Comparison Dremel 4250-6/128 vs Dremel 8220-5/65

The electrical power consumed by the tool during normal operation. Usually, the characteristics indicate the power at the maximum speed / frequency of movements of the working nozzle.

Usually, the higher this indicator, the more intense the tool can act on the material being processed, the better it is suitable for difficult conditions (large volumes of work, hard materials). At the same time, note that high power significantly affects energy consumption; in mains-powered models (see below), this puts strain on the wiring, and in battery-powered models, it requires the use of bulky and heavy batteries and significantly reduces battery life. Yes, and this parameter significantly affects the dimensions, weight and price of the tool itself. Therefore, it is worth choosing a model according to power consumption, taking into account the specifics of the work for which it is planned to be used: for example, it hardly makes sense to purchase a high-performance professional tool for minor repairs around the house or in the country.

Specific recommendations on the optimal power values, depending on the type of tool and the purpose of its use, can be found in special sources.

- Reverse. Possibility to change the direction of rotation of the working nozzle of the tool. The use of reverse depends on the type of tool and the type of work for which it is used. For example, when drilling, this function can be useful for releasing a jammed drill. And in screwdrivers (see "Interchangeable heads") a change in the direction of rotation is almost mandatory - otherwise it would be impossible to switch the tool from twisting to loosening and vice versa.

- Speed controller. The ability to smoothly change the speed of movement of the working nozzle (frequency of rotation or vibration). The adjustment itself is used to adjust the tool for different types of materials and work - for different cases, the speed is different. But smooth tuning is good because it allows you to set the required speed as accurately as possible - there are no strictly fixed adjustments in such models, and the operator can choose any option from minimum to maximum. True, a certain skill is required for the effective use of such a tool, but this problem can hardly be called serious even for beginners.

- Maintain momentum. A function that allows you to maintain a constant speed of rotation of the nozzle, regardless of the load on it. Without special adjustment, at a constant engine power, the rotational speed inevitably drops with increasing load and increases with...a decrease. And the revs control system monitors the resistance on the nozzle and, if necessary, changes the power in such a way that the rotation speed remains constant. This has a positive effect both on the quality of work and on the service life of the nozzles and the entire tool.

- Soft start. The moment of starting is one of the most difficult in the operation of any electric motor. When the power is connected directly, in the first moments after the start, a high power flows through the windings, which leads to voltage surges in the network; in addition, the beginning of the movement occurs very abruptly, and this is fraught with jerks of the instrument, with the risk of releasing it from the hands with corresponding unpleasant consequences. The soft start function reduces the described troubles, if not to zero, then to a minimum: special circuits limit the starting power and ensure a soft and safe start of movement.

- Brushless motor. The presence of a brushless (brushless) motor in an electric tool. Such motors are noticeably superior to traditional collector motors in terms of efficiency, which makes it possible to significantly reduce energy consumption without sacrificing power; this is especially important for cordless tools (see "Power Source"), where this feature is predominantly found. In addition, brushless motors are less noisy and generate virtually no sparks during operation, making them ideal for working in high fire hazard environments. Their main disadvantages are traditional - the complexity of the design and high price.

— Backlight. The tool has its own lamp to illuminate the place of work. This feature is especially useful when working in low light conditions or in hard-to-reach areas that are otherwise difficult to illuminate. Note that in this case, it is the embedded system that is meant; some models may be equipped with portable lights as separate units, but such lights do not count as lights.

- Display. Own display in the design of the multifunctional tool is designed to visualize customizable parameters, display the battery charge level and display all sorts of related information. The specific implementation of the screen depends on the level of functionality of a specific instrument model.

- Connecting a vacuum cleaner. Possibility of connecting the vacuum cleaner directly to the tool. For this, a special pipe is usually used, one end of which is led to the place of processing, and the actual hose from the vacuum cleaner is connected to the other. Thanks to this, the work becomes much “cleaner”; True, the vacuum cleaner is far from always 100% able to remove sawdust and other waste, but in any case, it at least simplifies subsequent cleaning. The hose nozzle is usually made removable - this allows you to reduce the overall dimensions of the tool in cases where the vacuum cleaner is not needed or is not within reach. Note that before buying a model with this function, you should pay attention to its compatibility with the specific vacuum cleaner that you plan to use.

— Keyless replacement of nozzles. The presence of a clamping tool in the design that allows you to replace working nozzles without using a key. There are many varieties of such clamps, differing in the procedure for use, but they all have one thing in common: the work with the mount is carried out by hand, without the use of keys or other additional devices.

The total number of working attachments supplied with the tool.

The abundance of attachments allows the machine to be used with various materials and for various types of work. At the same time, this parameter significantly affects the cost. Therefore, when choosing, you need to proceed from how important a variety of possibilities is for you - so as not to overpay for extra nozzles that turned out to be useless in fact.

Note that this item is indicated only for engravers (see "Device") - for models of other types, specific types of nozzles are given in the corresponding item (see below).

The type of power used by the tool to operate.

— Network. Powered by a conventional household network of 230 V. This option allows you to create units of almost any power — within the range that can be useful for a hand tool. At the same time, such models, other things being equal, weigh less and cost less than battery ones, and when working with them, you do not need to monitor the state of the battery, risking being left with a “dead” tool at the most inopportune moment. Their main disadvantages are dependence on sockets and the presence of a power cord, which limits mobility, can create inconvenience and requires extra care (so that the cable does not get under the working nozzle).

— Battery. Powered by its own built-in battery. Such a tool is extremely mobile and easy to use — it does not require a network connection, which allows you to work even if there are no outlets nearby. And the absence of a cable has a positive effect on convenience and safety. On the other hand, the power of battery models is generally lower than that of mains ones, and the battery itself significantly increases not only the price, but also the weight and dimensions of the unit — modern tools consume a lot of energy, which means that they need appropriate batteries. In addition, the battery life is limited, and when the charge is exhausted, the battery will have to be charged, which takes time and the ava...ilability of power. This disadvantage in some models is compensated by the presence of a spare battery in the delivery set (see "Replacement battery"), but only in part — the second battery increases battery life, but does not eliminate the need to charge dead batteries. In view of all this, it is worth paying attention to models with such a power supply only when the ability to work without sockets is critical for you.

— Batteries. Models powered by replaceable AA batteries and some of its derivatives. A similar way of power supply is implemented in low-power tools in the manner of compact rotary engravers.

The number of batteries supplied with the respective tool (see "Power Source"). Also, this item may indicate the presence of a built-in battery.

The most popular configuration option with a battery in our time is 2 batteries. This provides additional benefits, which are especially convenient for long continuous use of the tool. So, when the charge of one battery is exhausted, you can quickly change it to another; while one battery is in use, the other can be charged. This minimizes or eliminates interruptions in charging. Single battery kits are not particularly common: they are mainly entry-level tools designed for small amounts of work, when charging breaks are quite acceptable.

In addition, quite a few modern cordless tools come without batteries. This configuration assumes that the customer himself will purchase batteries at his discretion (many models are compatible with several brands of batteries at once). In addition, this option may come in handy in case the battery is already on the farm. This happens quite often, since many well-known manufacturers use universal batteries suitable for different types of branded power tools. So a battery, for example, from a previously purchased electric jigsaw or grinder may well be compatible with an engraver, a renovator of the same company.

As for non-removable batteries, this is a rather rare...and specific option. Such tools turn out to be as compact as possible, but the batteries themselves cannot be quickly changed - so you will inevitably have to take breaks for charging during work. Therefore, this method of supply is typical for low-power instruments. In them, small size is more important than a long period of continuous operation, in addition, a low capacity allows you to achieve good autonomy even with small sizes (and, accordingly, capacity) of batteries.

Nominal voltage of the battery supplied with the appropriately powered tool (see above).

This parameter is usually selected by the manufacturer in such a way as to optimally match the specifications of a particular model. Therefore, in fact, it is more of a reference than really meaningful. However, in some cases, voltage information can be useful — for example, if you are looking for a spare battery or want to replace a failed battery.

The type of battery supplied with the rechargeable model (see "Power Source").

— Ni-Cd (nickel-cadmium). The most "old" option found in modern power tools. It is distinguished by high reliability, resistance to temperature extremes and good charging speed even with high capacity (which is important, given the "voracity" of the power tool). The main disadvantage of this type of batteries can be called a pronounced "memory effect" — a decrease in battery capacity if it is set for charging without being completely discharged. In addition, Ni-Cd cells are considered environmentally unsafe. Nevertheless, they are still widely used in tools — not least due to their low cost with decent performance.

— Ni-Mh (nickel-metal hydride). Such batteries were created as a development of the nickel-cadmium batteries described above. Retaining all the main advantages of their predecessors, they are at the same time devoid of most of the shortcomings — in particular, they are practically not subject to the memory effect. Of the own shortcomings of this option, it is worth mentioning a slightly lower durability and higher cost than the original Ni-Cd.

— Li-Ion (lithium-ion). A type of battery originally developed for use in portable devices; however, with the development of Li-Ion technology, it has also been used in power tools. The main advantage of such batteries in this case can be called a high capacity with small dimensions and weight. It is also worth noting...that they are not subject to the memory effect and are able to charge quite quickly. On the other hand, this option is not without its drawbacks — this is, first of all, sensitivity to too low or elevated temperatures, as well as a high price.

The capacity of the battery that the tool with the corresponding type of power is equipped with (see above).

Capacity is essentially the amount of energy a battery can store. The more powerful the device, the more energy it needs to work and the higher the battery capacity should be so that it does not have to be charged too often. At the same time, capacious batteries have a large weight and dimensions, which significantly affects the convenience of work. Therefore, the power of the battery tool is relatively low — otherwise, too bulky batteries would have to be used.

To some extent, this parameter also determines the time that the tool is able to work without recharging. However, taking into account the fact that different models can noticeably differ in power consumption, it makes sense to compare with each other by battery properties only tools with very similar specifications — and even then very approximately.

Note that the same tool can work with batteries of different capacities — it is enough that they are compatible in terms of connectors and operating voltage. However, if you are looking for a spare battery or a replacement for a failed battery, it is best to choose a variant of the same capacity as the original one.

The time to fully charge the battery that the tool is equipped with from a standard charger (when using other batteries or a “non-original” charger, this time may vary both in one direction and in the other).

For battery tools in general, see "Power source". And charging time data gives you an idea of how you'll need to organize your workflow and how long breaks you'll need to charge your batteries. The specific duration of the process will depend both on the capacity of the battery (all else being equal, a more capacious model takes longer to charge), and on the technologies used by the manufacturer to increase charging efficiency.

Also note that the specific meaning of this parameter also depends on the number of batteries in the kit. Recall that there are often several of them at once (see "Batteries in set"), and while one battery is working, the rest can be charged. This allows you to reduce interruptions to a minimum, and even completely do without them. But if there is only one battery, charging breaks will inevitably be required in full. This is especially true for tools with a built-in power source (in models with replaceable batteries, the situation can be corrected by purchasing additional batteries).