I am new this year on FIRST, and i was wondering if ball bearings will begin to “lock up” after long periods of use
That is one of the nice things about FIRST. Unless you are able to get considerable drive time before the ship date, you do not usually have to worry about Ball Bearings. Think of it this way, 24 hours of running your robot equals about 640 matches, with very little continuous use. We have never had problems with ball bearings on our robot. I guess it depends on what you consider long periods of use.
EDIT: Making certain that they are lined up to begin with also helps.
I’ve never ever seen a ball bearing lock up in FIRST. 330’s practice robot last year went through the mill–the drivers barely waited for the batteries to charge before driving again; it won a preseason, and is still running today. No bearing failure.
Ball bearings usually are overkill for a FIRST application and should last far beyond the life expectancy of your robot.
A couple of things to note: Ball bearings like even loads meaning that the shaft that goes through the bearing pack (I’m assuming you are using a bearing pack and not just ball bearings in a channel) is in line with the hole and not canted. The other thing is that ball bearing packs tend to not like side loads.