Review of the Kress KU801 cordless angle grinder

The main characteristics of the tool are presented in the following table.

The angle grinder in question is equipped with a brushless motor and is distinguished by its large size and significant weight. In addition, the presence of a comfortable handle with a sophisticated internal anti-vibration structure gives the tool even more reliability and high-quality performance.

The weighty, large body is almost entirely covered with durable rubber, which prevents the tool from slipping in your hands. The color scheme is stark black with orange Kress lettering. An acquaintance of the author called this design intimidatingly impressive: “It looks like Darth Vader.” Well, everyone has their own associations.

The machine is turned on using a standard slide switch. This slider is located on top, on the side opposite the disk. To start the motor, you need to move the switch forward and slightly down so that it locks into the locking recess.

The spindle lock button is in the standard position, the top of the metal gear housing. A fairly strong spring under the button and high sides are noticeable, providing protection against accidental pressing.

This tool is equipped with an intelligent system that prevents the engine from automatically starting when the battery is replaced. Sometimes it happens that the battery is discharged during operation, and when you insert a new battery, nothing happens. This function allows you to avoid such situations: the angle grinder engine will not start until you return the switch to the “Off” position. and do not turn on the instrument again. This is an important protection against careless handling of the tool. Without such a function, using a cordless angle grinder can be dangerous.

Despite the lack of a declared soft start function, the engine does not start instantly. This prevents possible “drifting” or twisting of the angle grinder. The manual also recommends running the tool without load, waiting until it reaches maximum speed before starting work.

Regarding the brake, which is also not specified in the documentation, the sensations remain approximately the same. This angle grinder appears to have an electric engine brake. It is difficult to imagine that a heavy and spinning tool would stop so quickly without a braking system. Comparing a regular corded angle grinder with no special features to this tool when starting and stopping, the electric brake is really an important element here.

Of course, angle grinders have a brake. It is obvious that he is present. Stopping in less than three seconds versus eight seconds for a conventional angle grinder, which, as you know, does not have a braking system.

Another observation: an expensive tool works quietly at idle, unlike a budget angle grinder, which makes heart-rending squeals.

Different types of attachments and materials require different processing speeds. For example, for precise processing of dry wood or more precise sanding, it is better to use a low speed, which also reduces the risk of overheating the material. It is also recommended to cut plastic at low speeds to avoid melting. While grinding or cutting metal requires high speeds. In this case, the speed change function available on the angle grinder in question will come in handy. There are three fixed preset speeds: 3000, 6000 and 8500 rpm idle. Each speed is indicated by a green LED and numbers 1 to 3 displayed on a panel at the bottom of the handle. The required speed is selected by successively pressing the button located in the same place.

Interestingly, the grinder retains the last used speed. The memory is retained even after changing the battery, so the tool starts at the last selected speed.

No tools such as wrenches or screwdrivers are required to install, remove or modify the guard. You just need to match the protrusions of the casing with the grooves on the spindle platform, install the casing, slightly rotate it along the axis and fix the locking lever with your finger.

Interestingly, the grinder retains the last used speed. The memory is retained even after changing the battery, so the tool starts at the last selected speed.

No tools such as wrenches or screwdrivers are required to install, remove or modify the guard. You just need to match the protrusions of the casing with the grooves on the spindle platform, install the casing, slightly rotate it along the axis and fix the locking lever with your finger.

The angle grinder comes complete with detailed Russian-language instructions, which contain not only a list of safety measures during operation, but also methods for performing various tasks. Each user using an angle grinder for the first time is required to carefully study this document. It contains details that must be remembered and always observed, especially for those who value their safety. For example, it is prohibited to use a cutting wheel for rough grinding, although in some cases it may be tempting to do a quick deburring with this tool. However, this is unacceptable. It is useful to periodically re-read instructions of this kind even for experienced repairmen, like, for example, traffic rules for experienced drivers.

Attaching attachments

To fasten the equipment in the angle grinder in question, a standard spindle with an M14 thread is used, and to fix attachments that do not have their own threads, an internal and external flange is used, which is tightened with the supplied wrench.

We have prepared several attachments for different purposes, for working on wood, metal and concrete.

The inner diameter of the protective casing is 138 mm, and the height of the side is 23 mm. These dimensions allow the use of non-standard attachments with the casing, the actual diameter of which exceeds 125 mm and which are not designed to work with the protective casing on.

Most of the consumables fit safely in their place.

The exceptions were two large sanding attachments with far-reaching sanding elements: with felt flaps and a wire one, which has a flat shape rather than a cup-shaped one. Their actual diameter exceeds 125 mm, and the outer boundaries abut the inner wall of the casing. If a felt nozzle is not dangerous and you can work with such an nozzle without a protective casing, then a wire nozzle is not to be trifled with. When working at high speed, pieces of wire can break off and fly out in a variety of directions — without protection. It is better to refuse to purchase this consumable, and if you still need a wire attachment, then you can choose a consumable in the shape of a cup.

And still, no one canceled the protective mask and gloves. Sorry for the anatomical details, but pulling a thin wire out of the skin is unpleasant.

Sawing

Continuing the tradition, we will repeat the inspection of the angle grinder by cutting a steel profile and a pipe made of a non-magnetic alloy. Thus, we will find out the power of the tool, and find out whether the angle grinder is inclined to sadly reduce speed when there is a lot of resistance.

As we hoped, the tool cut through both metals briskly, with no noticeable loss of power.

Grinding

Requirements for engine power during grinding can increase manifold due to the large area of contact between the equipment and the surface, which means increased friction. But the strong engine does not give up here either; the angle grinder almost does not reduce speed even when pressing hard on the tool. Both when working with wood and when working with metal.

If you noticed, while mocking the piece of wood, we reduced the speed, because, as already noted, at low speed, grinding pliable fibrous structures is more accurate. The risk of damage to the workpiece due to careless movement or failure is also reduced.

We will carry out the final autonomy test using an old garden tank that needs to be updated: first remove the old paint, and then apply a new coating with a “radical black” color. For this task, in addition to the grinder, you can try using the grinder, which was mentioned earlier. However, the nozzle of this machine is too large for such a part measuring one meter by one meter.

The following video shows the time counter process sped up many times over. We observed that the battery lasted almost 12 minutes with the metal flap attachment while sanding metal.

Now, after testing several cordless angle grinders, it is clear that all of these tools have a battery life of about 10 minutes or a little more. This is the price to pay for autonomy.

In order for the tool to look and function well after use, it is enough to wipe it down, especially to remove dust, including traces of concrete. It is better to store batteries separately, in a warm room, and recharge them regularly.

The angle grinder in question has two air intake filters. These metal meshes are not removable, but can be easily cleaned with a brush.

For a battery of this capacity — quite fast. This is because the station in operation consumes a large amount of energy, which can vary depending on the percentage of battery charge (or network voltage), but not less than 100 W.

The Kress KU801 is a powerful, durable and reliable tool suitable for both home and professional use. Due to the absence of wires, the angle grinder provides freedom in choosing where to work, be it installation of fences or field work, where laying wires turns out to be difficult, time-consuming or impractical. It is more convenient to have several charged batteries with you than to carry a generator or charging station.

Advantages:

— High power.
— Fast charging.
— Low noise level.
— Speed adjustment.
— Keyless mechanism for fixing the casing.
— Protection against accidental starting when replacing the battery.

Flaws:

— During testing, no deficiencies were found.