How to choose woodworking cutters?--part2

Selection of woodworking cutters

1. identify the main technical parameters of the cutter
   Main parameters:outer diameter, machining thickness, and the center diameter.
   Other technical parameters: number of teeth, the direction of rotation, rotation speed, feed rate, clamping way, and cutter material.
2. Choose the structure type of cutter
   According the request and characteristics of cutting object, and consideration from both the technical and economic aspects, select the whole cutters or welding cutters, assembly cutters, and combination cutter.
3. The choice of the cutter rotation direction
   Cutter rotation direction is determined in accordance with the direction of rotation of the processing machinery spindle and the tool axis and the feed of the work piece relative position of the whole cutter, or assembling cutter, the inclination of the cutting blade relative to cutter radius determines the rotation of the cutter direction.
4. Selection of cutting amount of end mills
   Cutting amount of end mills are including cutting speed, feed speed of work material, and depth of milling. Cutting speed depends on the rpm and the radius of the end mills .. feed rate depends on the requirements of cutting surface .. the surface roughness of work material largely depends on the feed rate per tooth during cutting process, too much feed will cause too rough surface of work piece; too small feed will cause burnt phenomenon on the surface, so the feed rate must be appropriate.
5. Operation stability of end mills
   The stability of the cutter operation is to ensure that the basis of the machining accuracy and surface quality .. including two aspects: one is cutter excited vibration in machining due to external forces; the other is that cutter happens deformation by external forces.
6. Safety of milling process
   The safety of the milling cutter includes the limitation of rotation speed, the limitation of chip thickness, height restrictions of molding cutter contour and the thickness of assembly cutter, and stretched limit.
   Cutting timber is characterized by high speed cutting, the rotation speed of the milling cutters mostly above 3000 rpm. High speed cutting for timber brings high productivity and smooth surface .., it also brings a series of security problems. Therefore, when the spindle speed up to 9000 rpm, besides the cutter which diameter smaller than 16mm, it should prohibit to use assembly cutters and do strict testing and inspection for welding cutter.
   It is necessary to limit chip thickness for avoiding overload of cutters. For end mills, the clamping method, cutter height, and thickness of work piece are with close relationship. When you ensure the thickness of work piece, mill diameter, and center diameter, the height of cutter reflects its own strength, stiffness, and capacity of cutting resistance. The height must be limited to ensure the safety of cutter usage.
   The design point of welding end mills is clamping problem. No matter the body is cylindrical or disc-type, the blade clamp form must be guaranteed to provide sufficient clamping force to resist rotation centrifugal force .

Reference sources – China Timber Net