WoodWorkCalc
CNC · Workshop tools

CNC Ball-Nose Scallop Height Calculator

Compare theoretical cusp height from ball-nose diameter and stepover on a flat surface.

Set up your calculation

An illustrative example is loaded. Replace its values with your measurements, costs or documented settings.

Tooling help: Ball-nose geometry

How this works

Calculation

Your result

Theoretical scallop height
0.015038 mm
Scallop height
15.038 µm
Stepover percentage
10 %

The quote handoff carries your inputs and assumptions. Only an explicit base cost is suggested as a quote cost; prices, rates and measurements remain planning notes.

Choose the tool and check the setup

Understand the cutting profile, material reference and equipment limits before applying the result.

Understand the result

Method & assumptions

For radius R and stepover s, cusp height = R − sqrt(R² − (s/2)²). A numerically stable equivalent is (s/2)² ÷ (R + sqrt(R² − (s/2)²)).

  • Ideal spherical tip, parallel passes and a flat surface with no tool tilt. Sloped surfaces require a different effective cutting geometry.
  • The result is geometric cusp height, not measured roughness or a safe feed recommendation. Runout, grain, tool deflection and sanding change the finish.
Worked example

Work through the cnc ball nose scallop example

Work through the cnc ball nose scallop example
Input or stepExample value
Example inputs6 mm ball-nose cutter and 0.6 mm stepover
Theoretical scallop height0.015038 mm
Stepover percentage10 %

These values match Load example. They illustrate the method, not recommended material, machine or pricing settings. Read the assumptions before using the result.

Common questions

Are the example settings a recommendation?

No. Replace the example with measured dimensions, actual costs and your product or machine manufacturer's limits.

What if an input is incomplete or impossible?

The result is hidden and a field or calculation error explains what needs correction.

Use this in your project

Continue with the next measurement or cost, then keep the assumptions with your quote.

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