round ends on a square slat

How many slats will need to be rounded?
If it is only one or two, you could do it by hand with a chisel. Many? Build a jig that will hold the slat above the router bit. Rotate the slat above the bit. It’ll be scary, but will work.
Bill

-- bill@magraphics.us

There are tennoning bits for a handbrace that do this kind of work…

-- We must guard our enthusiasm as we would our life - James Krenov

If it is for a short length, It is pretty fast to do with hand tools. You can use a spokeshave and start by drawing an octagon to approximate your circle. Take the edges down with the spokeshave, then take the new smaller edges, etc.. until you get a round.

-- Yves

Wayne,

I am not familiar with that accessory. What is it called exactly and are those easily found on ebay for example?

-- Yves