Brush Arrow Rest, added to the bearings will eliminate the dust from entering the bearings, thanks for the video, I will be adding some of your idea's to my build. I've been researching for the flattening sled, to get the best sled possible, there are so many builds going on with lots and lots of idea's. thanks for what you do.
You should replace those linear bearings with bushings instead (McMaster calls them 'sleeve bearings'). They'll be much more tolerant of dust and debris, and they're cheaper too!