Comparison Ronix 3420 vs Black&Decker BCRT8I

The speed of rotation of the working nozzle provided by the tool. Some models have a fixed rotation speed, others allow you to adjust it within a certain range (see "Number of speeds").

For different types of tools and types of work, different values of this parameter will be optimal; therefore, it is worth choosing taking into account the tasks that are planned to be solved using the tool (it is best to consult with special sources). We note only a couple of general patterns. So, for engraving on relatively soft and pliable materials (wood, glass, soft metals), high speed is not required, but for hard and difficult to process (steel, precious stones), a high-speed tool is better suited. But when drilling, note that for the same power consumption (see above), more revolutions, usually, means lower torque values. That is, here “high-speed” tools are better suited just for soft materials, and low-speed tools are better suited for hard and heavy materials.

The diameter of the collet provided in the design of the rotary engraver (see "Device").

A collet is a specific type of fastening: a split sleeve, the “petals” of which can be compressed and unclenched by twisting / unscrewing the clamp. For a number of technical reasons, this mount is considered optimal for engravers. In order to properly install the working nozzle in such a tool, it is necessary that it fits the diameter of the collet (to be more precise, the mounting size of the nozzle should not exceed this diameter).

Note that there are several standard collet sizes. The most popular is 3.2 mm, but there are other options. And some engravers can be equipped with several mounts of different sizes.

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).

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 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).

An indicator that signals the battery level in the corresponding tool (see "Power supply").

The device and capabilities of such a pointer can be different - from an LED "light" that gives the simplest signals by changing colour and / or blinking frequency, to detailed data on the instrument's own display. However, anyway, the charge level indicator makes it easier to monitor the state of the battery and reduces the likelihood of being with an “empty” battery at the wrong time.

A device for charging the batteries used in the tool with the appropriate power supply. For models supplied with such a device, the charger model may be additionally specified in the characteristics. This information can be useful not only for finding a spare or replacement charger, but also in case the household has other cordless tools and / or batteries for them. The fact is that many manufacturers nowadays use universal batteries that are compatible with a whole set of tools from the same brand; so, for example, a complete charger may be quite suitable for a cordless grinder or drill from the same manufacturer.
On the other hand, a lot of modern cordless tools come without a charger at all. This option will be optimal, first of all, if a compatible memory is already available, and there is simply no need to overpay for a second device. In addition, the lack of a charger will be appreciated by those who want to choose this accessory separately, without relying on the manufacturer's decision.

The presence of a case or cover in the tool kit.

A case is a hard container, a cover is a soft one; the main differences between them are due to this difference in materials. However, the purpose of both devices is the same: they provide ease of storage and transportation. This convenience is provided both by additional protection (in the case of covers — from dirt, in the case of cases — also from hits and shocks), and by the fact that all attachments and additional accessories, usually, are placed inside the cover/case, thereby reducing the risk of losing any of these items.

The noise level produced by the tool during operation. For comparison, 50 decibels roughly corresponds to the noise in an office room, 60 dB to an average TV volume, 70 dB to a truck at a distance of about 8 m, 80 dB to traffic noise, 90 dB to a loud scream.

The lower the noise level, the more comfortable the use of the tool. At the same time, note that this parameter is usually indicated very approximately — the actual “loudness” of operation can vary markedly depending on the mode, the nozzle used, the material being processed, etc.