How to pick a jackhammer
Modern construction, reconstruction and repair work in buildings cannot be imagined without the destruction of various structures. The strength of concrete, masonry thickness of several bricks does not allow for dismantling with manual tools with sufficient speed indicators. Therefore, for the destruction of structural elements are widely used devices such as a jackhammer and a concrete breaker. These types of tools are similar in design and principles of operation, but differ significantly in characteristics and applications.
- 1 Purpose of a jackhammer, and its difference from a betonolom
- 2 Types of jackhammers
- 3 Criteria for choosing a hammer
- 4 Rating of popular and effective devices from reliable manufacturers
Purpose of a jackhammer, and its difference from a betonolom
The jackhammer is one of the most productive shock-type devices for dismantling and other work related to the destruction of materials of different strengths. With it, stroking or removing, for example, screeds on the floor - can be carried out much faster than with the use of such a familiar tool as a punch.
The main characteristic for choosing a jackhammer is the impact energy of the striker. By this parameter, the tools are divided into categories.
- The first is the strike energy of the striker up to 30 Joules., the frequency of power pulses is up to 45 per second (Hz). Used for dismantling coatings and structures of medium strength (brick, asphalt).
- The second - up to 40 J, with a frequency of up to 34 Hz. Used for general works, including grooving of grooves, removal of screeds.
- Third - up to 45 J, with a frequency of up to 20 Hz. It is used to work with durable materials.
- Fourth - over 50 J, with a frequency of up to 24 Hz. This tool work on complex material, mainly in the vertical direction.
Important! It is worth noting: even the tool of the most powerful category is not recommended for the dismantling of reinforced concrete slabs, floors,monolithic casting with low sand content in solution. Concrete breaker is used for this purpose.
The main difference between this instrument in terms of weight and dimensions and impact energy. Betonol at times heavier and more dimensional than a jackhammer. Much more impressive and indicators of impact energy. In the breaker, it is at least 2-2.5 above the value that the jackhammer is capable of showing.
Concrete breakers with significant indicators of impact force have a design that limits the operator’s freedom of action for guaranteed high application safety. So, most manufacturers in their top models use a simple mechanism that allows you to turn on the device only in a vertical or strictly horizontal position.
Types of jackhammers
The construction sphere is not distinguished by the complexity of the rules: the more powerful the tool, the faster the work is carried out. However, if we consider a jackhammer, its choice is based not only on the device’s mass index and impact force, but also on the features of mechanics and energy source. By weight, the tool is divided into three categories.
- Lightweight, weighing 5-6 kg. Such a tool is recommended to be used where freedom of action is needed (in cramped conditions, when working at an angle, at points of convergence of walls, and so on). Easy jackhammer is used when working at height.
- Middle class tool (5-10 kg) shows the greatest performance when working in a vertical, horizontal direction.
- Heavy jackhammer (up to 30 kg) it is perfectly applied when working with soil, foundations.
Regardless of the class, the tool is completed standard peak set. The nozzle can have different sizes. The kit includes a peak-crowbar for loosening or breaking, a spatula for splitting and edge-leveling operations, a chisel for chipping and cutting of material. Depending on the conditions existing at the site, you can choose the type of tool that will show the greatest level of convenience and safety.
The source of energy in a jackhammer of this class is the electric motor. The mechanics of power transmission are simple: the rotation of the rotor through the cam assembly is converted into reciprocating movement of the striker. Electric jackhammer has the following advantages:
- low weight;
- it is easy to choose the tool of the necessary power;
- A simple gearbox is used to increase the impact energy.
Electric jackhammer shows the best results in finishing work, when removing old coatings. However, this tool has disadvantages:
- cannot be used in premises with a high level of fire and explosion hazard due to sparking of the rotor contact brushes;
- may fail or show abnormal operation of the engine in high humidity.
Electric tool always depends on energy source. Therefore, it does not make sense to choose a jackhammer of this class for construction work in buildings without a 220 or 380V network.
Rechargeable Electromy useful where there is no power network. However, devices of this class can not show an acceptable operating time, characterized by reduced rates of impact energy. In addition, the battery power significantly increases the mass of the instrument. The use of a battery jackhammer is rational only for one-time, emergency work.
The energy source of this type of tool is internal combustion engine. Thanks to this gasoline jackhammer:
- has a slightly larger mass compared to electric;
- not tied to power distribution points, fully autonomous;
- may show a significant level of impact energy, especially with the use of gearboxes.
However, gasoline devices present a fairly significant list of drawbacks.
- Hazardous, toxic gases do not allow to work in confined spaces.
- There is a constant danger of spillage and fire.
- Significant noise level.
It is convenient to work with a petrol bump stop outdoors. Such a tool is a good and economical choice if you need to remove asphalt, pierce sleepers, and make landings under the pile foundation.
Air hammer, depending on the power, it happens two types:
- with the transfer of momentum by the expansion of air inside the piston chamber;
- working on volumetric expansion, supplying air to the diaphragm chamber with a stem.
Regardless of the principle of operation, the pneumatic tool has a key feature: it requires additional equipment.. The minimum set is an air compressor.It can be complemented by strapping elements that increase the continuous operation time and provide other benefits. The compressor tool has the following advantages:
- has the smallest mass in comparison with other types of jackhammers;
- the compressor tool is absolutely fire and explosion proof;
- in some cases, you can significantly save money if you use a homemade receiver and other elements of the compressor strapping;
- operating noise is minimally achievable, since the supercharger, in most cases, is far away.
The main disadvantage of the pneumatic tool - need for a compressor, a source of energy for him. However, with the large-scale use of this type of jackhammers, this minus is leveled by amenities. When organizing air control panels, to which several units of a tool are connected, it is easy to organize comfortable work of a group of operators with the help of one installation.
On a note! Similar features and has a hydraulic jackhammer. However, this device has the disadvantage of working fluid (usually oil) due to the possibility of leakage,due to seal failure or hose damage. And it serves as an additional source of fire danger.
Criteria for choosing a hammer
High energy charge and a large enough mass of individual devices make you pay attention not only to the purely technical characteristics of jackhammers. Evaluated and on such non-obvious factors as ergonomics and layout.
As mentioned above, jackhammers are not recommended to destroy reinforced concrete or cement monoliths with a low content of sand in the solution. Carrying out such work will not only lead to poor performance, but also cause high wear and tear, and therefore the need to spend on repairs.
Choose the optimal model you need as recommended by the manufacturer. If you need to get a guaranteed result, it is recommended to research thematic forums or ask the advice of experienced builders.
Estimating the weight of the jackhammer and the size of the device is a purely individual process. The tool is selected on the basis of habits, mode of operation (activity time - rest), the usual indicators of free space for manipulation. However, you should pay attention to the weight distribution apparatus. The closer the center of gravity is to the leading arm, the less fatigue accumulates with the necessary movements of the tool..
All materials in the design of the device should have as can be more durability and reliability. For the elements of the gearbox is not allowed to use plastic. But some manufacturers do not know about it. Therefore, each product before buying should be investigated as thoroughly as possible so as not to encounter a breakdown literally in the first hour of work. The main thing is not to save on the tool of reliable brands.
The constructive solution of the jackhammer should provide zero deviation of the tool axis at impact and its maximum possible rigid fixation in hand.
- The handle of the hammer should have a straight cut in the place of the grip.
- The grip zone should be located on the axis of application of the impact pulse.
- If the tool has two handles (heavy, betonolomy) - they should be located on the same line, perpendicular to the axis of impact, with the arms held at an equal distance from the center.
Any handle has trigger button. The location of this element must be such that the grip is not weakened for pressing or switching.The same applies to any regulatory bodies. None of them should cause the need to switch attention or change the mechanics of control tool.
Rating of popular and effective devices from reliable manufacturers
The modern market offers hundreds of models of jackhammers. However, the highest sales volumes are shown by three brands. This is Japanese Makita (often the instrument is assembled in Romania), German Bosch with factories all over the world, domestic Interskol, which has an attractive cost and impressive characteristics.
Makita is not for nothing considered the most desirable tool of many builders and home craftsmen. This jackhammer has almost a maximum of attractive features. Among them, smooth control of engine speed, automatic adjustment of the rigidity of the material, the possibility of grooving the grooves with the desired parameters by setting the nozzle at varying angles.
The ergonomics of the device thought out to the smallest detail, but it is worth noting unsuccessful weight distribution. Despite the impact rate, which allows to refer the model to the first classification category - its geometry is typical for the third.The power of the device is 550 W, the energy of the striker is 2.8 J, the frequency of the pulses is from 2000 to 3500 Hz, the mass is about 3 kg.
- excellent efficiency, low energy consumption due to electronic engine control;
- reliable chuck made of steel with fast mechanics of nozzle changing;
- convenient knob frequency control;
- double insulated electrical wiring;
- low mass;
- 12 nozzle positions;
- long wire
- weight distribution, the most convenient to work in a horizontal plane;
- handle design that violates the force distribution scheme.
Bosch GSH 11 VC
The German brand Bosch is able to lead the ranking of manufacturers of the best devices with perfectly balanced characteristics. The Bosch GSH 11 VC electric jackhammer was no exception.
Model refers to first impact energy category of 23 j. The device is quite heavy - 11 kg. However, the design complied with all the rules of ergonomics. Perfect weight distribution, the location of the center of gravity, grip and direction of impact will allow the tool to operate without accumulation of fatigue for a long time.
- powerful engine;
- significant impact force;
- the possibility of long-term work (engineering solutions) at maximum loads;
- perfect layout;
- reliable cartridge with the ability to quickly change the nozzle;
- effective engine ventilation system;
- convenient location of switches.
- electronic engine control;
- 12 chisel positions;
- low vibration;
- adjustment of force of blow;
- indication of the need to change the motor collector brushes.
- not long cable;
- high mass.
The main characteristics of products Interskol - reliability, simplicity, reasonableness. It is worth noting that the company carefully researches the market and develops a tool with successful structural and engineering solutions.
As an example, we can consider the model M-25. Comfortable handle allows you to effectively manipulate the tool in a horizontal position. However, Interskol M-25 excellent weight distribution due to the location of the engine almost on the axis of impact. In addition, the starting button is also shifted. As a result, the device is very easy to work, despite the relatively high mass of 17 kg. The impact energy is 25 J, the frequency is 1400 mm, the consumed electric power is 1500 W.
- reliable vacuum compressor mechanism;
- steel 30 mm cartridge;
- no-stroke system with no moving parts wearing out;
- the possibility of long work at the limit of power;
- successful weight distribution;
- rubber pads on the handle;
- elaborate ergonomics, great reliability.
- the mass is much higher than competitors due to the use of a sleeveless system;
- no impact force adjustment.