Ball differential

The first ball differential for Radio-controlled Cars was designed by Cecil Schumacher, a British motor sport engineer working at Cosworth and founder/owner of his eponymous model brand.

Radio-controlled cars were still a new application for the ball differential and Schumacher is generally considered the modern day inventor of the concept.

Such was the popularity of the ball differential, originally applied in 1/12 on-road cars, that he formed his eponymous company.

They are used on almost every 1/12 on-road, scale touring car (although the sealed gear differential is gaining popularity in this class) and electric off-road produced by many manufacturers.

The main part of the differential is a drive gear (or pulley in a belt transmission) with multiple holes cut through it, following its outside diameter.