Eccentric Turning Calculator

| Added in Construction

Formula

The eccentric turning process formula is:

$$\text{ETP} = 1.5 \times \text{Offset} \times \left(1 - \left(0.125 \times \frac{\text{Offset}}{\text{Bar Diameter}}\right)\right)$$

Where:

  • ETP = Eccentric Turning Process value
  • Offset = Offset distance from center
  • Bar Diameter = Diameter of the bar being turned

Example Calculation

Given:

  • Offset: 2 inches
  • Bar Diameter: 5 inches

Calculate:

$$\text{ETP} = 1.5 \times 2 \times \left(1 - \left(0.125 \times \frac{2}{5}\right)\right)$$

$$\text{ETP} = 3 \times (1 - 0.05) = 3 \times 0.95 = 2.85 \text{ in}$$

This calculator helps machinists determine the eccentric turning process value for lathe work, which is critical for achieving proper offset in turned parts.

Frequently Asked Questions

Eccentric turning is a lathe operation where the workpiece is mounted off-center to create parts with offset features like camshafts, crankshafts, or decorative turned pieces.

The ETP is calculated using the formula: ETP = 1.5 x Offset x (1 - (0.125 x Offset / Bar Diameter)). This accounts for the relationship between offset distance and workpiece diameter.

The bar diameter affects the amount of material available for turning and limits the maximum possible offset. Larger diameters allow for greater eccentricity while maintaining structural integrity.

Eccentric turning is used to manufacture camshafts, crankshafts, eccentric shafts for pumps, decorative woodturning, and any component requiring off-center cylindrical features.