Gotcha thanks for the reference. Cool effect, I would use a CNC to get the same effect personally, doing it by hand is going to take a bit of effort, but the grinding wheel you were looking at may work for ya. I have a colleague that hand carves all of his work (similar to yours but he mostly makes bowls and spoons for trade shows) He uses nothing but chisels and knives and a wood lathe. I would figure out a way to ensure you do not go too deep in the grooves and keep it consistent, otherwise this will be a good practice. To make it easier, after gluing up the 2x4s I recommend planing the new board down flat so you won't have the grooves to deal with.