depth limiter;
- Keyless three-jaw chuck. Either as an adapter, or changing the native SDS-plus;
- Safety lock-up clutch;
- Reverse rotation mode of the electric motor;
- Cord longer than 3 meters;
- Special springs damping vibration during impact work;
- Plastic case with a minimum set of drills, blades and chisels.
Renowned manufacturers of rotary hammers are trying to make their equipment not only reliable, but also convenient. The ergonomics of the handle, the noise generated by the engine. All these parameters will be better with more expensive and advanced models.
In most cases, rotary hammers are powered by a voltage of 220. 230 V. But what if there is no outlet nearby, and electricity has not yet been supplied. At one time in the road and construction works used powerful drilling machines with a gasoline drive.
However, today technology has stepped far forward and allowed to store electricity in batteries. Modern batteries charge quickly, hold a charge for a long time and are capable of delivering power comparable to power from a wall outlet. The issue of autonomy is thus solved very simply, especially if the scope of work is small.
True, the cordless rotary hammer has its drawbacks: more weight, limited power, limited battery life. Alas, you have to pay for everything.
Which punch to choose for the house, you decide, and only you. Having defined your tasks, you understand that it would be nice to find the perfect hammer drill: cheap, powerful, compact, reliable, and all this in one device. Unfortunately, this does not happen. Therefore, here are some final tips for doubters:
- If you have money and storage space and a constant need for drilling, get two perforators: one weaker with a linear layout and more powerful with a corner.
- If the budget is average and you want to do everything with one tool, turn your eyes to medium power and good reliability. A plus will be the ability to easily change cartridges.
- If funds are limited, it is better to take a more expensive, but better model of lower power than a cheap device more than 1 kW. Quality can sometimes compensate for a lack of power.
And of course, do not choose thoughtlessly! If your work front is four holes of 8 mm in six months, there is no point in spending money on an expensive unit. In such conditions, even a budget little-known brand punch will last a long time.
3 best tools for widespread use in everyday life
Domestic use only in appearance seems simple and undemanding. In fact, the tool can be presented with a variety of requirements when choosing. After all, it is one thing to remove several chopped tiles from the wall in the kitchen, and another to use a hammer in the construction of your house. We offer top 3 models for home use that will not make you disappointed in them.
Well-known company, quality assurance, assembly. China, but with the control of the production process. With a power of 780 watts, the unit provides a little more than three joules of impact force. than enough for any homework. Low engine speeds may seem like a disadvantage, but in fact this is a plus: the engine will not overheat, and the drill will fail faster.
Bosch PBN 300 FRE
The “green” Bosch line is not as expensive as the “blue” one, but its reliability is also beyond doubt. This hammer drill is slightly heavier than the previous one, it has a power of 750 watts and a power of 2.8 J, which is also a pretty decent indicator. The complete set of the case in which the model is delivered is encouraging. There is everything to start work.
The products of this company are traditionally considered one of the best. At 780 W of engine power, the device “hammer” with a force of only 2.4 J, and drills at a speed of 1100 rpm. These are the lowest indicators among the given models. But the indicated rather modest characteristics are more than compensated by workmanship and reliability during a long period of uptime.
With proper care and proper operation, the hammer drill can last for many years. Observing these recommendations, you can easily save your puncher from adverse effects:
- When working, you need to regularly lubricate the drill shanks to reduce wear and facilitate the operation of the mechanism. Viscous greases are prone to tar formation under the influence of temperature and air. It is best to use either liquid lubricant or graphite, not afraid of strong heat.
- To protect against building dust, you can cut out a safety glass from a plastic bottle and put it on the punch behind the cartridge. If the dust is still clogged, it can be removed by blowing air vents on the compressor. But sometimes the hammer must be disassembled by removing the cover and cleaned inside. The amount of contamination will help increase the use of a special construction vacuum cleaner.
- When disassembling a hammer drill, pay attention to the brushes of the commutator motor: when worn, they must be replaced on time.
If the punch is treated with care, then a good technique will last for many years.
Using a punch is a matter that everyone can do. Choosing a high-quality and inexpensive to work with is already more difficult, because in the market of power tools, eyes run wide from the variety. Taking into account the correspondence of criteria that are important to you will help you choose a good hammer drill and not be disappointed in it.