Buy 3/4" PVC pipe. Cut to length. Print 1 pommel, 1 body, 1 choke and 1 emitter. put epoxy in the pommel and insert PVC. Put thin coat of epoxy on pipe and slide on body, then choke, then emitter.
Don't smack around too hard. PVC shatters if hit too hard. This is for very light sparring only.
Print and use at your own risk. I take no responsibility if you break something, hurt someone or hurt yourself. Have fun.