I'm sorry you think my posts are not relevant. Maybe I don't spend enough time on the forum, but I have never read any threads about lubricating any PC bearings, or any other polisher for that matter. But my new DA which cost 2.5 times my PC apparently has to be lubricated every 6 mos. or it will blow up.
I don't think this is going to be worth arguing, but I have a car which cost over 100 times as much as my Flex but only requires about 30 minutes of maintenance every 6 mos., just like my Flex (or, if it's your Flex, 30 minutes a month). I like PM just as much as the next guy, but in today's world it's just bad design to have to do a 30 minute repair on a hand tool every 6 months. Use a sealed bearing, a self lubricating bearing (like the bronze bushing you mentioned), or provide an external lube point for grease or oil.