Vari-Roll Distance Calculator

How to set a Vari-Roll distance for gear measurement

A Vari-Roll, and most gear checkers in general, rely on the precise spacing between a test gear and a master gear to measure differencs and deviations between the pair. However, your test gear and master gear will often run on differently sized shafts, and may not have a specified center distance.

How can this calculator help?

This calculator requires the two shaft sizes and then either a test center distance, or the geometry of the gear pair, to provide the measurable spacing between the shafts. Finally, if the output spacing is between 0.3" and 8.0", the calculator will provide a gauge block stackup based on commonly available sizes.

Units mm (Module) 1/inch (Diametral Pitch)

Shaft Size (Gear 1)*

Shaft Size (Gear 2)*

Enter fixed center distance:

Center Distance

Or calculate center distance from gear geometry:

Number of Teeth (Gear 1)

Number of Teeth (Gear 2)

Or calculate a combination:

Master Gear Test Diameter

Number of Teeth (Gear)

Number of Decimal Places

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Here's a Quick Summary:

› Input shaft sizes

› Add center distance or gear geometry

› Output spacing for gauge blocks