Circle Projection on Tumbler

This article provides an excel spreadsheet to be used to calculate the skew needed to adjust a circle onto a Rotary Surface.

Prior to using this sheet, make sure your steps/roller diameter are correct for the cup you are lasering onto.

Rotary Roller Diameter Calculation

How to Use

Enter the values in the blue rows:

• Circle Diameter – Get that value from your artwork in Lightburn
• Cup Diameter – Measure the diameter of the cup where you are engraving

• Green Rows: FYI only
• Orange Row: Output skew percent — enter this into LightBurn.

In LightBurn

Unlock the X and Y Axis sizing and then enter the skew value for the X axis, then rotate your art and set it up for the Rotary. In this example a 2.75" circle with the X axis skewed by 3% results in a 2.8325x2.75 oval.