[How deep are you cutting per pass? You'd probably have best results by dropping the tool about 8mm at a time, and feeding a lot faster. Wood tends to burn if you try to cut it too slowly; the tool is rubbing more than cutting. Look at the chips you're making - they should be rather coarse, not fine dust. To get a better finish, you might go with a rough cut to remove the bulk of the material followed up with a finish cut to smooth the edges. ]