The sweep mesher expects at least two side faces. You can split the body in DM by a plane so that there are two side faces. You have another choice of using the multizone method. You can think of this as a more intelligent sweep, and it is intended to eventually replace the sweep mesher, but right now we have both of them. The multizone method will mesh this without needing to slice geometry. The multizone will work if src/trg selection is set to automatic, but it won’t use the “sweep size behavior” and “sweep element size.” So if you set it to “manual source,” you can specify the “sweep element size” to control the number of sweep divisions.