Pretty entertaining to watch. The author build this planer where its on wheels (casters) instead of a slide and stationary device I have seen in the base for home built planers. Clever build overall. My 2 cents, if he wants to get rid of the jiggle from the casters turning, you could use ball point casters.
Also this could be a good jig to use to engrave into wood as well.
http://www.instructables.com/id/Adjustable-DIY-Router-Planer-Mobile-Jig/