VEX Pro Ball Shifter Ratios

[Adrian Clark]

This year we are using a custom 3rd stage on the new VEX Pro ball shifter gearbox so that we can tweak our ratios with much more flexibility. Due to nature of this years game we might need to cross the whole field to get to the feeder station, so we wanted a gear ratio that put us around 16-17fps. Because of the low spread on the ball shifters we found that if we geared to 16-17fps in high gear we didn't have enough pushing force in low gear.

On the VEX website in the ball shifter description they state that they choose the 2.27 spread because it was better suited to a FRC robot than other off the shelf gearboxes. Unfortunately it seems that for our desired use that is not the case and a 2.56 or 2.66 spread from an AM shifter or custom gearbox is much more useful than a 2.27 spread.

For everyone using the new ball shifters: what speeds are you running? have you had to compromise your top speed for pushing power or is the 2.27 spread just right for you?


As a disclaimer, i'm not trying to bash on ball shifters. I think there great for teams that want to go 13-14fps max, but unfortunately that's not us.