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![Fifteen Years of Ask Aaron [Click Me]](pic2/Ten_2.gif)
Team Run Amok receives a lot of email about designing and building combat robots. In 2003 my son and team member Aaron Joerger (then 12 years old) asked for a question and answer page to document our responses.
Q: Hey Mark, I want to try building a sensored brushless motor powered lifter. I'm looking at a worm-drive gearbox with an additional belt-drive stage so I can just "park" the lifter with the motor unpowered and not worry about it slipping back down.
The motor I'm considering gives a "30-second Max Current" rating but does not provide a torque constant (Kt). Is there a way to calculate how much torque I can get from the motor at that 30-second current level?
A: [Mark J.] You're very brave to try a brushless lifter, but your plan sounds workable. You don't have the motor Kt, but I'm sure you have the speed constant Kv, so there is an equation that will give you an approximate torque level at a given current draw. I'd dial back the number it gives by about 20% to adjust for 'real world' conditions:
Q: I've upgraded my R/C system to a Spektrum DX6i and I swear that my bot is slower now. I'm using tinyESCs and Elevon transmitter mixing. The mix rates are set to 100%. Is there some setting I've overlooked? How do I get my speed back?
A: [Mark J.] This is a known issue with Spektrum Elevon mixing. Due to an error in transmitter firmware the two mixed channels each only provide about half the full travel response. You can bump the mix rates up to the maximum (125%), but that still doesn't get you all the way to full throttle. Here's the complete fix:
Alternate Solution - If you'd rather not fiddle with the transmitter, you can change the response of your motor controllers to provide full throttle at the lower signal level. Follow the calibration procedure on the setup sheet that came with your tinyESCs.
Q: That's got it! New question. My DX6i transmitter is currently powered by four AA alkaline batteries, but I have a spare 2s lipo battery that will fit inside the battery compartment. Can I patch in a matching connector and power my DX6i transmitter with the rechargeable 2s lipo or would it be too much voltage? A: The Spektrum transmitters have a wide range of acceptable voltage input. I'm told that they will operate without issue from 2s, 3s, and even 4s LiPo packs. So, you can do it, but the capacity of a LiPo small enough to stuff into that battery compartment is going to be pretty small compared to a set of high-quality, low self-discharge NiMH AA cells. Q: I know this is an odd question, but do blades with curved edges tend to get better bite or any other benefits, or does it just sacrifice a lot? For context, I'm referring to a blade with a slight curved indent into one side, somewhat like a scimitar or other related weapon.
A: [Mark J.] 'Bite' is a very specific technical term when referring to spinner weapons. As defined in the Ask Aaron Spinner Weapon FAQ:
Q: I could not find any mentions of a weapon type my team is considering using in the 15 lb weight class. Our design is utilizing a spinning shell around a stationary core, with 3 portions of chain from a chainsaw with weights on the end. The chains are going to be short enough to not be considered an entrapment device.
The purpose of the weapon would be to create a nice barrier between their weaponry and our shell, while still either bludgeoning them with a weighted end on each chain, or potentially cutting into them with the chains. Do you think this would be a valid primary weapon?
A: [Mark J.] Weighted chain weapons are a type of 'flail'. The BattleBots Wiki has a category page devoted to robots armed with spinning flails with photos and links. Chain flails were fairly common weapons in the early days of combat robotics, but builders quickly learned that rigid weapons were much better than floppy weapons.
There are several 'flail' posts in the Ask Aaron Robot Weapons archive. In the box below I've re-printed an archived post that sums up their performance issues.
A: [Mark J.] If you perform a numeric analysis on flail weapon performance it's quite clear that the ideal chain length is 'zero'. An effective spinner weapon stores kinetic energy and delivers that energy in a single massive impact on your opponent. Flails swing out of the way after striking and transfer only a fraction of the energy stored in the spinning mass of the weapon -- it's like trying to hit a home run with a rubber baseball bat. Solidly mounted hard 'impactors' have proven to be much more effective weaponry.
There has never been a successful flail robot -- either vertical like 'Morrigan' from Near Chaos Robotics, or horizontal like 'Chains Addiction' -- and I don't expect to ever see one. The only thing they do well is make noise. Avoid.
Q: I believe you just saved my team a LOT of time, I appreciate it! -Flail idiot A: You're welcome. Don't be hard on yourselves for finding this design appealing; many teams have gone down this same blind alley. Q: What is it about [insert robot name here] that makes it so dominant? Is it the weapon? Is it the armor? Is it an ultra-sharp wedge? Is
A: [Mark J.] Let's say that you're going to jump out of an airplane at 20,000 feet. Which of the following features do you want your parachute to have?
A robot like [insert robot name here] is built and maintained by a team with the talent, experience, dedication, and funding needed to cover all the bases. And no, they don't cheat.
Q: I want to run the weapon in my new beetleweight at 6s [22.2 volts] but that's crazy high for my drive motors. What's the best way to reduce the voltage to the drive?
B) A 12V step-down voltage regulator?
Can I do this without creating a ton of heat?
A: [Mark J.] The correct answer is
Alternately, if you are using transmitter Elevon mixing you may limit throttle response by setting the Elevator (channel 2) response to less than 100%. Start with 50% and adjust as needed to tune the drive motor performance to a suitable level.
Q: Hey Mark, I've taken up the helm of my university's Beetleweight team and we are building a new robot this year. We built one last year but it was a wedgebot and essentially a crash course on how not to build a combat robot: we went way over the weight limit, 3d printed a chassis, and haphazardly threw some silver spark motors in there. Surprisingly enough it ended up working but thankfully I had the foresight to never enter it into a competition.
Now that I'm at the helm, we're currently working on selecting drive motors. Of course, we want something that will supply sufficient torque and speed, but isn't too heavy. But what exactly should we be looking for in a motor? I've seen websites give information on motors such as their size, weight, KV, stall and no-load torque, and max. current limitations, but how do we use all of these statistics to compare motors to each other to determine which ones fit our needs best? What kind of calculations can we do to determine the needs for our purposes? I've seen calculators on this website relating to the max. current draw and gearbox selections, but that assumes that you've chosen a motor and as of right now that seems to be our first roadblock. I guess another question is, what are some good vendors for the beetleweight class motors? I've seen Fingertech, BotKits, KitBots, and then there's also RobotShop. Do you have any other recommendations for that? Just to avoid a bad hamburger, I'd like to mention the following:
Thanks, Bengal Reauxbotics
A: [Mark J.] You've taken on a leadership roll for a complex project but can't find an hour to scan thru our website? That time would be well spent in finding not only the answers to your current questions but multiple nuggets of information you haven't yet realized you need to know. Asking for a shortcut handed to you on a platter does not bode well for your new robot, but maybe you'll learn something from a second failed robot that you didn't learn from the first.
Here's your shortcut:
This all assumes that you're going with brushed drive motors -- which I strongly recommend given your level of experience. If you're set on being cool brushless drive hipsters I'm afraid that you'll have to carve a good chunk of time out of your busy schedule to read up on that option -- there's way too much on that topic to summarize here.
Q: Hi Mark, 3lb Flywheel flipper guy again. For a section of my loading mechanism I'd really like to use a motor in such a way that it could end up taking a pretty serious shock load (the residual energy left over after a flip, or worse, a missed flip's energy). The motor will need some decent torque and very low speed. To give a perspective on torque requirements, I'm essentially using this 2nd motor attached to the flipper arm mechanism in such a way that it can be used to drive the arm almost as a lifter bot. This would normally would lead me to a gearbox, but given the shock situation I'm left looking for a direct-drive system where the motor can be back-driven.
It seems my quest is not without a solution at least. On Battlebots the main arm of Jameson Go's SawBlaze has had more than a couple instances of aggressively snapping back after the heavier vertical spinner style 'saw' blade takes a bite and seems to work just fine. That's also chain driven, though I can't find any info on the motor and gearbox combo used other than his 30lb version megatRON uses Banebots P60 planetary gearboxes on RS550 motors to do the same job (can't tell if there is some kind of slipper clutch in there though too?). Also, whatever DUCK! is using this season for the flipper arm drive motors are quite clearly just fine with being back-driven with some serious shock. Any guess as to what Hal is using in there?
Hopefully one of my many assumptions is just blatantly wrong and there is a simple solution, if not, it's back to the drawing board for my design. Thank you very much for your time!
A: [Mark J.] I'm not getting a good picture of your design from your description. I'm guessing that you're trying to raise the flipper arm up just a bit with the lifter motor to engage some type of dog clutch on the flywheel and initiate a 'flip' -- but I don't understand how residual flywheel energy would backdrive such a system. Have you read thru Dale Hetherington's Flip-o-Matic page? Regardless, if that's what you need let's see what we have.
Q: I'm building an antweight with a lifter plow, kinda like 'Duck!'. The lifter is powered by twin servos that need to run in opposite directions to work together on the lift, but my transmitter only has elevon mixing and I'm already using that for the drive motors. I have a Y-harness to connect both servos to a single receiver port. Can I re-wire one servo to respond in the opposite direction? A: [Mark J.] I can save you a lot of time and frustration. R/C airplanes have a similar problem getting the twin servos controlling wing flaps to respond in opposite directions, and they have a quick and simple solution to the problem. A web search for "servo signal reverser" will reveal multiple sources for a tiny, inexpensive device that plugs into a servo lead and reverses its response. Do that! Q: I kind of need some help here. I have a drum weapon beetle and my scorpion mini esc kind of turns off sometimes when it gets hit. We use two 12v polulu motors for the locomotion and a propdrive 1200kv with a flycolor 36A esc for the weapon. The battery is 3s 1000 mAh. We are sure that the problem is not the connections and its not shortening anything.
Even when the locomotion is not working, the weapon still runs nice. When I turn the weapon off and on during the combat, sometimes the locomotion comes back. Does it have anything to do with the electrical noise or some kind of interference in the receiver?
Q: Is there a difference between the D-Pack gearbox and the Magmotor gearbox?
A: [Mark J.] The 'D-Pack' was an industrial hydraulic pump motor similar in size to the S28-400 Magmotor. In the early 2000's the D-pack was available from surplus dealers for a very reasonable price and found use as both drive and weapon power in a number of combat robots. The mounting face and hole spacing are different for the two motors, so gearboxes for them reflect those differences.
Q: This is something I’d like to tack onto the previous question, but I’ve heard people online saying “shell spinners are obsolete”. What do you think? Do you think that these designs have no place in the future? What other designs might one consider obsolete (besides hammers, but don’t let Al Kindle know I said that).
A: [Mark J.] I'm gonna pass on this discussion. I already get enough hate mail for discouraging builders with new ideas. If I start talking builders out of old ideas there won't be anything left.
"Prediction is very difficult, especially if it's about the future."
- Nils Bohr 
Q: So here’s a question: there was a Chinese competitor called... Flame Wheel? Hot Wheel? Not for sure, it’s one of those two names. Anyways, I was wondering if there’s any advantage to having the [impactor] mass placed outwards like seen in this picture in comparison to having small, sharp teeth like Gigabyte or Captain Shrederator.
'Flaming Wheel' had two interchangeable spinning shells:
The unusual design of the tall impactors does provide strong support that also keeps impact forces away from the clylindrical shell itself, but the impactors are placed in a position that is shrouded by the gradual taper of the top and bottom mounting plates. The impactor itself needs a clear shot at the opponent without any material in the rotation path that might tap the target out of the way. I don't know what the "bite" calculations for 'Flaming Wheel' look like, but there is nothing to gain by adding material that can get in the way of your impactor path.
Energy storage advantage? Minimal.
Q: I have a choice of two versions of the same brushless motor to power my weapon: a 750 Kv and an 1100 Kv. The 750 Kv version will give me more torque, right?
A: [Mark J.] There are a lot of 'half-truths' about brushless motors floating around out on the 'net that are confusing robot builders and leading to poor design choices. You can find this one all over the 'net:
There is a kernal of truth in that statement, but it is incomplete and misleading.
The true part -- the motor speed constant (Kv) and torque constant (Kt) are inversely proportional -- if one goes down the other goes up. Compared to a higher Kv version, a lower Kv motor will produce more torque per amp of current.
Here's a real-world example comparing two versions of the AXI 2208 motor:
The incomplete part -- lowering the motor Kv increases the electrical resistance (Ri), which reduces the current the motor will draw. The misleading part -- if allowed to pull unrestricted current, the lower Kv motor version will produce both less torque and less power.
AXI 2208/34 Gold Line V2 motor
AXI 2208/20 Gold Line V2 motor
The 1820 Kv version of this motor generates greater torque than the 1100 Kv version throughout the RPM range. When bogged down to the '60 second' current maximum it produces 8% more torque, and it does so while spinning 85% faster than the lower Kv motor -- a power increase of:
There are a number of reasons why you might choose a lower Kv version of a motor for a specific application, but Q: Hi Mark, I've been working on a flywheel flipper design for a while now (I know, I know, get your cheerleader button ready but hear me out first...) I want a high-power flipper that can manage proper ceiling-hitting throws not just a lifter in the 3lb class. I don't have enough experience with pneumatics to be comfortable with a DIY solenoid setup and in the 3lb class it seems like there aren't many part options off-the-shelf for big power done safely at low weight. 'Kelpie' and 'Launchpad' are two options in that class along with 'Anticide' even smaller so while it isn't impossible, it's not the challenge I'm stuck on. There are a couple small flywheel flippers that seem to work well, though not many THAT small, likely for good reason, but I've convinced myself it's not too far-fetched. All the flywheel flippers I've found seem to approach the task in a different way. The lack of a tried and true method yet multiple successful solutions really peaks my interest. I also think this question might directly relate to spinner weapons so the answer may be useful for people who aren't directly in need of a cheerleader button. My question stems from this previous post:
Q: Hello, I was curious as to how friction and RPM relate to each other when talking about a spinning weapon? If I increase my RPM to increase energy storage will I also loose more energy to friction in the process? Also, is this increase linear or exponential?
In the answer you mention Aerodynamic drag:
If your weapon is a thin disk that displaces little air as it rotates this isn't too much of a problem...
I'm trying to quantify 'too much' and see at what point i'm doing extra math and making the design more difficult/less reliable to add a fraction of a Joule to a multi-hundred Joule system. For my flywheel I could see about making it in a variety of different ways. Assume all options weigh the same:
This question is more hypothetical out of curiosity of the math, but to avoid being a bad hamburger my intentions are a 6-7" wheel weighing just under 1lb. I have not yet selected a motor option because I'm not far enough along in the design process but Silent Spring uses an AXi 2814 (1390kv I think) on a 4s lipo to power it's similarly sized disk so lets assume that ballpark.
A: [Mark J.] Let's have a look at the rest of the sentance you reference from my reply to that earlier post:
Q: I'm investigating using brushless drive on a 3-lb Meltybrain spinner and I was wondering if you had some advice on picking motors. I've only used brushed in the past, which is a pretty straightforward process with a torque calculator. However, I can't seem to find any analogous tools or equations for brushless motor torque.
It seems like people have had success with the DYS BE1806 and AX-2810Q, but simply based on the motor characteristics on HobbyKing I don't know what makes them better than others. I know that a lower Kv means higher torque, but how do you know that the Kv is low enough to drive your bot?
A: [Mark J.] You won't find drive train tools analogous to the
Tentacle Torque Calculator for brushless motors because brushless performance depends as much on the controller firmware as on the motor. All the possible combinations are staggering in number and largely theoretical in practice. The way brushless drive is done is to go for overkill and not worry all that much about the details. See this previous discussion in the Ask Aaron archives: Brushed vs. Brushless Drive.
There's a "rule of thumb" for brushless motors circulating out on the builder forums that appears to work well for drive motor selection. The rule states that a set of brushless drive motors together weighing between 2% and 3% of the total weight of the robot will have more than enough power and adequate 'thermal mass' to survive. By that rule a pair of DYS-BE1806s is about right for a beetle. Twin AX-2810Qs qualify as huge overkill and are used quite successfully by pictured beetle melty spinner 'Halo'.
What makes a motor better than others? Somebody used it successfully on their robot and word got out. Brushless meltybrain spinner? You're on your own. Best luck.
Q: Set screws on my insect-class robot hubs are driving me crazy. They won't hold!!! All I've got is hand tools. Is there anything I can do to make my wheel/gear/pulley hubs more reliable?
A: [Mark J.] The tiny set screws as supplied with small hubs are generally inadequate to reliably hold against the forces imparted by robot combat. Exotic clamping/splining solutions that can eliminate the problem require custom machining. But don't despair -- it is entirely possible to massively improve the reliability of set screw hubs using only hand tools. Follow along:
Q: Hey its me from Anacortes again. First I want to thank you for diagnosing the BEC problem with my ESC [two posts down the page]. I never would have figured it out on my own. Anyway, now that I've had some time to reflect on the untimely demise on my ESC, and the fact that I'm way over budget, I'm ready to look for a new ESC. Now, I've seen that some builders seem to be able to save space by using two basic ESCs rather than a single dual ESC. Knowing that I will be running four Kitbots 1000 rpm gearmotors on a 4s lipo, and using a BEC, would you recommend this? [Anacortes, Washington]
A: [Mark J.] You aren't using the on-board mixing or BEC on the Scorpion Mini ESC so your replacement can certainly be more 'basic', but your beetle wedge doesn't seem to have any space problems. Some of the commonly used single channel options won't handle a 4s LiPo battery so you may have limited choices. What ESCs are you considering? Q: Well that's the problem, I actually do need more space in my robot. (I will be getting a smaller 4s battery, 1500 mah is just to practice.) But as far as ESCs, I don't really know where to start. I know this isn't a free engineering service, but could you please try to point me in the right direction?
A: There aren't a lot of choices. Take a look at this post in the Ask Aaron 'Ants, Beetles, and Fairies' archive for a list of available options and a discussion of the cheap Chinese solution.
A: Current draw is dependent on the load placed on the motors, not the number of motors:
You can run this thru the
Tentacle Torque-Amp Calculator for verification. The distributed version of the calculator does not include the Kitbots motor in its pull-down selections, but I use the following motor settings in my personal copy:
Q: I'm reading thorough The Variable Constant's Guide to Vextrollers and I think I get the gist of how to follow his instructions to hack each individual one. Now I have 3 questions about next steps:
A: Three answers...
If you examine the receiver connector on the VEX you will find the little barbs that hold the connector pins into the plastic holder. With a small probe you can unclip the barbs for the red and black wire pins (video), pull them backwards out of the holder, clip the pins off, and they're ready to connect to the battery. Leave the white wire and pin in the holder and plug it directly into your tinyMixer.
Q: When two wedge/ramps meet, what design choices dictate which gets under who? Is it the length of the wedge? The high? How heavy it is? I mean other properties that help clearance with the ground but still don’t get stuck to the uneven floor?
A: [Mark J.] The saying goes, "You can't have your cake and eat it too." You can't have a razor-edged paint-scraping wedge and still not get stuck on a raised floor seam. The best design for getting under wedges is actually something other than a wedge.
A wide single piece dragging wedge will ride along the highest part of the floor it contacts, which leaves the rest of the wedge spaced above the arena surface. Multiple hinged 'wedge killer' forks have a good chance of riding down in a lower section of the arena floor and slipping under a wide wedge.
Get to know the arena you fight in. Learn where the bad floor spots are and make a habit of running across the floor seams at an angle where you can. If you're still getting stuck too often, feather that sharp leading edge just a little.
Note - I've edited this post to remove a lot of back-and-forth questioning and general confusion about what was actually happening with the robot. The names have been changed to protect the innocent, but the outcome remains the same.
Q: Hey, its me from Anacortes again. I've run into a couple more hitches in the electronics of my beetleweight wedge. A while back you basically had to walk me through how to install the fingertech tinymixer properly, and at the time it seemed to work fine.
But now that I've put the chassis of the robot together, the right side drive motors suddenly reverse direction for a split second when I use more than 75% throttle. This happens every 1-3 seconds of drive, making it largely uncontrollable. I suspected that the tinymixer was the cause, and sure enough, when I removed it the motors responded to power normally. I wanted to get some driving practice in, so I was just driving it around when the RX battery alarm went off on my FS-i6 transmitter and the robot became unresponsive. The transmitter RX battery display shows no bars and the speed/direction lights on the Scorpion are not responding to transmitter inputs. Is this some sort of hardware problem, or is somthing wrong with my setup? I'm running four kitbots 1000 rpm gearmotors with Scorpion mini esc and a 1300mah 95C 4s lipo. [Anacortes, Washington]
A: [Mark J.] Your FS-i6 radio is bi-directional: the transmitter 'talks' to the receiver, and the receiver sends telemetry (like the voltage level at receiver) back to the transmitter. That telemetry function causes the receiver to draw a lot more power than a passive receiver.
I looked up the specs on the BEC output for your Scorpion Mini. Its max output decreases with increasing input voltage to the Scorpion:
Q: Ok so it just so happens that I have a BEC laying around. I jerry-rigged it to the wiring to power the receiver directly and removed the red wire power pins from the Scorpion receiver leads. The low-voltage alarm has stopped and the RX telemetry bars are full, but the robot still won't move. Any thoughts or ideas? A: Patching in the stand-alone BEC got power back to the receiver and restored operation of the radio system, but the Scorpion ESC is internally powered by the output of its own BEC and that has failed. You can try re-connecting one of the red power wires from the Scorpion to the receiver to see if you can back-power the ESC circuits. I don't think it'll work, but it won't take much effort to try.
I'm working on the designs for an antweight (US) lifter, and was running the calculations of using a Silverspark motor to power the weapon. However, the math seems to be a bit... off. Here's what I have:
Maximum Lifting Weight: 2 lbs
Maximum Torque at Gearbox (ft-lb):
Max Load At Gearbox (in-oz): (.66 lb-ft x 192)
Motor Stall Torque: 0.64 oz-in (Fingertech Silverspark @ 6v)
Torque Overage Factor: 2
Gear Ratio Required: ((126.72 / 166) x 2) = ~1.5:1
Also, I plan on running the motors at 12v - 14v rather than the recommended 6v. How does this affect the stall torque, or does it remain constant regardless of the amount of voltage applied to the motors? [Newton, Illinois]
A: [Mark J.] You were doing fine right up to the end. That last line should be:
Stall torque, stall current, and no-load RPM of a brushed PMDC motor increase proportionally with voltage. Increasing voltage from 6 volts to 12 volts will double both the speed and the torque of the motor, so your new calculation will be:
A: [Mark J.] I do not take such liberties with ballots for the Hall. I simply count and report on all the verified ballots as submitted.
I've learned that forum chatter is a very poor predictor of Hall balloting. The 'D2 Kit' in question is 'Captain Doom', a 'bot popular in both UK and US balloting because of its success in the UK Bugglebots web-based mini-series and multiple US competitions. Several Bugglebots competitors showed up in the 2019 balloting.
As I dutifully reported, 'Captain Doom' appeared by name on more than 10% of the ballots received for 2019.
A: [Mark J.] Changing the material of the FingerTech vertical spinner blade from Grade 5 Titanium to AR400 Steel would result in a heavier, stiffer weapon that would in fact 'hit harder' -- but the improvement would be too small to help this specific weapon.
A: [Mark J.] To quote the Grateful Dead, "Lately it occurs to me what a long, strange trip it's been."
I could write a book on this topic, and anything less would not do the topic justice. Until my book comes out you should find and read a copy of "Gearheads -- The Tubulent Rise of Robotic Sports". Here's what I say about it in my book review page:
It's all here -- the early Robot Wars competitions in San Francisco, the clash between the creative and business aspects of robot combat, the legal turmoil, the personalities, the excitement... I locked myself in a quiet room and read the book cover-to-cover. Food crumbs on the pages mark where I grabbed a quick snack while continuing to read!
Anyone with an interest in the story behind combat robots needs to read this book. It is a fascinating read, and does a fine job of keeping all the parties involved very human. Highly recommended!
The 'Ask Aaron' project was important to Aaron, and I continue the site in his memory.
Thank you for the many kind messages of sympathy and support that have found their way to me.
Aaron's obituary
Q: how can robots help us deal better with hurricanes and why? [Ontario, California]
A: [Aaron] Few people in Nebraska are threatened by hurricanes, so send a swarm of killer robots into low Atlantic and gulf coastal areas to drive the puny human inhabitants toward Nebraska. Problem solved.
Robot haiku:
Type your question in the box, attach files if needed, then click: 'Send'
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Even small combat robots can be dangerous! Learn proper construction and safety techniques before attempting to build and operate a combat robot. Do not operate combat robots without proper safeguards.
Q: My question this time involves flails. Simply put, what chain length to flail weight ratio is the best? Also, why has nobody ever mounted flails vertically, like on a drum or a flywheel? Finally, would a horizontal or vertical mounted set of flails do best? [Urbana, Illinois]
A: [Mark J.] I'm gonna bet that you have the 'Lipo' jumper in place on your Scorpion Mini ESC. The Lipo jumper activates a circuit that will shut down the Scorpion Mini output when your supply voltage drops below 3 volts per cell -- even for an instant. Here's the event sequence:
A: [Mark J.] The robot is King of Bots season 2 competitor 'Fēng huǒ lún' or 'Flaming Wheel'. An unrelated robot fought in King of Bots season 1 under the name 'Hot Wheel'.
A: Yea, the ESC is toast. All that heat is coming from the charred remains of the former BEC still trying to do something useful and mostly just turning current into heat. Here's what you do:
Q: Hey there, Mark! This might be a dumb question, but I'll ask it anyways. Over on Facebook people mentioned the 
Q: Hey Mark. It's been 25 years since 
