Lego EV3 Caster ball

thingiverse

Lego Education kits don't come with the caster and steel ball '2000702', which can be found in commercial ones but are often unavailable in many countries. For those who can't get their hands on this specific caster, there's a suitable alternative available. This particular caster is designed for use with marble or glass balls that have a diameter of 16.1mm. It's worth noting that the size of the ball can make a difference - if it's too small at 5/8 inch, it might not fit properly, while a 2/3 inch ball could be too tight. This caster is necessary for building the Robot Education rover unit from the commercial EV3 Mindstorm kit, model number 31313. However, keep in mind that the Lego Education version has larger wheels than its commercial counterpart, so the caster might not fit as snugly.