Making cylinders on a table saw

If he can't do it by regular turning on the lathe, I think he'd be safer making a jig for his router and doing it on the lathe. Lots of people use routers on the lathe for fluting and other embellishments.
I don't know how likely it would be to happen, but if a tooth caught in the workpiece that arrangement would be on the other side of the shop in an instant.

@Bill Howatt, several commented on that post saying it all seemed rather sketchy. It made me nervous just watching it.

I’ve done something similar to make a tenon and chamfered shoulder on some rustic stair spindles in a log home.  They came pre-made, but only at a length appropriate for a horizontal handrail.  For the spindles on the stairway, I had to cut them down, then cut the tenons and shoulders somehow.  I didn’t have the money for a large tenon/shoulder cutter, so I made a jig and did it on my tablesaw.  I used a lag screw through one end of the jig into the spindle, and then one into the spindle on the other end so that I could chuck it in a drill and spin it.  I don’t recall if I raised the blade as I went, or had the jig hinged so that I could slowly lower it onto the blade.  Either way, it worked great.

Jason

Doing the outside of the cylinder is one thing, but boring the inside accurately for the shown piston-fit is another.  Since it shows segmentation, you've gotta have very careful glue-up on the rings with the inside curves on each segment very carefully  matched.
Don't think I'd like trying to mount and bore out the inside.  Need great faith in your glue joints as the opportunity for shrapnel would be "special."