Euroboor VAC.50S+, Руководство пользователя

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5. Working with drilling accessories
5.1 Annular cutters
Annular cutters only cut material at the periphery of the hole, rather than converting the entire hole
to shavings. As a result, the energy required to make a hole is lower than for a twist drill. When
drilling with an annular cutter, it is not necessary to drill a pilot hole.
WARNING:
Do not touch the cutter or the parts close to the cutter immediately after
operation, as they may be extremely hot and cause burns to the skin. Ensure nobody is in the
work area where the metal core (slug) is ejected.
Drilling conditions
The ease with which material can be drilled depends on several factors including tensile strength and
abrasion resistance. Whilst hardness and/or strength is the usual criterion, wide variations in
machinability can exist among material showing similar physical properties.
The drilling conditions are dependent on requirements for tool life and surface finish. These
conditions are further restricted by the rigidity of the tool and the workpiece, lubrication and
machine power available. The harder the material, the lower the cutting speed.
Some materials of low hardness contain abrasive substances leading to rapid cutting edge wear at
high speeds. Feed rates are governed by rigidity of set-up, volume of material to be removed, surface
finish and available machine power.
Drilling a hole
Now that you have read the information and safety recommendations above, you are ready to
actually start drilling. Follow these 12 steps for best drilling result:
1. Install the annular cutter:
- Place the pilot pin into the cutter;
- Align the flat faces on the cutter shank with the screws in the tool holder;
- Make sure the cutter shank is entered fully and correctly;
- Tighten the screws;
[image 5-1]
2. Precisely mark the center of the hole;