Cutter head radius

The cutter radius r_c0 is the nominal radius of the face type cutter or cup-shaped grinding wheel that is used to cut or grind the spiral bevel teeth. The cutter radius determines the curvature in the lengthwise direction of the tooth.

There are different standard face cutters for the different manufacturing processes (face hobbing, face milling). For the face hobbing method, the gradation of the cutter head radii is additionally dependent on the number of blade groups z₀. Different cutter radii are also optimal for different manufacturing processes. The ratio of cutter radius to the mean cone distance of the wheel is usually taken as the criterion for this (small-cutter and large-cutter design).

The cutter radius r_c0 can be specified or a standard cutter radius (see Table E.1 in ISO 23509:2016) is determined automatically depending on the gear cutting method, the mean reference cone distance R_m2 of the tooth depth form and cutter head properties. The following selection is available, whereby in some cases the associated number of blade groups z₀ is also set automatically:

• User specification of the cutter radius r_c0
• Single-indexing, tapered tooth depth: Calculation of the mean reference cone distance R_m2, selection of a cutter head for "face milling" with  r_c0 ≈ R_m2, number of blade groups z₀ = 0,
• Single-indexing, constant tooth depth: Calculation of the mean reference cone distance R_m2, selection of a cutter head for "face milling" with  r_c0 ≈ 0,8 * R_m2, number of blade groups z₀ = 0,
• Continous indexing, two part cutter (two divided cutter parts for inner and outer blades): Calculation of the mean reference cone distance R_m2, selection of a cutter head for "face hobbing" with r_c0 ≈ 0,6 * R_m2, (e.g. Cyclo-Palloid), and selection of an associated number of blade groups z₀,
• Continous indexing, two part cutter: Calculation of the mean reference cone distance R_m2, selection of a cutter head for "face hobbing" with r_c0 ≈ 0,8 * R_m2 and selection of an associated number of blade groups z₀,
• Continous indexing, three part cutter: Calculation of the mean reference cone distance R_m2, selection of a cutter head for "face hobbing" with r_c0 ≈ 0,8 * R_m2 and selection of an associated number of blade groups z₀,
• Toothing with quasi-straight tooth trace curve: rc0 = 800 mm, approximately straight toothing due to the large tool radius.