"Battlebot" Repair (TIG weld 4130 Cr-Mo steel)

[jakeru]

Here is another job I did at the Northwest Model Hobby Expo

At the expo they had a raised, enclosed steel and bulletproof plexiglass "arena" where robots would "battle" one another with things like large rotating lawnmower blades spinning at very high RPM. I can't imagine how dangerous it would be to be near one of those robots without the steel and bulletproof plexiglass between you and it!

Anyhow, I got to repair a damaged "spinner" type battle bot for a competitor, so he could get back in the competition. Time was very limited, I recall I did the repair in 8 minutes start to finish.

The big gash in the robot body was caused apparently by another "spinner" robot blade slicing into it. The material of this robot was heat treated Chrome-moly steel. Something like 4140 or 4340 I think. I used TIG with 70S6 steel filler rod for the repair. This robot was in the 14 pound weight class, and it was a "spinner" type as well. (the robot body spins at a very high speed with blade extended around the outside.) The heat treating gave it a neat dark color all over it. I had to weld with little heat input to avoid damaging the sensitive electronics mounted on the opposite side of the metal. Apologies for blurry pics, that's what can happen when in a hurry I guess.

There is a *lot* of effort that goes into designing and making these custom robots, so I was kind of honored to get to weld on one.

PS - A little battlebot trivia: I heard the two Mythbusters guys met each other by doing battlebots.