I printed two of the CS2 knives to glue together, and used a 100 link chain. i scaled the knives to fit my printer (flashforge finder) but in the stl they're as large as the original. To connect the knife and the chain i used a keychain ring. but melting them together works also (maybe). i've put the link so that u could make a longer chain/bigger knives. 

this is one of my first prints so i might make some flaws (sorry if thst happens) and i hope u like it!