Virtual Event: A BattleBots Deep Dive with Riptide's Ethan Kurtz

Greg Paulsen: And Ethan made a quick appearance there, but we're very, very excited today. So my name is Greg Paulsen. I'm with Xometry. And today we are taking a BattleBots deep dive. This is a virtual event with team Riptide, including Ethan Kurtz, the driver. And we have a lot to unpack today. It's going to be such a cool event. Really nice Q&A session followed by a live Q&A here. 

Greg Paulsen: So before we get started though, I want to lay down the groundwork. We are going to start with some introductions and some background. And from there, we're going to jump into Q&A, questions surrounding all things Riptide and BattleBots. And now you, the audience, you also have an opportunity to submit questions at any time using the Q&A tab on the GoTo Webinar platform. I will try to get as many possible at the tail end of this hour. 

Greg Paulsen: So our goal is to kind of use next 40, 45 minutes for some really valuable Q&A time. And then we're going to take the audience questions for the last 15 minutes or so there. The thing that I want to say is this is a no spoilers discussion. This goes for team Riptide. This goes for anybody else when we're asking questions. We're not going to be covering any events or outcomes that have not already been published. So we've seen Riptide in a couple fights. We could talk about those, but not anything in the future fights. This webinar is recorded and we'll send an email with the recording for you to rewatch or share with your colleagues as well. 

Greg Paulsen: But like I said, a lot to cover today. Should be very exciting. Let's go ahead and get started. I'm really excited to introduce the team here and you all, also feel free to join on. You can now turn on cameras and mics and whatnot here. But yeah, we got…

 Ethan Kurtz: What's up guys. Greg Paulsen: It's going to be like... By the way, it's going to become Brady Bunch here. This is wonderful. Because we have team Riptide. So I'm going to start off with talking about Ethan Kurtz. And saying hello to Ethan Kurtz. He is the captain of the Riptide BattleBot team and is featured on the latest season of the BattleBots. So that's season six. Ethan's currently a student studying at the University of California, Riversdale. 

Greg Paulsen: So he's a young gun and he started fighting robots in high school. So what is that like a year ago? I don't know. No. But just really excited to have you on board. I also want to introduce Sid... I'm going to kill your last name. Prabhakaran. But I'm going to try. 

Stan Kurtz: Yeah. Help him Sid. Help him. 

Sid Prabhakaran: Yeah, there it is. 

Greg Paulsen: Prabhakaran. All right. Sid is electrical engineer, colleague and team member of Riptide, and he attends Texas A&M University. And actually you all met each other through competition, right? So you competed against each other in high school. Sid Prabhakaran: Yeah. I met Ethan during the world championships for VEX in 2018. So yeah, it was crazy. 

Ethan Kurtz: It was absolutely insane. I met [crosstalk 00:03:15 ] him... 

Sid Prabhakaran: We were a little more insane the year after, but the year we met you, you were definitely helping us during world's for our robot. I remember that. 

Ethan Kurtz: Oh, yeah. I was totally just thinking of the year after that, when you were just stupid and insane. He showed up with this fully just painted, beautiful robot and all of his autonomous functions were just so really, really, really fluid. It was like, I was just staring. I was looking at my little crappy robot, and Sid's very well thought out machine. And it was just so beautiful. I was like, "I got to work with that guy one day." 

Greg Paulsen: I love this here, you making a list. And speaking of that, I definitely want to introduce Stan as well. So Stan is Ethan's dad. But he is also teammate, part of team Riptide. And it is actually really cool. I was actually, I was telling Stan, I was moved about the story as a parent myself of getting your kid interested in stuff you're interested in, then seeing where he goes with it. So Stan welcome aboard as well. Just really excited to have this team and this perspective here. 

Stan Kurtz: It's a big privilege to be on the team and it's a big privilege to be with you guys. So thank you. 

Greg Paulsen: Yeah. And again, who am I? I'm Greg Paulsen. I'm the director of application engineering at Xometry and I'll be acting as a host and MC alongside with Simon Arthur, who is a Big Blue Saw. And Simon, do you want to give a quick introduction?

Simon Arthur: Sure. I'm Simon Arthur. I'm the founder of Big Blue Saw. And as of November 1st, I'm also the director of flat sheet cutting here at Xometry. Which means water jet cutting and laser cutting. And I'm also a former BattleBots competitor. I've been building fighting robots since mid '90s. Long time now. 

Greg Paulsen: Yeah. So he was part of the new season two, or if you're Comedy Central days, season four, five and six of BattleBots. So lots of fighting robot knowledge instantly gained through Xometry. And this is why this is going to be a really great discussion to geek out about. Simon Arthur: Yes. 

Stan Kurtz: Acquired him because he was a BattleBots guy. That's what happened. 

Greg Paulsen: When I got the meet Simon and the team down there, they're like, "Oh, yeah. And yeah, we fight robots too." And you're like, "What?" And it's really cool to see the passion, especially in this community and just how Ethan, and you and Sid were speaking. I mean, that's a theme that we're going to see in the next hour here is just the collaboration, the passion. Yeah, everybody's fighting each other with 250 pound robots, but it's so much more. So why is Xometry doing this? Why are we on Riptide's BattleBot and why are you all here? Xometry is a sponsor. So we do sponsor the Riptide team. And part of that is, Xometry is a on demand manufacture marketplace. We're actually the largest global digital manufacturing marketplace. 

Greg Paulsen: And we have some really cool tools that help people quote and get parts delivered to spec and on time. And I'm going to show you a demo of that in a moment, but just kind of to walkthrough what you're seeing on the slide, these are components and pieces that Xometry was able to help produce for team Riptide. A lot of aluminum chassis, machine plastic wheels, and even that gigantic weapon, the scariest thing in the world right up there. 

Greg Paulsen: So it's been really cool to be part of this experience and seeing these beautiful, pristine parts, flip eight, 20 feet in the air live on shows. So this is my pitch. I'm going to take the next, 1:50 here, but we're going to walk through a little bit about what this means though. So how does the team go about getting parts made through Xometry. And what's really interesting, we have instant quoting. So in that blip of a second there, you saw three machine parts get uploaded and priced out in seconds. It is a huge advantage. 

Stan Kurtz: And these are Riptide parts. You're actually using parts that were used on the bot right there. Greg Paulsen: Yeah. Some left and right brackets. That back panel, which I actually think has the Xometry silk screen on the back of it. But within the system, it's not just making the shape, you're able to configure, you're able to customize features. So in this case, I think these were aluminum here, but you could add if you had threads, tapped holes, if you need inspection reports, if you have different finishes or coatings, you could actually specify that within the Xometry instant quoting engine. 

Greg Paulsen: And we offer technologies from machining to molding, to casting, to 3D printing. And we actually have eight different types of 3D printing services. I wanted to highlight this little hub piece, because this is an interesting story, kind of talking into how Xometry has played a role, not just in making some of the parts, but also being part of the action. So this hub here, which Ethan has corrected me, because I did this for a demo. I chose raw plastic. But we would typically machine these for the wheels and they would've cast over them with urethane, but they were in a bind. They were between fights and had some broken wheels. And we were able to... Go ahead. 

Ethan Kurtz: Yeah. We kept shredding through wheels. After the Defender fight, we shredded through like four wheels. All of them were just destroyed from that pushing match. So it was like, we really needed more wheels quickly and we needed them fast and we usually get them manufactured in nylon, right? But that's not really possible to get within a day, no matter where you go. So what Xometry did is, they kind of ran the numbers and they're like, "Oh, if you 3D print it, UTLEM. UTLM. 

Greg Paulsen: Yeah, ULTEM. Yeah.

 Ethan Kurtz: ULTEM. ULTEM. That it's approximately the same strength and it's done by a real professional 3D printer, which you need for parts that are high stress. Because our little [inaudible 00:09:32] won't cut it in that scenario. So that was really, really nice to have that partnership in that moment to kind of save our butts so to speak. 

Greg Paulsen: Yeah. And this is the power of the distributed manufacturing. So what I showed you was the customer side of thing, which is kind of like this amazon.com. It takes what's usually eCommerce and now you can do it with custom parts. Parts that have never been created before. You can upload, get pricing, configure and buy very simply. 

Greg Paulsen: But we're connected to thousands of manufacturers. So we're able to respond very, very quickly because we don't run into a traditional single shop capacity constraint. Right? We're able to always work in parallel and also you're able to work with those sweet spots of manufacturers to get little miracles made if need be. So that's really exciting. That's part of what we're excited about here at Xometry. And I had to throw this in, and Ethan said, I'll let you all commentate on this, but I wanted... This is a video of the part still in its bare metal form before it got prettied up for the show, but this is some early testing, right? 

Ethan Kurtz: Yeah. So we started off doing a lot of testing early, since we're a new team, we wanted to make sure we had all of our minor issues that could really mess up a performance squared out immediately. So one of the things we found in this testing was... Yeah. 

Greg Paulsen: I'll pause for a second. 

Stan Kurtz: That's a 300 pound tire. So let's put that in perspective. 

Ethan Kurtz: Yeah. That is a 300 pound tire, but what's really interesting is you actually see the robot swerve towards us. Every time we hit the tire, which is really, really dangerous. And it was happening. We kept disconnecting when we hit the tire. Our receiver kept disconnecting. And that was one of the small minor issues we found. So through hitting a test load, we were able to find stuff out really, really fast. And that was really, just a great experience. 

Greg Paulsen: Yeah. It's really cool. And we'll get into that too, just talking about testing and iterations there. But we just showed some parts. We just showed some weapons and kind of showed what it does, but can you all break it down? So Ethan, what is Riptide to you all? Talk to me about the mechanical specs, material choices, just break it down. 

Ethan Kurtz: So mechanically Riptide is four-wheel drive and a single motor to each wheel, right? So it's a four-wheel drive, four motor drive. And it's an all-wheel drive. And the idea is that you can always keep moving and that's kind of what we built Riptide around was just consistency. And just always being able to quickly outmaneuver your opponent. 

Ethan Kurtz: And after that, it was like, "Okay, we have a pretty cool, badass drive now. How much weight can we shove into a weapon? What's the biggest, baddest, baddest weapon we could show to the world?" And so what we came up with was this 60 pound egg beater that's really wide and low to the ground. So we're able to pack high amounts of kinetic energy while being really stable and low to the ground and not gyring too much when we're driving around. On top of that, we've been really inspired by our mentors in Yeti. So we got the lifting forks of course, just to kind of supplement where we came from. So we got our lifting forks, badass egg beater, and an awesome drive. 

Greg Paulsen: And this whole thing is like [crosstalk 00:13:09]. Yeah, this whole thing is 250 pounds. Right? So this is the heavyweight division. So a picture does not really talk about the sheer size and mass, and actually 60 pounds for a weapon is kind of insane too. Ethan Kurtz: I think I've tried to just lift it up, or tried to flip it on its side by myself. It's just not possible. Sid Prabhakaran: No, very, very difficult. Yeah. You'd think that maybe you could budge it, but absolutely not. 

Stan Kurtz: This is one of the reasons why I think they keep me on the team is that I can carry some things. 

Greg Paulsen: Need some extra lifts. 

Ethan Kurtz: No brains, only strength. Stan Kurtz: That's right. It's all... I understand. It's okay. It's okay. You guys are the brains for sure. 

Greg Paulsen: And so Ethan you're on the mechanical, we're talking mechanical design and now, Sid you're the electromechanical. So you're the systems integrator. Tell me about what's some... Well, as much as you want to disclose about secret sauce, obviously. 

Sid Prabhakaran: Yeah, no, no. No worries. So our weapon is, obviously it's a 60 pound drum, but we need some big motors to power that or else it's not going to get anywhere. So we use two eight pound motors each for just our weapon and they're called Revolts. Each is about 11 kilowatts. So as a total, we're running about 30 horsepower just for the weapon. 

Sid Prabhakaran: And a weapon is really nothing without a really nice drive, I can get around the arena quickly. So we used four brushed Magmotors. So each one of those, or as a total, that's about four 14 pounds of just motors for drive. And so, yeah, it's a big investment in weight, but for us that was easily worth. 

Greg Paulsen: Yeah, this happens to be a weapon that has a vehicle designed around it. Is kind of what I'm hearing here. And I've heard the term, this is like a egg beater style, as far as the weapon goes, because it's rotated at very high speeds and moving around. And one of the things that we see when we see these BattleBots competitions, which are these heavyweight robots each with their own configurations fighting against each other is counters. 

Greg Paulsen: And so can you just kind of briefly go through, how do you configure this? Do you ever add wedges or anything to your bot for the fights and why would you do that? 

Ethan Kurtz: So, yeah. We were figuring that out as we were going, because originally Riptide was kind of designed to be all weapon all the time, kind of following up in our Yeti predecessors. And that worked to some extent. Again, it's huge. We were able to knock them out so quickly that we didn't really need a strategy. It just kind of worked. And our team just drove super duper well and everything just went to our small five second plan that we made before we went into the arena. 

Ethan Kurtz: So that was pretty lucky. And we were very prepared to do that, but at the same time, there wasn't much of a brawl required. So in the Defender fight, we later kind of thought, "Oh, yeah. We could just use our egg beater to fight into their forks." And that did not go well planned. We originally thought that we could just kind of angle at them and bite into them and that didn't really work out for us. Then we later figured out, "Oh, yeah. We can't just rely on our super powerful weapon all the time." We need to figure out better strategies. Greg Paulsen: By the way, is there anything that's spoiler here? Because I know we're up to Defender now. So I just want to make sure we're not giving [crosstalk 00:16:43]. 

Ethan Kurtz: I am careful. I'm being very careful. 

Greg Paulsen: All right. 

Ethan Kurtz: I'm usually very bad, but today I will be very [crosstalk 00:16:51]. 

Greg Paulsen: You can tease, but you can't spoil. 

Stan Kurtz: Defender was an awesome fight. Defender was an awesome fight. 

Greg Paulsen: I was going to say we have a nice gift at the very end during our Q&A session that people will be watching and loop and loop and loop and their eyes will be going up and down and up and down. 

Ethan Kurtz: Does that include me too? 

Greg Paulsen: Yeah. Ethan Kurtz: Oh, my God. That gift drive me crazy. Greg Paulsen: So let's move back. We're talking about what's present today, but I think what's really interesting is, you're coming on board as a rookie and there's history there. So let's take a stroll back in memory lane really quick. And if you can just tell me Ethan, how'd you get started? So how'd you first get into robotics and get that interest? Ethan Kurtz: So I think in the beginning, my dad kind of started me off with the RC stuff. So remote controlled airplanes. And I did that a lot as a kid. And so he'd give me... We'd build together these, $100, $500, meadowfoam planes. Which actually had brushless motors at the time, which was really interesting. But it wasn't as complex as it is now, but it's interesting that I experienced that so early. And I enjoyed that a lot. I got a good idea of what kind of competitive robotics would look like from that. I guess, because it's a lot of the same fundamentals that you taught me kind of carry... 

Stan Kurtz: And driving too, driving too. Ethan Kurtz: And driving yeah. I was a six year old maniac. 

Greg Paulsen: So Stan was training you as a driver, didn't even know it yet. So Stan [crosstalk 00:18:41] passion on the RC then, or did just happen to give him RC. So were you also flying RC planes and other stuff? Or you were just [crosstalk 00:18:49]. 

Stan Kurtz: Yeah, no. I started to get into it and wanted to get him into it as quick as possible. Because for me, I got into computers when I was really young and that was an advantage for me. I was using them before most people. So I was always trying to look at, "Okay, if I treat Ethan like an adult, what should I give him?" So I gave him planes that he crashed early on and that were expensive to crash, but after a couple crashes, he wasn't crashing anymore. 

Stan Kurtz: And so he was the youngest person on the field flying these planes. And that to me was just an advantage. Just to keep giving him responsibility, keep giving him things that other people weren't going to get. And I think when he was 12, we had him in the pilot seat of a Cessna flying us as a family. And then you just see him doing it like it's nothing. So it became nothing. So starting him early and giving him lots of responsibility and trust. That was my mentality. 

Greg Paulsen: Getting comfortable with the tech. That's awesome. And so Sid and Ethan, you were both, you did VEX Robotics, is that right? I also, there's FIRST robotics, but was VEX where you all got involved with actually the building and construction of robots? 

Ethan Kurtz: Yeah. So I think we both... Yeah, the first time I really got serious about robotics was definitely in high school. So I think Sid and I started around the same time, I want to say. 

Sid Prabhakaran: Yeah, think so. 

Ethan Kurtz: Early high school for you too, right? 

Sid Prabhakaran: Yeah. I started doing competitive robotics, so I actually started competing in VEX in sophomore year. And then I think I met Ethan at world's junior year and then from there for me, I did three pound combat robots on a smaller level during my first year of college and then kind of nothing for most of COVID. And then that's when Ethan messaged me and said, "Hey, [inaudible 00:20:48] going to BattleBots. Here's the plan." And yeah, I really liked the design and the philosophy. So of course I said yes. 

Greg Paulsen: And I think that's a great segue. So this is like, how is it a boy from Tarzana, California was given a chance to participate in BattleBots. So yeah, how do you go from a three pound fighting robot to, oh, the next step is a 250 pound BattleBot. 

Ethan Kurtz: We're men now. We're men. You can't call us boys. Stan Kurtz: You were a boy then. That's okay. Greg Paulsen: Okay. That was a quote from Stan. So that's why I put it in quotation. Stan Kurtz: He was a boy when he started. He became a man. 

Ethan Kurtz: Okay. So how did we get started? I think it's all very simple. So Sid and I both started in high school robotics and we knew of each other and I always saw him as someone who was just a brilliant programmer. So that's kind of how I got to find him. But more on just kind of the LA start. I did VEX Robotics starting in ninth grade. And from there I kind of sucked at it in the beginning to be honest. 

Ethan Kurtz: And then I just kind of started putting more and more and more and more hours. It was a school program. And when I first started, I was just like... I was just a normal kid. I mean, we say this airplane stuff, but I was just a normal, insecure ninth grader who played Clash of Clans and Clash Royale on his phone. I wasn't anyone special back then. And so I was just addicted to my phone. Totally addicted tomy phone. And I also was mildly interested in drones for some reason. And how that went is I pitched to my engineering teacher, "Yeah. We should start a drone racing club. And our engineering program and services." It wouldn't have been like a learning program, it was just some dumb idea. And he is like, "That's stupid. No, we're not doing that. Join the robotics program." [crosstalk 00:22:58] Yeah, he said it in the nicest way he could, but I felt very deflected. 

Greg Paulsen: So you kind of got ushered into the robotics program and it gave you some purpose. When did the BattleBots, the actual thought, like, "Oh, my gosh. We could do a battlebot." What does that even look like? And when did that start? 

Stan Kurtz: I want to throw one thing in that was I think really important about Ethan that I think people can know, is that Ethan talked about he was addicted to his phone. So when he started doing competitive robots or right before he really, really dove into it, he was realizing he didn't have his passion and his purpose and that he was even not even doing so well in school. Because he was really just kind of playing too many games. Not too many, but he was just playing a lot of games. 

Stan Kurtz: And we were supporting it. His mom and I were just supporting it. But one day he just said, "You know what? I'm done with this. I'm done with not getting my homework done. I'm done with feeling how I'm feeling and I'm quitting gaming and changed the password on my phone and I'm afraid, but I want to go full on into robots." And to me, that decision of being full on and saying, "I'm going to do this a 100%." And make that first step was the thing, I think that completely changed his life. 

Simon Arthur: Wow. And how old were you when that happened? Ethan Kurtz: I was like 14. So that was six years ago from now. And that's when I started really getting serious about this. I mean, before it was kind of like... I mean, six years ago, I guess I watched BattleBots when I was 13. I had a mild idea of it back then, but I had no idea where we'd be today. 

Ethan Kurtz: And basically though we got really serious about it. And I started doing robotics more and more, and I started getting really good at it. Sophomore year I was okay. Junior year, I was getting better. And then senior year was really the year I felt like I had it. We were winning the state competitions and the Google competitions just through me, just working my ass off. But eventually we won our California State Championship and we were fresh off of a Google win as well. Winning the tournament at Google. And I was like, "All right, we're ready to win the world championship at VEX Robotics. VEX Robotics World Championship. And COVID hit. Canceled. Boom. Bye dreams. 

Greg Paulsen: [crosstalk 00:25:29] senior year too. 

Stan Kurtz: Go on 

Ethan Kurtz: From there I'll sum it up. From there, we wanted a new goal. We needed a new goal. And it was like, "What's the hardest thing we could do? VEX World's got canceled for us. What's the hardest, next thing we could do? What's the hardest robotics competition out there?" And BattleBots was the hardest competition out there. 

Greg Paulsen: We were talking about this when we were prepping and we made a slide around this because we also reached out to social media and we're asking for questions and there's a lot of inspiration questions. I'm going to go to this next slide, but I really want you, like you and Sid, if you could walk through and just talk about, all right, let's do this. Let's do the hardest robotics fighting competition out there. What are my goals? What do we want to do? What difference do we want to make? And yeah, let's talk about some of those inspirations. The bot inspirations that you have. 

Ethan Kurtz: So leading into the competition, right? And after making the decision that we wanted to do this, we were watching season five after that. I had an idea of that I wanted to start a team and the general idea of the people I wanted to do it with. And Sid was one of them. But I still needed to figure out what type of robot we're building. Right? So at that time, Bloodsport and Endgame were two very prevalent robots in my mind. And they were doing extremely well in the season five competition. So we drew a lot of inspiration from Endgame. Just because their weapon was just a heavy hitter. And they were screaming through season five. Just knockout after knockout and upset after upset. So it was like, "Oh, yeah. We want a badass weapon." 

Ethan Kurtz: So that was kind of a given. So we drew a lot from endgame and our weapon system at least mechanically you'll find that emulates them a lot. At the same time though, we saw Endgame's ass get kicked by Bloodsport. It was not even close. And we were like, "Whoa. Who is this?" We know the Bloodsport guys. We know them from VEX. But we just saw that and we were like, "Holy crap. What are they doing right?" And part of that was their drive. Their drive just doesn't die. They don't stop moving. And that's Bloodsport for you. And they have this great four wheel drive using the urethane cast wheels and Magmotors for reliability. And they were screaming through the competition as well. 

Ethan Kurtz: Second seed as a second year team, that was just nuts. So those two robots for a heavyweight Riptide were kind of the main mechanical inspirations. And then you have more of the physical inspirations. So we started in the three pound division. And in the three pound division, we saw Lynx kick ass. And Lynx was just honestly on a completely different level of any other competitor we'd seen in the three pound division. 

Ethan Kurtz: And so going into the three pound division though, we went into three pound division knowing that we wanted to do BattleBots eventually. So we were just there to get experience. And we knew we wanted to do a four wheel drive vertical spinner. Sorry. I know it's the meta, but that's what we wanted to do. 

Stan Kurtz: No apologies. 

Ethan Kurtz: We saw Lynx do this. And we were just so amazed by what they were doing. And part of it was their weapon shapes. So it was like, oh wow. Egg beaters are really freaking good. The way he was using it and the way he was packing inertia led to really huge hits. So it was kind of a no brainer that we also really wanted big hits. So we were like, "How could we make an egg beater work on a heavyweight level?" And [crosstalk 00:29:40]. 

Greg Paulsen: And for context, this is a three pound bot in this picture here. [crosstalk 00:29:44] 

Simon Arthur: This is something you could just hold in your hand [crosstalk 00:29:48]. Unlike all the other ones. Greg Paulsen: [crosstalk 00:29:49] The pictures don't do this justice. We should have had a banana for scale Simon. As you mentioned. But this is a 60 pound weapon. This is a entire robot that's three pounds just for comparison, versus 250. 

Stan Kurtz: Yeah. You could put 10 Lynx inside the weapon and the weapon shape that's inside Riptide. Greg Paulsen: Yeah. 

Ethan Kurtz: It's [crosstalk 00:30:11] interesting. So yeah. That's where Yeti comes in. Right? Because we had all these really great ideas that we wanted to do, but they seemed really impossible to actually put into a heavyweight robot without... All of the first versions of Riptide, the first two CAD versions were 50 pounds overweight because we couldn't figure out how to make an egg beater that was strong enough to the point where it wouldn't snap. Right? 

Ethan Kurtz: So Yeti came in and they kind of taught us through their 20 years of experience what needed to be thin and what needed to be thick and what would break and what would not. And what wouldn't even get hit. So you don't even need to make it strong. So Yeti gave us this, just veteran's perspective that no other team really gave us. Which allowed us to basically avoid rookie mistakes. 

Ethan Kurtz: And just the basic problems that are plaguing first year teams. It's so common that you'll see a first year team, this beautiful, new, innovative design. It's flashy. It's cool. It's like nothing you've never seen before. And then they get knocked on their back in like first 10 seconds. It's like, okay. And we don't want that to be us. Right? And Yeti helped us let that not be us. Right? 

Ethan Kurtz: Because we had all of our kinks worked out so early because Yeti, Greg Gibson from Yeti just sat down with me on Zoom whenever he could. And he was just like, "This is sh*t. This'll break. This'll snap. This is totally wrong and won't work and you're going to go through a lot of pain. The belt system will work like this." There are things we couldn't get in CAD that he gave us through his knowledge. So we [crosstalk 00:32:17]. 

Greg Paulsen: Yeah. We call that tribal knowledge. And I think that's something that, as we spoke with you, as we've been prepping for this, I think that's just this whole sense of community because yes, you have Yeti as a bot, that's inspiration, but it's actually the team, right? It's the leaders of this that are willing to help and be like, "Cool. Let's make an awesome competitor. Let's pump Ethan and team up and show them how to make this work." And that's just so really cool. 

Sid Prabhakaran: If I could add. So yeah, obviously you don't really see that many designs like ours. Specifically the egg beater design hasn't really been done in a similar way to ours at least on the 250 pound scale. But Ethan and I have designed robots on our own, the three pound scale and we've gone through several iterations. 

Sid Prabhakaran: So one of our main, I think design priorities and principles early was, let's find out what we think will work on a major design scale and then innovate within the two kind of key stones. Which was reliability and power. So rather than making something that's super flashy, like Ethan said, we wanted to get something, a concept that we were confident would work and then innovate in the areas that teams usually choose second. Which is reliability and power. And so that's where a lot of our work went in, was picking this main design, locking it in and then working with Greg and a bunch of our other mentors and friends like Justin from Bloodsport and Shane and Jack from team Endgame. So yeah, that helped us a lot. 

Simon Arthur: So that egg beater shape on the weapon. It's got that hollow section in there. It's not like that just to look cool, right? There's a purpose behind that shape. 

Ethan Kurtz: Yeah. So the purpose behind that shape is that we're actually trying to put all the mass furthest away from the axle as possible. And that way we're storing as much kinetic energy as possible. So what you'll see in Riptide's egg beater is the parts that are pretty close to the radius are just hollowed out. And we only really had 60 pounds reserved for the drum. So we can't not have that hollowed out. And so the purpose was, how can we put energy far out from the radius to the point where we're storing energy, but also not so far out, like a Deep Six robot that we're constantly gyring and can't turn and maneuver. So the egg beater style was just, pretty no brainer when it comes to power versus drivability. 

Stan Kurtz: And there's a lot of design choices in even that egg beater. The angles and the shape of it. There's so many design choices that actually go into that but it looks to be sort of simple thing. And I think what's incredibly remarkable is when you see how it performs, a lot of people were surprised at... It just kind of looks like, "Yeah, there's a little egg beater." And the results are really remarkable. 

Greg Paulsen: Then it hits. And I think this is really cool because we were showing a little bit of your design parts. Right? So these design for CNC machine parts and some of these other tools, but again, you've done three pound bots. You know enough to be dangerous, but as we were speaking, you kept on mentioning generative. Tell me about your relationship with design. What design tools do you use and if you want to give it in your words, what generative design means and how you incorporate that into your efforts? Because this is new age. I mean, this is just really cool for me to hear from a college student being like, "Oh, yeah. Generative is just a everyday phrase for me when I'm talking about CAD." 

Ethan Kurtz: So let's be real. We aren't mechanical engineering... We don't have degrees. We don't have jobs. We are 19 year olds building heavyweight, insane robots that go on television and we get paid to fight other people. This is not... 

Stan Kurtz: Against the best of the world. Against the best in the world. Ethan Kurtz: It's the best in the world versus 19 year old kids. Stan Kurtz: Who hadn't gone to college yet. 

Ethan Kurtz: Yeah. We had to find our advantage and our advantage was generative for us. So what that looked like is robots take forces, right? And then they have to not break when they take those forces. So how do you design a part to take those forces without having experience and understanding how forces work. And what we did know is, "Oh, blade go to piece of metal, metal will react somehow." So we did know where the force directions work. 

Ethan Kurtz: And we did have an understanding of how that works. So what we did use is our understanding of technology to basically create generative maps or heatmaps or static stress simulations. And what that would show us is how do we reduce weight in our builds in a way that would also still be really strong. So if you look to left, you have our egg beater, static stress simulation. And if you follow the red path from the arrow to the circle. The circles would be where the bearings are. You could see that a lot of the red path is actually missing around the inner corners of the weapon bar. And that showed us that, oh, these filleted edges need to be a lot bigger in order for the bar not to snap. Because there's a lot of stress running through there. 

Greg Paulsen: Yeah. I've stressed along this internal edge here. So I got to beef this up because right now this has taken so much work in it. I see what you mean. 

Ethan Kurtz: Yeah. Yeah. So it was like, yeah, we need to beef that up. Because otherwise it would probably just snap. It looks like a super thin section in the generative, which means it is. And then on the right side you have just a structural [inaudible 00:38:44] inside the robot that also holds the motors. Right? And what you could kind of see from there, we didn't really get... So you could see all the triangles and that's my attempt at trying to do pocketing. And that was okay. It kind of worked. You could see the triangles are for the most part avoiding the static stress sections, right? The red paths. And it worked to some extent, but at the same time we realized through this simulation that we could drop so much more weight. 

Ethan Kurtz: That could ultimately be put into the bigger fillets in the egg beater. Because we were trying to figure out how we could build the weapon to be strong. And so we needed to drop every single gram and put it into a really huge weapon that also needed to be really well supported so it wouldn't break itself. So there's all these little details that Fusion 360 and other programs like the Xometry auto quoter would also teach us about machinability. All these little details added to what made Riptide great. We banked on other people's experiences to solve our own without knowing necessarily what we were doing. [crosstalk 00:40:00] 

Simon Arthur: So that stress analysis, that was Fusion 360? 

Ethan Kurtz: Yeah. Fusion 360, static stress simulations. 

Greg Paulsen: And what's so interesting here is, we were talking about this prototype to manufacturing to testing, but one of the things we always talk about with Xometry is you can't see quotes right away. And if you're using our CAD add-ins like the ones for Fusion 360, you can kind of see, "Hey, I'm adding a [inaudible 00:40:22]." And you can see your price updates. 

Greg Paulsen: So you can see whether or not it's a cost saving add or you could help make your value decision. But you're also simulating stress. So you're optimizing your design while also simulating price, while not paying anything yet. Or relatively. So I think this is really interesting that you're... This is like the ramen diet of good engineering practices here. You're using digital tools as part of your method and strategy, both from a pricing and a actual physics simulation standpoint. So I go, "[inaudible 00:41:03] chromogen." And then Simon's going to be like, "You can't be chromogen." But back in my day we just made the part and broke it. But that's... It's really exciting now to see this. 

Greg Paulsen: So, so on this, you talked a little bit when we showed that video early on, like kicking the tire there, but tell me what was the Riptide experience in brief from that prototype to testing to fighting ring. 

Ethan Kurtz: Okay. So because we are 19 year old, ambitious dummies, we decided that prototyping was a waste of time and we went straight to... Yeah, well, okay. Yeah. Like Sid said, "Well..." We did build a three pound Rival, which was kind of the general idea of what we wanted in Riptide. So Rival was this three pound combat robot, also with an egg beater. And we unearthed a lot of issues that we also found in Riptide as well. So one of them was, "Oh, yeah. Shaft bending." That's a big problem in egg beaters. Because egg beaters hit really hard on this long section. So you have to thicken up shafts and we kind of learned about how the general... So there's scale factor calculations that run with that, right? 

Ethan Kurtz: When you're building a three pound robot, you are able to scale some of the parts, right? So if you use a scale factor calculation, which is like, you're squaring each volume in three dimensions that gives you like a number, like the square root, the cube root of 250 pounds divided by three pounds. It's four or something. So if you thicken up things by that number, you would get parts that would really kind of work for your application. 

Greg Paulsen: It gets you there. It gets you in the ballpark, right? Yeah. 

Ethan Kurtz: Yeah. It's a good ballpark. Yeah. And from there we were able to kind of figure out, "Oh, this is definitely wrong." I think one part for Rival's egg beater was 3.5 inches. And then that scales to the Riptide for like 15 inches in diameter. Right? And I was just like, "Oh, God. That's really huge. No." So that only works to some extent. 

Ethan Kurtz: But anyway, after we kind of moved from that scale, we started recounting Riptide over and over and over again. Until we really felt like we got it right. And we also did that with the help of Xometry. So we did ask their engineers, how do we make parts cost less. Because we have no money. And you guys have experience. So we were able to talk to you guys about... 

Ethan Kurtz: We messaged Greg and all the other people inside Xometry is like, "How can we make parts that are more machinable?" And they were happy to help us. So we were able to kind of pull from Xometry's wealth of saving money into our own wealth, into the Riptide wealth. And that was really awesome. And that also helped us get parts produced faster, which we really needed to do in order to do well at BattleBots. So once we got our robot and all the parts earlier than we thought we were going to get them, we were able to test faster and figure out huge issues early in advance. Way in advance.

Greg Paulsen: I'm going to move us forward a little bit because I want to make sure we have time for questions. We're on the T-minus 15 here. But let's talk about the wink and the smile, huge issues here. So just kind of give me a day of, and then I have the clip of the fight that will play after this. But let's just talk about entering that arena. Just tell me that experience. 

Ethan Kurtz: So entering the arena, I think we were... It's really interesting because, and I've talked about this with a few people before. It's like, any issue that you have with your team or anything in your life drops. So any argument just goes and fades away, because it doesn't matter anymore. And you enter this place and there's lights hanging off the wall. There's people running frantically everywhere. It smells like sweat. It smells like nerves. It smells like crazy fans. 

Ethan Kurtz: And it's just this really interesting TD aspect you've never seen before. And that's really nerve wracking but also calming. And you also see your competitor. And so that was huge for us. And you're kind of like, "I have to fight that?" And originally, there was this serenity of, we're here and we made it. This was our goal and we're here. But at the same time, we're looking over to our left and we see Huge. And we're like, "I'm not sure we can win this one guys. This is our first fight. We're fighting this three year veteran." And I told the team before, it's like, "I don't like our chances, but we're going to do our best. And here's our strategy." And I think Sid and I were talking about it too, because Sid was pretty nervous is like, "Well, Sid. All you can do is keep that weapon spinning." 

Sid Prabhakaran: Yeah, not much [crosstalk 00:46:40]. I mean, it's hilarious because me and Ethan I think we've talked about it. We had completely different experiences going into the arena for the first time. For me, it was a lot more calm because there's really nothing I can do as a weapon operator. I can operate the weapon and I can keep it spinning with the [crosstalk 00:46:58].

 Greg Paulsen: Spin on, spin off. 

Sid Prabhakaran: Yeah, I can turn the stick up. But after that, it's really not up to me. So for me it was a lot more calming. I was a lot more in awe and just really excited to go into the fight. Where for Ethan, it was a little bit different I'd assume, and I know. 

Greg Paulsen: Yeah. And we're going to play the clip. And also I was going to say, I know the clip sometimes has been a little choppy on this run. I'm not sure why it is. But if we could get colorful commentary from both Sid, you and Ethan on this... But yeah, this is what they're talking about. This is the event. Their first fight. Season six, episode three versus the robot Huge. 

Stan Kurtz: I just want to say one thing. 

Ethan Kurtz: I just remember telling... 

Stan Kurtz: You had the logo there for Mouser Electronics. I just have to say this, that my company Accurate technology competes against Mouser. So as our first fight when I saw that, I'm like, "That's insane. That we're actually against..." It was just a weird chain of events there. So anyway, please continue. 

Greg Paulsen: Oh, it's funny because in my early life I spent about a year harnessing cables. So all I know is crimping and creating connectors with Mouser stuff. So all right. We'll get going. 

Ethan Kurtz: So what's really interesting before we start this box rush [crosstalk 00:48:19] go for this big slug. 

Greg Paulsen: I love that [crosstalk 00:48:23]. So your strategy was just bum rush him. You're like, "This is the plan." 

Sid Prabhakaran: For us. We really thought, okay, well listen. Huge is, they're obviously huge. And their design is meant to counter us. Their weapon sits above our entire frame. We cannot hit anything on their body except for their weapon. So we thought, okay, well our strategy should be, we should go in. We should try and stop their weapon with our face if we need to. 

Greg Paulsen: And the ref is telling you stop Sid. Do no more. By the way. 

Stan Kurtz: That's what he said. 

Sid Prabhakaran: So we were trying to basically stop their weapon or at least slow down their weapon and then keep on the inside of them. And that kind of worked as you see. Unfortunately, our weapon also immediately went down. Right after the second big hit. So if that hadn't have happened, it might have been a completely different fight. If what happened to Huge hadn't happened, it might have been a completely different fight. 

Simon Arthur: You see the weapon stop. Do you power down at that point or are you trying to get it going again? Sid Prabhakaran: So definitely I've tried to get it going several times. You generally, once I see my stick is up, but the weapon's not, I'll power down, power back up. I think I can remember this. Ethan was like, "Sid, get the weapon up." And I was like, "Well, I'm trying, bro." I have only one stick I can move. There's only one 5 stick I can move. But yeah, once I realize it's not coming back up, I'll tell Ethan and I'll power down just so we don't led anything on fire or overstress the motors or anything. 

Ethan Kurtz: I think I remember telling Sid right as we were going into this fight. I was like, "I'm going to close that gap as fast as possible. Please make sure the weapon is [inaudible 00:50:08]. Please." 

Sid Prabhakaran: Yeah. Yeah. 

Greg Paulsen: I did want to say here... We're going to get some questions ready. Because I want to spend at least [crosstalk 00:50:17]. Simon Arthur: [crosstalk 00:50:17] questions in. Get them in the chat box. 

Greg Paulsen: Yeah, use the questions tab in GoTo Webinar folks as you're watching this and I know we have a few coming in here. But the other thing is with this fight, you did go weapon the weapon. And I'm going to ask a question I saw on that, which is just, what is this made out of? Because I saw a lot of people were just surprised and I saw aftermath picture of this, which you don't really see really well. That there's a gouge in this thing. But just what's the weapon made out of, and because you just want to get... Huge's is S7, like a very hardened tool steal. 

Ethan Kurtz: Yeah. So there's one thing. I do want to quote one of my teammates, Brandon. After we got the robot back, we looked at the weapon bar and he's like, "I know we won but this is [inaudible 00:51:04]." [crosstalk 00:51:06] laughing because we're like, "Oh, God. So many repairs, but at least we won." 

Ethan Kurtz: But anyway, yeah. So Huge's blade is I believe water jet cut [inaudible 00:51:18] 500. So they run a 50HRC blade and Riptide actually runs 4140 steel at 45 HRC. So the problem, we're not running a high hardness because we're really balancing our weapons ability to not fracture. Because when you're putting together this [inaudible 00:51:39] egg beater, if you're fracturing your egg beaters during your competition and mid fight and you only have three egg beaters because that's all you can afford, what are you going to do if one breaks? 

Greg Paulsen: Yeah. And these are truly machine components. So versus a water jet. We were talking about this, but this is, it really is a precision machine component. It is surfaced. It is a giant chunk of 4140 that you're milling this from. You're not walking this to your machine. You're using your in shop crane to move it around. So yeah, it's definitely... It's good to have redundancies, but absolutely you want something that doesn't just shatter on you. 

Ethan Kurtz: So we'd rather it kind of chunk off and not crack. We'd rather it kind of get a little bit melted and a little bit more sparky than hold it's complete and utter shape. The dual disc on HyperShock's might. Just because we can't risk a fracture. Because it doesn't matter who you are, trying to get another egg beater made in two days is not... I mean, I'd love to see someone try. I don't know how we'd do it. It's such a complex piece of work. 

Greg Paulsen: And actually I'm going to, I saw this question when we posted on social here. And I mean, I'm going to start with this on the Q&A, because I think it's relative to the GIF. How does it feel knowing you flipped yourself higher than any flipper bot has launched anyone in 2020? 

Simon Arthur: That's an amazing flip. This is the highlight of the season. 

Greg Paulsen: Self-righting. 

Sid Prabhakaran: So this one is a little bit my fault. A little bit of a miscommunication here. Simon Arthur: What? No, no, no. This had to have been on purpose. 

Greg Paulsen: You just have [crosstalk 00:53:32]. 

Sid Prabhakaran: I wish it was on purpose. We've been trying to self right for, I think the 10 seconds or so, 15 seconds or so before this GIF happened. On the side of the wall, different areas that Ethan's driving around upside down, which is incredibly hard. Trying to get us some bite on something so we can flip us over Bite Force style. 

Sid Prabhakaran: And I'm seeing it, we're trying it. We're not flipping back over. We're kind of bouncing, we're coming back, but we're not flipping back over. So I decided, or I thought it'd be a good idea to bump it up from about like 50% where the weapon was at to about 70%. So a little bit of a jump. And right at that time, Ethan also managed to, instead of self riding on the, or running into the wall, Ethan was like, "Hey, the shelf looks like a great place to bite into. We'd probably get way better bite. We'd be able to flip over that way." 

Sid Prabhakaran: So yeah, it was a combination of Ethan driving into the shelf to get better bite and me turning it up to get more power that led to that I guess. And yeah, I mean to answer the question. It feels great. Would the fight have gone differently otherwise? Potentially. But [crosstalk 00:54:44]. 

Stan Kurtz: It was excellent television. 

Sid Prabhakaran: If we're going to lose [crosstalk 00:54:48], I'm glad we lost this way. 

Ethan Kurtz: Yeah. At least it gets a few million views on Instagram or something. I know what I was thinking when this was happening. I was just trying to get something I could bite into with the robot. And the I drive into the platform just kind of slowly, it then punts itself. I'm like... And then well, my first thought is, as soon as I get down, I need to go before Defender realizes what happened because [crosstalk 00:55:24]. 

Greg Paulsen: They're probably in shock at this point. Ethan Kurtz: Yeah. So Defender thought that the weapon would not work after that, but we were actually okay. And then we hit something on Defender, which led to a belt slipping off. And that's what took out our weapon. 

Sid Prabhakaran: Specifically what we found, and this is what I've... So what we found is a piece of the arena broke off and then hit the front panel behind our weapon. And then it bent into our weapon motors. And the only reason we know it was part of the arena is because we had red paint, on the inside of the front panel, on the front panel. In the one place it got hit. And the only red paint in that entire fight is on the shelf. It doesn't come from anywhere else. 

Greg Paulsen: Sid, on that question there, because this quasi has to do with this. For someone who's making a bot, they're looking for the electronics reliability, what control systems would you recommend? And actually, yeah, we have a lot of bot enthusiasts who are watching this right now. So do you have a recommendation for a control system? And that's a question from Harrison. Harrison who's watching right now. 

Sid Prabhakaran: I'm not exactly sure what they mean by control system. So for all the electronics for robots, for our robot, we prioritized making sure that we have reliability. We didn't want our robot to stop ever. So we used RageBridge's for the speed controllers for our drive. They're developed by Charles Guan actually. From Overhaul. Or... 

Simon Arthur: Overhaul. Yeah. 

Sid Prabhakaran: Yeah, yeah. And so that's what we use for our weapon, or for our drive. And then for our weapon we use VESCs and those are open source ESEs. That we bought the ones built and sold by Trampa. I hope that answers the question. 

Greg Paulsen: No, that's great. And honestly, I think it's really cool because you have this mix of audience who are looking to get into bot robotics and get technical. And this is super helpful. Now this is going back to just Riptide itself. I got a couple of questions. I saw on social and saw during this as well, but where did Riptide come from? What did the name actually come from? 

Ethan Kurtz: Oh, so as a kid, I was a fan of Percy Jackson. So what's really interesting. So Percy has his trusty blade Riptide. And it's this little pen that wraps out into the sword that's really dangerous. And I kind of related it also back to Riptide's kind of egg beater. It's this kind of little weapon compared to everyone else's that when it hits, boom. It's not something you just expect. 

Ethan Kurtz: So it's compact and not too visible, but when it comes out to play, you don't want to be on the other side of it. So Riptide and also we wanted to go through something water based to be related to the Alaskan Yeti. So that's kind of where Riptide came from. The name. 

Greg Paulsen: That's great. It's nice homage too, because you mentioned Yeti, not only were they there as a inspiration bot, but also as a mentor for you and your team. That's really awesome. Simon. I think we have time [crosstalk 00:58:57]. 

Stan Kurtz: One thing to say. Just a quick thing if I can add. Each of the inspiration teams that you saw in the slides, they all had captains, they all had teammates. And all those folks, they're all in touch. Ethan talks to them, Sid talks to them. It's really an amazing community where they're all sharing and competing against each other. And it's a real thing that happens behind the scenes. And you don't see it in business like that, but you definitely see it in robotics and you definitely see it at BattleBots. And it's really a beautiful community. 

Greg Paulsen: I was going to say, Simon's going to invite you down to Robot Battles down in hot land. 

Simon Arthur: Come on. Labor Day weekend, Robot Battle. We've got a lot of BattleBots people there and it's a nice break from having to do a two week robot competition. Something you can do in an afternoon. 

Greg Paulsen: So Simon I'll let you, if you look at some of the questions here. Is there any that we want to do? We could do one... We'll run a little over, but one or two more. Simon Arthur: Sure, sure. We have from Reddit. Do you plan on returning for season seven? 

Ethan Kurtz: Hell yeah. If they'll have us, we'll be back. 

Sid Prabhakaran: I actually forgot, because we did promise to reveal our next matchup during the webinar. And I think I would feel terrible if we asked people to join to find out, and then didn't tell anyone. So Ethan, you're closest with Greg. I'll let you handle this one. 

Ethan Kurtz: Oh, yeah. So who we're fighting next? I'm trying to think of something [crosstalk 01:00:40] ridiculous to say first, before I actually reveal to match up. Yeah. So they were like, "Oh, wow. You lost to Defender. Let's let's really drive in the screws and put you against Endgame and then Witch Doctor next." [crosstalk 01:00:56] 

Sid Prabhakaran: So yeah, so they saw us, at least from what I know... They first saw a really short fight with us against Huge. Where our weapon ran down. And then they saw us in a three minute bout, absolute slug fest with Defender where again, our weapon went down a couple of minutes into the fight, but we were able to drive to the end and it became basically a pushing match to the end. 

Stan Kurtz: And it was a one point fight, super close. Sid Prabhakaran: Yeah, very close fight. So our next fight is really a test of reliability. And to see if we're really these one hit wonder, or if we can slug it out just like the best of the best. 

Ethan Kurtz: That's exactly it. But what the producers wanted to figure out is, is Riptide reliable enough to make it into the round of 32? Will they, or won't they? So they put us against Duck. And at that point, what you'll see is who is more reliable and whoever's more reliable will get seeded and whoever is not, will not. 

Greg Paulsen: This is really exciting. And on that note, I think that's a really good way to end. I was going to say, Riptide, break 32. There we are on the [crosstalk 01:02:18] the logo. 

Greg Paulsen: This has been wonderful. I want to thank Simon as co-host and then team Riptide, Ethan, Stan, Sid, we're your greatest fans. It is just really amazing to see this. I am super impressed at where you are at, at your age right now. And using really modern engineering tools, using generative design, using the tools, the digital tools, digital marketplace manufacturing, to help you literally move along and optimize for just such a badass robot. 

Greg Paulsen: It's awesome. And I can't wait to see the rest of the season and how it pans out. But again, thank you so much. And also for the audience who's watched live as well as those watching the recording, thank you all again. 

Stan Kurtz: And Greg, thank you. Sid Prabhakaran: Thank You so much. 

Stan Kurtz: Thank you to Xometry for all the help and support that it's given Ethan as a boy from Tarzana, that they invested in as a sponsor and as someone that they spent time with to make sure was successful. 

Ethan Kurtz: A man. Greg Paulsen: A man from Tarzana. 

Stan Kurtz: All right. A man. 

Sid Prabhakaran: [crosstalk 01:03:31] Yeah. Thank you. And we really hope that everyone watching and if you made it the end of the webinar, then hopefully we get support from you guys moving forward. That's really important to us. 

Ethan Kurtz: Yeah. You're the real OGs if you made it to the end of the webinar. [crosstalk 01:03:47]. Sid Prabhakaran: Thank you guys so much. 

Greg Paulsen: Awesome. 

Simon Arthur: And you get that lovely discount code. 

Greg Paulsen: Oh, yeah. And Simon, reminded me to do my job here. Yeah, though I can't say that about 2TYRWEBB5 here, but there's a discount code for those who are looking to get some parts made, and even Riptide, team Riptide is able to use that code if they'd like. $25 off your next order of a $100 or more. Try out some new materials, try some 3D printing, get your machine parts. But again, thank you all. Have a wonderful afternoon or evening. Cheers. 

Stan Kurtz: Thanks. [crosstalk 01:04:20]. 

Simon Arthur: Bye-bye everybody. Peace. 

Sid Prabhakaran: Cheers, thank you. 

Ethan Kurtz: Cheers. 

Stan Kurtz: Thanks everybody.