What was you guys' strategy going into this fight with Gamma 9? Hit with a hammer? Hit em with the
hammer, yeah! I mean I've done some hydraulic projects before and you have to want to be covered
in hydraulic oil all the time, because that's going to happen. It wasn't until we had a chance to
breathe for a second. I was like "oh yeah, he hasn't moved in like... 20 seconds". A while,
yeah. And it works I mean it's a walking robot and it's a giant freaking hammer!
Today we're talking with BattleBots Co-creator Greg Munson and this season's only walker bot,
Chomp! On this episode of Behind The Battle! Chomp, Chomp, Chomp, Chomp, Chomp!
Hi everyone, I'm on with Zoe and Jascha, from Team Chomp! How's it going, guys?
Pretty well, nice to talk to you! How did you two get started in robotics? Yeah, I competed first
in BattleBots, Long Beach 1999. I was inspired by seeing Robot Wars, and I went and attended
it in person while I was in high school. Finally built a robot five years later and brought it to
Long Beach and it did terribly. But after that, I went with pneumatics, and I built The Judge
and I've kind of been sticking with the pneumatics theme since then, since they're so much fun.
And then when BattleBots was going to come back, I happened to work with a lot of
folks who had done BattleBots in the past. And so they were writing to everybody and they were
saying "we're going to, come back, we're going to come back, we're going to reboot!
Will you build a robot, because we know that you're a good builder. and for various reasons
a lot of the people around me my coworkers Jascha other other folks they said "well...
I can't right now" "not this year" Jascha was doing a different robotics competition.
"We're too tired". "We're too tired" like "we've got kids now, it's too expensive"
and I was kind of thinking I was pretty um early in my career in engineering and I thought like...
well I could try? What's the worst that can happen I'll probably learn a lot!
And so I wrote up a proposal for the first Chomp, which was this crusher.
And I sent it in and I said you don't know me, but I know all these people
like... you know? Maybe they can vouch for me and would you take me? And they said "yeah". How
did you kind of connect in the BattleBots like? Yeah so, we are married. It's true.
Rings and everything! We were dating at the time he was really involved in this other
robotics project, but he did say like I can help you out some on... you know just like figuring
out how to even do this. I had never built a robot before. So he's been a part of the team,
of the Chomp team since the beginning. I would say that this year especially with Chomps legs
those are really Jascha's baby, and he did a lot of it while I was... I'm currently very pregnant.
I'm eight months pregnant, um and in the first part of pregnancy often you're like really really
exhausted. So there was this period on the build of this current walking Chomp where really it was
just like Jascha plugging away on making walking Chomp work. We're here with Greg Munson the
creator of BattleBots with our special guest Grant Cox! So I was really excited to get the chance to
talk to you again this year because last year when we spoke, you spoke a lot about walking robots you
know the move towards anthropomorphism, you know kind of that being the next stage of BattleBots
and we got one this year! What did you think of Chomp this year? Yeah, we always knew Zoe and
Jascha and their team were working on something for a while they've been wanting to build this
big. Because all along BattleBots said where do we set the limit? Is it twice? We finally said "okay
it's twice" it's gonna be 500 lbs as long as it's a real walker. We actually had a meeting with Zoe,
Jascha, Peter Abrahamson, Luke our head of safety, Mark Setrakian was there,
Scott Lavalley, was there. All these like really toppings and your smart people were there we said
"okay let's make the rules for the walkers". And everyone agreed just make it simple, and then
people can submit designs, and then we'll say "that's a walker" or "no, that's not a walker".
How did the legs transpire? We've talked with Greg about the idea of making legs for a long time and
you know back in the day Mark Setrakian did make some legged robots. And they were beautiful,
but they faced all the problems that you would expect with legs, like the level of complexity is
so much higher than wheels, like you can you can make a robot with two motors and two wheels and it
drives great, done. And a six-legged robot-like Chomp or like Mechadon you're almost certainly
looking at you know, three degrees of freedom per leg. So now you're looking at 18 actuators,
and they're not just motors they're you know they're they're position-controlled actuators.
Just the cost and complexity goes through the roof and so to make it even somewhat viable you know
we were arguing for a 100 weight bonus you know? Let the robot weigh twice as much as other robots
and there was some hemming and hawing about that. "Maybe we'll just let it weigh 50
more?" and I felt... We'll give the 50 lb bonus it's like...
We both felt pretty confident that a 100% would make it maybe just make it viable. And after
actually building one, I absolutely stick by that. Even as even as Chomp ended up,
she was still not as armored as we'd like. And it was just a nightmare making her make 500 lbs.
It's like you could make a 200 lb base and then what? Are you gonna have a 200 a 300 lb
spinner? No, no you can't do that's like gonna kill the arena. So we limited not only we maximize
the walking limit to 500, but we minimized the weight of any spinning weapon to 80 lbs,
and then sort of grandfathered in the full body spinners like Captain Shrederator at
120 and Gigabyte. And all this was was sort of predicated upon for years obviously we wanted
to do a walking class. Mark Setrakian has been teasing building something, but it was really
Zoe was sort of the catalyst of getting these rules out there, because she wanted desperately
to update Chomp and make it a walker. And so we got the rules out and instantly her and Jascha are
going to town. I mean even on that rule meeting they were already building. And they were doing
stuff with pneumatics to get the legs to walk with these fast acting valves that could really make
the thing nimble and quick that were amazing, like they wheeled it in like on the last day you could
possibly safety inspect it and they're still tweaking. And then they have this fight against
Gamma 9 and it works! I mean it's a walking robot, and it's a giant freaking hammer! There are some
hard decisions with legs as soon as you start talking about legs you're talking about something
that's far more fragile than a wheel. You just as an engineer you have horrible nightmares of like
gearboxes inside of your legs just being destroyed every fight. And the gearboxes are expensive,
motors are expensive, and so we decided to go down the route of uh servo pneumatics. You know,
we already like pneumatics, and Chomp's legs are controlled with air; position feedback loop air.
And there's a company in over on the east coast, Enfield technology that makes servo pneumatic
control systems and they sponsored us. Which is good because that is a bulk of the cost of the
legs is the control system. Yeah. This is a really unusual thing. This is not something
that even a lot of I would say engineers know about, that you can get a servo controller for a
pneumatic cylinder. So people are used to the idea of servo controllers for motors. But what Enfield
is doing is unusual and I'm kind of surprised it's not more widespread and more widely used,
because being able to... you know, not just have the cylinder go bang to 100 or bang to
zero. But say I want it to go to 45% and then stay there, or I want it to do this profile over time,
those are worlds apart and different in terms of how controlled emotion you can have. And then
Jascha's referencing robustness, if you um slam on the end of a geared system you might break
some teeth off the gears. But if you slam on the end of an air cylinder you just kind of compress
the air a little bit and then it's a spring and it doesn't really care. We thought about hydraulics,
they're not as back drivable they're quite power dence also but I mean,
I've done some hydraulic projects before and you have to want to be covered in hydraulic
all the time, because that's gonna happen. And you guys have chosen a design for Chomp that is very
defensive, honestly this bot didn't have to move if it didn't want to. Any legs that I have seen
they're never going to compete speed-wise with motors, and that's okay because from the beginning
we had this plan of putting a turret on. Where you win is you since you're at the middle of the
circle you don't have to actually pivot that fast to track somebody who's going around the
circumference. And it was so much easier to target the hammer on a turret, the turret is so much more
predictable than wheels. The classic like robot driving styles like overturn, overturn, overturn,
you know? You always turn too far because once you break traction you tend to have some momentum in
your turn. But the turret's just like a video game it's like points right where you want it to. It's
easy to go left and right whenever the target is just moving around a circle. And you can also have
different goals right? So with a normal driver and weapons operator system, The weapons operator is
kind of at the mercy of where the driver wants to go and be, and whether the driver can kind
of like get lined up but with this say that I really want to avoid the saw slots in the floor
I can go do the app and it doesn't affect Jascha. It's not like i'm stopping him from lining up for
a good shot. It's time to jump into the chomp versus Gamma 9 fight. What was you guys' a
strategy going into this fight with Gamma 9? Hit em with the hammer? Hit him with the hammer. Yeah
we knew there was no way we're chasing anyone down so the general idea is pretty much always
going to be... walk. We can pursue them slowly, and eventually they I mean you're not allowed
to avoid the opponent so we just chase you very slowly. Trying to avoid spots on the floor where
an arena hazard could get you. Those legs can end up down in a slot. Yeah. So and keep the hammer
pointed at them at all times I think that you can see the first 30 seconds I wasn't doing that and
then later I realized like there's no reason to ever have the hammer not. Anywhere else.
One of the big problems with the hammer is that when you swing the hammer, Chomp jumps.
And so, if I could resist the urge to swing the hammer, maybe they couldn't get underneath us,
but there's no way like as soon as they get close I have to swing the hammer. In BattleBots it gets
so crazy, sometimes you never know what hit does the trick. In the Gama 9 fight, you're on top
there's this dome, right? And you guys just chop, chop, chop. Most robots don't attack from above
right? So if you can be underneath someone, usually you're in like the glory position.
But with a hammer, especially a hammer they can spin around and point in any direction,
it's gravy if you're on top of somebody! Which we hadn't thought about it a whole lot,
and I think we realized that like halfway through the fight like, "oh... we don't
need to try to get off them. Actually, this is really good! it's not that they're underneath us
we're on top of them". I hadn't realized how far in hammer went. Yeah! Before I saw the video in
there. I think we were blocked, like I could we could see the back of Chomp. I just saw the
hammer was swung and it wouldn't retract, I'm like "that's probably a good thing".
It wasn't until we had a chance to breathe for a second I was like, "oh yeah, he hasn't moved
in like 20 seconds". A while yeah. So Zoe and Jascha, it has been amazing talking to you guys.
I cannot wait to see what Chomp gets up to in the rest of the season. And I hope to talk to you guys
super soon. Yeah lovely to talk to you! Thank you, nice talking to you. Always be Chomping! Chomp!
Chomp! Chomp! Chomp! Join us next time for more exclusive interviews on the HEXBUG YouTube channel
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