Processing wood with power tools it is not only much easier than manual processing, but it allows you to achieve effects that were previously completely unattainable. All over the world, there are many different companies specializing in the production of these devices. Some of them produce devices equipped with their own propulsion, others – simple devices, for the drive of which a drill is used, often multi-speed or with internal electronics, enabling precise and stepless adjustment of the spindle speed from zero to several thousand revolutions. The rotational speed of the drive motors of drills manufactured by the world's leading companies is up to 25 000 obr./min., with powers often reaching 1 kW.
For us, the most useful is the domestic Celma PRCrlO / 6IIB drill and various attachments powered by this drill, such as chainsaws, grinders, impact sockets etc..
The drill shown in the picture, powered by mains voltage 220 V, is equipped with a powerful drive motor 350 W. Drill housing (1) it is made of high-impact plastic. There is a drill chuck at the bottom of the housing (2), from which the switch button protrudes (7) and switch lockout button (8). In the front part of the housing there is a two-speed gear transmission (3). Narrowing of the housing (4) it is used to connect the drill with attachments constituting its additional equipment. The rear part of the housing (5) houses brush holders and the rear motor bearing. After removing it, you can check the condition of the commutator and the wear of the brushes, which is extremely important for the operation of the electric motor.
The drill bits are clamped in a three-jaw chuck (6) screwed onto the threaded end of the axle equipped with a bead ground on both sides (10). When installing the handle or sleeve connecting the drill with attachments, a flat key is inserted on the grinding of the thickened axis, included in the factory accessories of the drill.
And one more, a very important element – drill speed switch (9). In the front of the case (3) there is a two-speed gear transmission. When shifting the transmission to 1 without load, the drill spindle rotates at a speed of approx 1000 obr./min., while on 2 running at a speed of approx 3300 obr./min. We usually drill holes in wood with twist drills, the same, how to drill holes in metal. The condition of the drills is very important here, which should be smooth and sharp. Let's remember, that for drilling holes up to approx 6 mm, the drill must be set to 2 run, while the holes have a larger diameter, do 10 mm, fidgeting on 1 running.
We drill holes in thick elements in stages, to prevent the drill bit from jamming in the wood. After each 5 mm of the drilled hole, pull the drill up, which removes the chips, then we continue drilling. We proceed in a similar way when drilling holes in thinner elements, made of moist or resinous wood.
In a home workshop, it is worth having a set of drills with diameters from 1 do 10 mm, co 0,5 mm. The set includes approx 20 drills, which should not be kept together in a box, stacked on top of each other, because they dull very quickly this way. Therefore, we recommend that you make a drill stand yourself in the form of a wooden block of thickness 40-60 mm, with dimensions of approximately 60×120 mm. We drill holes in two or three rows in the block – one hole with each drill, that each of them has its own appropriate, carefully marked place.
Let's remember, that the drill is an essential power tool, because it is also a power source for other attachments.