On each Planetary Gearbox Specification Sheet, on the upper half of the page in the 1-stage, 2-stage, and 3-stage columns, is a vertical listing of available Gear Ratios.

Next to this listing of Gear Ratios is a listing of Motor Shaft Diameters, in units of millimeters. This is the maximum available Bore Size for the Pinion for that particular Gear Ratio. In other words, the Motor Shaft upon which the Pinion Gear is to be mounted can be that size or smaller.

For larger Motor Shaft Diameters an Optional Pinion Adapter is available as pictured above. This is a Flexible Coupling with one end custom sized to fit ANY Motor Shaft. The other end has a Pinion Gear that precisely fits the Gearbox.

Surrounding the Coupling is a Spacer-Adapter that is machined to match both the Motor and Gearbox.

Additional information on how the Gearbox is mounted to the Drive Motor is provided on previous page titled "Planetary Gear Mounting".