How to use the mode?
Under impulse loading of the screwdriver, uneven rotation of the spindle with characteristic jerks is observed. This allows you to significantly increase the torque, as well as the load power without damaging the threads and the spline of the fastener. Unlike an impact drill, it delivers a powerful and instant impact that propels the screw or nut forward.
If during operation there is increased resistance (for example, if there is rust on the fasteners), the screwdriver automatically switches to pulse mode. The torque force increases by 3-4 times, the angular speed of rotation of the coupling decreases. Depending on the specific model, the boost speed can turn on automatically or start when resistance appears.
Working with the tool does not differ from using a classic screwdriver - you should install the shank of the nozzle into the chuck, then attach it to the fasteners and start the device. Drilling or screwing in is jerky, therefore the handle of the device must be held very tightly, it is recommended to use gloves.
Brand Description
DeWalt is an American manufacturer of quality power tools and wrenches are not the only category they produce in their factories. Production is scattered almost all over the world, there is in China, Mexico, Germany and other countries. The company was founded back in 1924, during this time it was possible to achieve high quality products, to introduce its own developments on the market. All products, including wrenches, are of high quality, reliability, and affordable cost. Moreover, they meet international standards, therefore they are successfully used in our country.
Impulse screwdriver device
Now that you know how the impulse screwdriver differs from the impact driver, you can consider the device of the first. The equipment consists of the following units:
- speed regulator;
- DC motor;
- planetary reductor;
- battery;
- load limiting mechanism.
A spare battery and a mains charger are available as additional devices. The engine is made in the form of cylinders with permanent magnets inside the housing. The anchor is located on support bushings, which are made of brass. The armature itself is based on electrical steel with good magnetic permeability. Insulated wire windings are placed in the armature grooves. After an equal number of turns, the winding goes to the collector plate.
To ensure contact, the brushes are spring loaded, they are isolated from the motor housing. Once you understand what an impulse screwdriver means, you can familiarize yourself with its device. It provides for the presence of a planetary gearbox. This unit is made in a separate case. The composition includes the following elements:
- sun gear;
- ring gear;
- drove;
- satellites.
The parts of the gearbox can be metal or plastic. For a complete understanding of the operation of the gearbox, the location of the individual parts should be clarified. For example, a ring gear has the form of a cylinder with teeth inside. Satellites move along them.
How to choose?
When choosing a model of a screwdriver, one should take into account the specifics and regularity of work. If you plan to use the tool often and intensively, then brushless professional models with a battery should be preferred. If you need a device for rare household chores (screwing a cornice, assembling furniture or hanging a shelf), then you can choose models with low power and mains supply
What to look for when buying:
- weight and compactness of the model;
- maximum torque;
- automatic or manual switching on of the pulse mode;
- ergonomics of the handle, rubberized elements on the contact parts of the body;
- the ability to switch speeds;
- type of battery, its capacity.
If you already have special devices for working with fasteners, for example, a conventional screwdriver, an impact drill, and a wrench, then the models with a pulse mode are not necessary. Most often they are used in construction, car workshops, where it is necessary to work with stuck and rusted fasteners.
Instructions for use
Before starting to work with the tool, the manufacturer recommends that you always first check it for serviceability. To do this, it is enough to inspect for obvious damage. If, when plugging into the network, there is a smell of plastic, or smoke comes out, the wrench is immediately turned off. All moving parts must be well connected, if you have experience, it is better to see if all the nodes are assembled correctly. If repairs are being made, then in the absence of experience, it should be entrusted to professionals or it is necessary to follow strictly the instructions.
In the next video, you will find an overview of the Dewalt DCF899 brushless impact wrench.
Range
DeWalt are electric, impulse or impact wrenches that can weigh from 2 to 5 kilograms.
Cordless tools are popular because they are self-contained and do not require a power source to be used. On such units there is a regulator responsible for setting the power and a mechanism that adjusts the number of revolutions
Their work is based on impulse rotation, and when choosing, the consumer should pay attention to:
- wrench power;
- battery capacity;
- torque.
The last indicator in the models of this manufacturer is presented in the range of 100-500 Nm. The diameter of the nuts that can be tightened depends on it. Battery capacity and operating voltage indicate the performance of the equipment used. One of the brightest representatives of this class is the DeWalt DCF 880 M2 with an XR Li-Ion battery, a maximum torque of 203 Nm and a number of strokes per minute of 2700. The weight of the unit is 1.5 kilograms.
Electric models can be more powerful, they work quieter by rotating the existing drive, which is converted into impulses, shocks. The direction of movement set by the user depends on whether the nut is unscrewed or twisted. Such units can even be used with elements whose thread size reaches 30 mm.
Most of these models have a power regulator. They demonstrate high performance and are powered from a standard network. The torque is adjustable in the range from 100 to 500 Nm, on impact models the frequency per minute is 3000 strokes.
To prevent the engine from overheating, a fan is provided in the design. There are fasteners on the body for additional equipment
You should definitely pay attention to DeWALT DW294, the total weight of which is 3.2 kilograms. This model is in demand for a maximum rpm of 2200
This is a percussion unit that makes 2,700 impacts per minute, while the maximum torque is 400 Nm. It can work with a maximum bolt diameter of 20 mm.
