THE MATERIALS
The main equipments for drilling are :
- manual traditional tools for the machining of wood in particular,
- drilling machine working on the sector,
- electric tools for which energy is supplied by a battery.
BRACE
It is the tool of the craftsman of former days. It still has its reason for being every time we wish to make drillings in a not too hard wood, and every time the number of holes is restricted. It is precise and cheap.
On the manual brace, we use conical-shank drills bits. Completely recommended for precision drillings, in particular big diameter, or still for drilling of blind holes.
THE DRILLING MACHINE
There are several types of machines: with or without percussion, taking their energy on the sector or those using the electric current supplied by a battery in the cadmium-nickel. Machines without percussion, allow to drill wood, plaster, metals, chipboards...
Machines with declutching percussion, allow the work in hard stones and the concrete. They are equipped with a system of high-frequency hammering called "percuteur", which works a little in the style of a hammer and contributes to disintegrate the concrete, or the granite. On a machine, the percussion can be engaged or not according to the material to be drilled.
THE SCREWING AND UNSCREWING MACHINE
This machine of recent invention works mostly on rechargeable battery. Its chuck is conceived to receive the various forms of screwdriver.
The used tip has to be polygonal and not cylindrical as for a bit.
This machine is used and justifies itself especially for one series production.
THE DRILLING AND SCREWING MACHINE
This machine as the previous one, works on battery. Besides the functions of screwing and unscrewing, it also authorizes the drilling in current little hard materials: wood,chipboard, metals, crowbars, at the most steel soft.
The advantage of this equipment with battery is that they eliminate the slavery of the thread; on the other hand they have a power sharply lesser than that of the machines working on the sector.
In this type of tool, who are a little bit expensive, the battery enters mostly on an autonomy of half an hour, where from the necessity, often, to have a second battery.
THE PERFORATING HAMMER
It is a kind of very big drilling machine, in which we would have replaced the percussion mechanism in by a system with connecting rod and valve insuring a higher return. The perforating hammers are essentially intended for the civil engineering works; they can work either on the sector, or on the battery.
With a hammer drilling machine, it remains necessary to exercise a pressure on the machine (for example of the order of 15 kg for the concrete), with the perforating hammer, this effort is divided by 3. Due to its performances it can also be used in hard wood.
THE INDISPENSABLE PERFECTIONS
The contemporary drills are multispeeds; they so allow to adapt themselves to all the cases of drilling, in application of two principles:
- The more the diameter of the hole to be drilled increases, the more the speed of cutting has to decrease.
- Also, the more the material is hard, the more the speed has to come down
- For every category of material, there is a range of optimal working speeds.
ATTENTION: quality of drilling and speed depends on the quality of the drill bits . An excellent drill working with inferior drill bits never gives good results.
THE ACCESSORIES OF DRILLING
Their function is to simplify the work of the user, either by releasing him a hand, or by improving the precision of the guide.
The column of drilling :
It receives the drill on its support and allows tangent, secant drillings, reamings, without that the bit breaks itself; ideal also for the drillings of mass holes support, the only defect of which is to be a little bit cumbersome.
This equipment allows to make precise holes in assembled parts or isolated of small or strong thickness.
The vice of centring :
It is the complement to column of drilling.
He allows to block the part during the work, so releasing one of the hands of the user.
