The ring cutting method is used to form large diameter holes. A manual power tool, an annular nozzle on a drill are used for work.One type of core drill is a wood crown.
Scope of use, main characteristics
Crowns on wood are designed to cut through holes, most often used to provide a seat under the socket.With their help, using a nozzle with a certain spraying, they process a tree, chipboardplywoodconcrete, plastic, metal.
For many types of work, samples with a diameter of 68 mm are suitable.
Core drill bits up to 65 mm wide are equipped with a shank with a diameter of 19 mm. Larger samples with a 32 mm fastener. The number of gear segments on the ring depends on the size of the drill bit. On average, circular saws have from 2 to 16 teeth.
Ring drills are also used to form a clean cut with a smooth internal groove surface. After work, you do not need to refine the workpiece, remove burrs, since they do not form.Before sawing holes, there is no need to pre-center, drill the surface to be machined. As a result, the time of work is reduced, the quality increases. It is possible to drill holes without dust, noise. The castellated milling cutter provides comfortable work.
Design features
Regardless of which material the crown is intended for, it includes several essential elements. Consists of a cutting head, shank and guide drill with a pointed end. Also included is a hexagon, with which the drill is clamped in a chuck.
The cutting head is made in the form of a solid cylinder edge with sharp teeth or as a collapsible design with a round seating socket into which the cutting ring of the required diameter is inserted.
The ring after installation in the socket does not close, has the configuration of a cut cylinder. Usually they get a working tool with a set of cutters of various diameters and one shank.
Stacked rings allow you to make grooves of a certain size, change nozzles. Each castellated milling cutter has characteristic slots or holes: chips are ejected through them, and the wooden cork is removed. On large-diameter samples, technological holes are located on the top, on smaller models - on the side.
In the independent manufacture of the crown nozzle, a metal pipe of the required diameter is used.
Preparation for work
The technological hole on the cup has an irregular shape, which prevents the nozzle from turning in the socket. It is recommended to tighten the clamping nut tightly so that when drilling grooves in a tree with a high load, the ring crown does not loosen.
After the centering drill and cutting nozzle are tightly fixed in their seats, the cartridge is installed in a manual power tool, and drilling is started. The hole is cut strictly perpendicularly.
Before working on the drill set the speed. Each additional millimeter to the diameter of the groove increases the vibration of the tool. Therefore, you should choose drills with high power, a convenient handle.
For softwood, 300 rpm is enough; for hardwoods, it is better to set the drill or hammer control at 500 rpm. Sharpening of crowns is carried out in workshops or at home.
Models
Overview of some drills.
Bison
The Zubr company produces wood crowns with centering drills from high-tech tool steel. A centering drill provides increased rigidity when working with soft and hard wood. Crowns are installed on a regular household drill, suitable for working with wood, plastic, plywood, chipboard, MDF, drywall.
Dewalt
Crowns are used to form grooves, holes when performing wiring, laying communication lines. Bimetal products do not blunt for a long time, even when in contact with nails, fittings, they are hardy.
Bosch
Crowns are hardy, do not overheat, do not deform during sawing, withstand a large number of drilling cycles without re-sharpening.
The table shows the sizes, prices for crowns of various types.
Model | Diameter mm | Drilling depth mm | A type | Price, rub |
Dewalt Dt8118 | 160 | 38 | Bimetallic | 630 |
Bison "Expert" | 152 | 38 | Bimetallic | 1031 |
Encore 19157 (set) | 67, 73, 83 | 25 | Tool steel | 272 |
Bosch (set) | 25 – 63 | 18 | Tool steel | 623 |