Comparison Jet JDP-13FM vs Jet JWDP-12

The number of spindle speeds provided in the design of the machine.

The more speeds(with the same difference between the minimum and maximum number of revolutions, see below) — the more options the operator has to choose the operating mode and the more accurately the machine can be adjusted to the specifics of a particular task. However the specific values of fixed speeds, even for similar models, may be different; but most of the time the difference is not significant. In addition, multi-speed machines can be supplemented with smooth speed control (see "Functions"), which allows you to fine-tune the operating mode even more precisely.

Note that switching speeds can be done in different ways: in some models this is done literally at the touch of a button, in others you need to delve into the gearbox or belt drive.

The lowest spindle speed provided by the drilling machine.

Note that this parameter is indicated only for models with more than one speed (see "Number of speeds") and/or speed control (see "Functions") — that is, if the speed can be changed one way or another. See “Maximum number of revolutions"; here we note that the ability to work at low speeds in some cases is critical — for example, when threading. Accordingly, the lower the minimum speed, the better the machine is suitable for such work, other things being equal. The most "slow" modern models are able to rotate at a speed of 30 – 40 rpm.

The highest spindle speedprovided by a drilling machine; for models with only one speed, it is also indicated in this paragraph.

For the same engine power (see above), high RPM provides good performance, but torque is reduced; at lower speeds, on the contrary, the pulling force is increased, allowing you to “bite” into stubborn materials and make it easier to work with large diameter drills. Specific recommendations for optimal speeds depending on the type of material and drilling diameter can be found in special sources. At the same time, we note that a high-speed machine will not necessarily be “weak” in terms of torque — after all, many units allow you to reduce the rotation speed. However, efficient operation at high speeds still requires a fairly powerful engine, which accordingly affects the cost of the unit. Accordingly, it makes sense to look for a “fast” machine if you plan to work a lot with relatively soft materials, such as wood. But for metal, stone, etc. it is better to choose a relatively "slow" unit.

The largest spindle overhang provided in the design of the machine.

The overhang is the distance from the centre of the spindle to the supporting column. The maximum overhang corresponds to the greatest distance from the edge of the workpiece to the centre of the planned hole, at which this hole can be drilled on this machine; if this distance is greater than the overhang, the workpiece will rest against the support column and the drill simply will not reach the right place.

Note that this parameter is relevant only for vertical and radial machines (moreover, in the first case, the overhang is generally unchanged; see "Type"). But magnetic models do not have a limit on the size of the workpiece, so the overhang is not indicated for them at all.

The diameter of the support column used in the machine. In fact, it is a purely reference indicator that does not play a special role in the normal use of the unit; data on the diameter of the column may be needed only for specific tasks such as repair and maintenance.

Dimensions of the base plate installed in the machine.

The base plate is the surface on which the workpiece is placed during operation. Accordingly, the larger this surface, the better this model is suitable for working with large parts (especially since the dimensions of the vise for the workpiece installed in many models depend on the size of the plate). However, usually manufacturers choose a base plate, focus on the overall level of the unit and approximately assuming the largest size of the workpiece with which it will be used. And magnetic machines are not equipped with a base plate at all (for more details, see "Type").

Note that for base plates, dimensions are usually indicated by the greatest length and width, and regardless of the shape. This means that, for example, a plate measuring 300x300 mm can be not only square, but also round.

The dimensions of the base of the machine — the platform, thanks to which it is able to stand steadily on the floor or workbench. This indicator allows you to estimate how much free space is needed to accommodate the unit. More powerful, larger and, accordingly, heavier machines have a larger base diameter.

The type of chuck — a clamp for installing drills and other working nozzles — used in the machine.

— Key. Chuck opened and closed with a special key. Also known as "gear" or "ring gear" because the wrench works like a gear. It is used to secure drills with a cylindrical shank; for this, the design has cams (usually three) that converge when closing and diverging to remove the drill. The cam clamp itself is quite versatile and is able to work with any drill or other attachment that has a round shank (regardless of its additional features). For example, even nozzles with a Weldon shank are sometimes put in such a cartridge (see below). Specifically, the key cartridge is considered somewhat more reliable than the quick-clamping one similar in principle; its main drawback lies directly in the use of the key, which can be lost. In addition, the replacement itself takes a lot of time.

— Quick release. A chuck for cylindrical shanks, the design of the clamp is completely similar to the key (see above). The main difference is that the keyless chuck is opened and closed by hand, without the use of any special tools. Due to this, changing drills takes much less time (hence the name), and in general, working with such a cartridge is easier than with a key one. It is considered the best choice for those cases where you need to change drills frequently. The disadvan...tage of keyless chucks is considered by some to be less reliable than key chucks; however, this may turn out to be critical only at very high loads, and for normal use, the capabilities of such a fastening are quite enough.

— Morse taper. Morse taper is a specific type of shank used in drills and other similar bits. Such a shank, in accordance with the name, has a conical shape — the socket in the cartridge is designed for it. At the end of the shank, there is most often a foot — a flat ledge, which, when installed, is fixed in the groove of the cartridge and does not allow the drill to turn. However, there are other options for retainers — for example, with a thread, when a special rod is screwed into the end of the cone during installation. In order to select compatible drills, it is imperative to know the design features of a particular Morse taper chuck. Also note that such fasteners are available in several standard sizes (see "Morse Taper").

— Weldon. The Weldon clamping system features a cylindrical shank with a flat, a small flat notch on one side. The chuck has a clamping screw, which, when tightened, rests against the flat and fixes the drill in the socket. A rather exotic type of fastening, which has not received much distribution in the post-Soviet space. This is partly due to the fact that the Weldon drill can be clamped in a regular shank chuck without much difficulty (although this is not particularly recommended, as it can lead to imbalance at high speeds). This type of chuck is mainly used in magnetic machines (see "Type") — and then most often in combination with another, more common type of fastening (for example, quick-clamping).

— collet. A cartridge that uses the same working principle as an automatic pencil. The role of the clamp is played by a round sleeve, divided into several springy petals; in the working position, they are compressed and fix the drill, and to open it, you need to pull the chuck casing up, and the petals will disperse. This way of working is not reliable enough for full-size drilling machines, but it is optimally suited for high-precision units using small diameter drills (up to 4 – 5 mm).

Note that several chucks can be supplied with a drilling machine at once, including those for different types of shanks (for example, Morse taper and key). The latter significantly expands the range of working nozzles available for the unit. At the same time, a specific combination of fasteners can be practically any — except that the key and keyless chuck are not supplied in one set, because. they are designed for the same type of shanks.

— Reverse. The possibility of rotating the spindle in the opposite direction — to "unscrew" the drill from the material. The main function of this function is to free the tool stuck in the workpiece. In addition, reverse can be useful for some specific types of work, such as threading (in fact, almost all machines with reverse allow this use).

— Adjustment of frequency of rotation. In this case, the ability to smoothly change the speed of rotation of the spindle is implied. This allows you to fine-tune the speed much more precisely than by choosing one of the fixed speeds (see "Number of speeds"). In this case, both methods of adjustment can be provided in the same machine. Anyway, models with smooth adjustment are considered more advanced than units without it.

— Auto speed control. An automatic system that regulates the power supplied to the spindle depending on the load on the drill — in such a way that the rotation speed of the tool remains unchanged: at high loads, the power increases, at low loads it decreases. A constant rotation speed has a positive effect on both the quality of processing and the service life of the drills and the machine itself.

— Brushless motor. The brushless type electric motor does not have carbon brushes. Such units are much more complicated and more expensive than classic collector motors, but they have a number of important advantages over them. These are, in particular, high ef...ficiency, minimal heating during operation, durability, very low noise level, as well as an almost zero probability of sparks, which allows you to work safely in conditions of increased fire danger.

— Backlight. The presence in the machine of its own lighting system — in the form of a lamp aimed at the place of work. This function makes the unit independent of external lighting and allows you to work comfortably even in low light (up to complete darkness). And in the daytime, the light can be obscured by surrounding objects, or even by the machine itself; in this case, the backlight will also be useful.

— Laser marker. A laser marker that plays the role of a “target indicator”: a mark from it shows a point on the workpiece that the drill touches if it is lowered right now. This feature makes it much easier to point the tool at the desired point.

— Digital display. Own display, which can display various numbers and special characters. Usually this is a fairly simple screen for 3-4 digits, however, even such a screen is more informative than indicator lights. For example, the display can show the exact spindle speed; and in general, this function makes the management more convenient and intuitive.

— Coolant supply (coolant). A system that allows you to supply cutting fluid (coolant) to the place of work. This function is especially important in “heavy” work, with intensive processing of hard materials or delicate parts: by reducing heat and friction, coolant prevents deformation of workpieces, reduces the likelihood of defects and overall tool wear. In addition, the coolant can perform other special functions, such as anti-corrosion treatment. Note that the design of the supply system can be different — from the simplest tank above the spindle, from which coolant flows by gravity, to a separate pump with its own engine. This point before buying needs to be specified separately.