This year my high school entered a battlebot into Battlebots IQ and we got 6 out of over 60 battlebots but I’m not here to brag. We had a full body spinner made out of Grade 5 (Military Grade) Titanium and 4 interchangeable Hardened S7 Tool steel Teeth each attached to the shell with 6 l9 bolts made of AISI 8640H the shell was around 4-6 inches tall (can't remember and it is the weekend right now so I don’t have the plans in front of me) It's shell is shaped simply like a hollow cylinder with no bottom. The Tip Speed of the teeth was about 343mph. during our 4 battle one of our teeth mounts broke off at the weld. We welded back that night and the next day during the 5th fight the other side’s tooth weld broke. Also a chunk of the titanium actually came out of the backend of the weld. Also their spinning s7 blade took a chunk out of the top of the side plate. See the attached picture that I threw together in paint real fast to get a visual of its makeup. (not to scale) My question is this. What kind of harder materials or different mounting methods could we use next year that could prevent mounts from breaking off (also our teeth’s tip speed will be reaching 400 mph next year)? Also is there some way or different material we could use to prevent s7 from being able to pierce our shell? also is their a good website I can go to to learn more about metalurgy and structural integrity?