BattleBots Tombstone Weapon Motor Modifications

This is outlining the weapon motor that we use, and the modifications that I have to make in order to survive combat! We're continuing to get Tombstone ready, for matches later this year at BattleBots Faceoffs!
battlebots.com...
Keep watching, as we get Tombstone ready to face some high energy opponents later this year!
Ok, this seems to be a recurring thread through the comments, and I get it that nobody but me will read through all the comments for my answers. Nobody is going to read it in the description either, but here goes anyway! This has to do with motor cooling.
The redesign of the motor mount removes the small internal fan, and the cooling slots through the top of the motor. And everyone (seriously EVERYONE) seems to think this is why the motor overheated. So, let me give you more specifics here :) We have a lot of matches under our belt with this layout for the weapon motor - this is not untested engineering. If the robot has a tough match, and has to spin the entire 3 minutes long, the motor does not get overly hot. It's warmer than room temperature for sure, but you can lay your hand on it easily. So why did this particular motor overheat so badly? As I mentioned in the video, this robot burnt to the ground. This is not an exaggeration really. We had a significant lipo fire in the robot, that burned for 20 minutes in the arena. We lost everything internally, with fires hot enough to slightly melt some interior aluminum panels. The lack of cooling slots in the top of the motor played no part in this, and in fact probably made it harder for the flames get into the motor. Also, an enclosed motor is less likely to get arena debris inside of it, which is a way bigger problem than most people realize. The solid motor mount with no cooling holes wasn't an oversight on my part - it was a deliberate design decision which has worked very well.
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[@tonybebb72]

"Things started breaking because people started hitting me back." 😂

[@BotvacProductions469]

thats honestly not that funny

[@overchug2933]

honestly thats pretty funny

[@BotvacProductions469]

every video Ray posts brings a riot of supporters and well-wishers. Ray made this sport into what it is today, and thats a fact! Tombstone is always entertaining, win or lose! keep doing what you do Ray, and dont let anyone say otherwise!

[@ray9368]

I honestly do think we've had a fairly big impact on this sport over the years, in and out of the arena. I realize how lucky I am to be able to do something I enjoy so much, for so long! I really do love this sport!

[@BotvacProductions469]

@@ray9368 exactly!

[@thorwaldjohanson2526]

Tombstone was my absolute favorite back then. Ray showed how strong and reliable spinners can be and it drew a crowd.

[@BotvacProductions469]

@@thorwaldjohanson2526 wdym by "back then"

[@thorwaldjohanson2526]

@@BotvacProductions469 there is just so many other super cool robots nowadays. Hard to have one absolute favorite. The engineering on battlebots is on a whole different level today. And the power density has gone through the roof. Tombstone does not stand out as much anymore. Still love him though :)

[@scp-zilla5303]

All of Ray’s opponents are gonna be difficult. From Valkyrie’s weapon reach advantage, to Orbitron’s A.I. system, to Hypershock’s everything. Best support to you, Ray, you’ve got a big hill to climb, but Tombstone is always up for a challenge.

[@mikedski9698]

Tombstone The King Of Kinetic Energy Is The Reason I Always Watched BATTLEBOTS.

[@econecoff1725]

🧲 Also the King of Magnetic Energy. I confess I jumped when the outer part went _Ziiing_ up the center.

[@Fightn17]

Tombstone is the reason i watch battlebots!!!!!! GO RAY!

[@econecoff1725]

Yip! The competition gets ever more powerful and precise, but even when Tombstone loses it goes out in fury-filled blaze.

[@RoboJRR]

WOW!! The TV show does not do justice to how powerful these motors are nor how dangerous they can be repair or rebuild! Seeing that was eye opening! And when Ray mentioned using TWO relays to spread the load of amperage - Mind Blown...I had never heard of that before.

[@inthefade]

After watching the entire history of BB during the pandemic I finally watched some build videos and behind the scenes footage... The show really doesn't do a good job of conveying just how SCARY and dangerous these machines are! They should include footage of them ripping apart every day items just to demonstrate to the audience what people like Ray have built.

[@thorwaldjohanson2526]

Yeah it's crazy, some of the modern robots have the power of a car engine, all just being put into a heavy spinning weapon. People forget that these robots weigh as much as an overweight man. And they get tossed 15 ft in the air at times with a single millisecond hit. The power is unreal.

[@RoboJRR]

@@inthefade I agree!

[@produKtNZ]

Hi Ray! - Can't wait to watch you at BB AGain soon! :D

[@AdamNRG316]

16:56 bloody hell that scared the shit out of me lol. Brilliant video Ray. Had no idea you modified the motors so much. Such an interesting watch.

[@BotvacProductions469]

lmao

[@elitesniper923]

Wouldn't be Tombstone without the BIG HOSS motor to power it. Can't wait to see this in action again!

[@siriusalpha4254]

I can’t believe I found THE Ray Billings from my childhood! I can’t wait to see how my favourite robot and its creator evolves!!! Subscribed without hesitation 🎉

[@toxicdragon323]

That's incredible. I wonder how much power that thing is packing. I'm glad that Tombstone is going to be back in action soon! Love the carnage it brings!

[@TheInvertedFollicle507]

Around 20 - 25 horsepower at about 1100 amps at peak load on the ME708, I'm not sure about the others.

[@thomashp]

Thanks for making these videos! As a builder that has never made more than a 1lb bot, you make building the bigger bots seem not so difficult. I hope to one day see you in the arena.

[@schuylerpryne5]

Thanks for sharing all this neat info. As a former oil and gas tech, its neat to see failure modes in unusual environments. Things pushed way further than engineers designed them for and the goofs like us that make them work for our extereme environments.

[@ray9368]

My "drilling in the field" job was water wells, but I understand your point completely! Finding new an unique ways to make things work in the field is an entirely different type of engineering. But I learned two super important things with that job. 1) No matter how bad something gets broken, it can always be fixed. And 2) Whatever odd, sketchy, insane thing you have to do to get it working again, DO THAT! The only wrong answer is "I couldn't make it work"

[@davida1hiwaaynet]

Thanks Ray. I really appreciate your shop time videos. Fascinating seeing how you apply the lessons learned in the arena. That is a heck of a motor..... I have seen just what it can do so I am in no way surprised at the size!

[@JohnWick-zl5oc]

good luck TOmbstone is the most awesome robot of all time, legendary , its great to see it back!

[@JamesBaillie-c6q]

Can't wait to see Tombstone in combat again especially with the robots that you are fighting. can't wait!!!

[@LightningGTM]

I've heard several builders at smaller weight classes talk about "battle-hardening" their motors. It makes sense that the same thing has to be done at the heavyweight level, but I don't think I've ever realized just how arduous of a process it is. Can't wait to see Tombstone fight again!

[@WiscomptonBoys]

Nice tip on assembly with how dangerous the magnets can be. They make assembling smaller motors a hassle, but something at this scale is pretty intimidating with that big snap when the two join up!

[@danielwindler7404]

very interesting technical aspects that people wouldn't know about otherwise. cool.

[@k2_robotics]

Love this video mixing explanations, showing "metal" and short videos machining the real things! Good luck for this season! I understand the unhappy US people with this kinda weird season, but people overseas (I'm from Spain, Europe) will be able to watch a season finally on KZbin wich is a good thing for the Battlebots franquice I guess.

[@ruvimsemenyuk8224]

Best of luck Rey hope you win single match in spectacular fashion 🔥

[@salmanmorris4484]

I can watch you all day doing tombstone stuff

[@mattmcwilliams7080]

I have one of those on my zero x dirt bike from 2011. the brushes were bad when i got it but still rode it a few hundred miles before it wouldn't go anymore. ran on one brush for a while. and then replaced the brushes in an hour because i already had the part and was back on the trail. still one of the most efficient and reliable motors available.

[@MauriceTheLesser]

Cant wait for the inevitable carnage from tombstone in November!

[@jeff9228]

Always great videos, Ray! Thanks for providing such great information and entertainment!!!

[@mikedski9698]

Ray Billings, GO FOR IT!

[@kevinmatney2218]

Thanks for the vids!!!!

[@ansgar_odinson]

I'm jonesin bad. Its been way too long since I have seen heavyweight robot violence. I need my fix. Seriously though, I cant wait to see Tombstone back in the arena.

[@MatthewBowe]

I've got my tickets! DESTROY ORBITRON!

[@starry53]

That magnet assembly startled me. Thinking that if my fingers caught on it must be painful to get it off.

[@Guffy1990]

With magnets that size, it's super easy to get it off since your fingers will unlock a new ability to be in 2 places at once! 50% on your hand, 50% on the table.

[@ray9368]

It's actually a lot of draw. It's really one of those things where if you're careful it's perfectly safe, but you should exercise a lot of caution. Even much smaller motors can still be a handful.

[@nathantowe4148]

that motor sounds crazy just sitting on a bench!

[@Doctorbasss]

18:18 Pay attention to not blow your power supply when reducing the voltage with the motor connected to it! the motor BEMF with inertia is enough to burn the discharge circuit inside! This hapenned to me with my POWERTEN and XANTREX when running my PERM132. The role of the circuit is to discharge the output capacitor when you reduce the voltage with the dial.. but the resistor and mosfet circuit called CROW BAR circuit can blow easy!!! This can be repaired easy but the best way to avoid that is puting a diode in serie at the output of your power supply when running motor.

[@amermirza991]

Let's see this motor in Action..

[@whitdodge]

Love your work!

[@Pyroteknikid]

3:30 ....."Everybody started hitting me back" *rolls eyes*

[@celeron55]

Beautiful, just a big DC motor and big contactors. Electronics are for nerds!

[@Boomtendo4tw]

More POWER! AR AR AR!

[@echo__noar8676]

Cant wait! Tomb has been my favorite for years. Ready to see that hunk of a blade wack some other bots!

[@TitoRigatoni]

Hey Ray, do you have any concerns with overheating the motor after eliminating the cooling slots? Or is it not running long enough in a fight for that to matter?

[@ray9368]

Yeah the duty cycle for combat is just not that long, and one advantage of the single high mass motor (rather than multiple smaller motors in tandem) is it takes a long time to heat it up. Even after a hard match, spinning for the whole 3 minutes, it's usually only slightly warm.

[@DavidSinanan]

@@ray9368 another thing you've got going for you is that you've significantly increased the thermal mass adding all that material to beef up the structure. So it will also take longer to reach critical thermal mass. Which works well with the strategy of 3 minute matches, I suspect.

[@JKSSubstandard]

"huh. never had that problem before" is the rallying cry of engineering. You know you fixed the previous failure mode properly when you find a new failure mode

[@ray9368]

Yeah, you're right. Part of the fun of this sport is working your way around the weird things we routinely break!

[@inthefade]

This is the refrain of every technician and engineer. I come from audio engineering and it is the same story even in that industry.

[@cheese.161]

Yes! Tomstone will finally not just burn to the ground when any robot hits it

[@BotvacProductions469]

dont say that! tombstone survived for a while at least :(

[@cheese.161]

@@BotvacProductions469 it did burn and lose a lot

[@BotvacProductions469]

@@cheese.161 he wont win EVERY SINGLE TIME

[@gigacu2023]

Esta temporada estara Genial! (Y)

[@petercarbin2077]

By reinforcing the top of the motor now you created a new weak point on the bottom The force just went to the next point

[@walletracer9882]

16:57 Yep, that's terrifying.

[@amadensor]

Everytime you make the failure point stronger, you find a new failure point.

[@MattyS02]

Love the videos and the info Ray, but the mic you're using to record the audio is clipping its ass off. If you pull the input gain down by 5-10dB it'll be clearer when recording and easier to listen to. If you need more volume just bump up the output when editing. Keep up the good work, look forward to the next round of BB!

[@ray9368]

I plan on getting some better audio equipment. These were cheapies, and they have been just sort of crappy. So yeah, I agree we need to address this.

[@BotvacProductions469]

16:57 AAAHHHH! THAT SCARED ME

[@ryo7625]

This engine is very interesting, I'm just wondering now: if you're aware of the engine being able to burn out itself, why do you still remove the Fan and why don't you give it a few air-holes so it stops overheating? Anyways I can't wait to see Tombstone in action, and to finally be able to actually watch that. (here in Germany we are quite cut off from Battlebots since we can't sub to Discovery US)

[@xSixtus]

Den Gedanken mit der Belüftung des Gehäuses hatte ich auch... Vielleicht sieht der alte Motor auch so verbannt aus, weil er keine Luft bekommen hat. Das man kein Battlebots sehen kann nervt mich auch sehr.

[@ryo7625]

@@xSixtus was heißt verbrannt, tatsächlich werden die Windungen häufig mit dunklem Kunststoff isoliert bei Elektromotoren

[@ray9368]

The motor was damaged from the batteries in the robot catching on fire. It wasn't from internal heat, but rather external with the whole robot engulfed in flames. Honestly air holes simply would have let more of that heat in! In a normal match, even spinning hard for the full 3 minutes, the motors don't get excessively hot.

[@ryo7625]

@@ray9368 I see, that actually makes sense. Thx for the clarification ^^

[@xSixtus]

@@ryo7625 hat sich das doch geklärt!

[@Doctorbasss]

Did you tried to adjust the timing with the brush? the trick is to run the motor and adjust the timing to have the minimum current by clocking the brush mount assembly relative to the motor housing. This will affect the KV and efficiency.

[@steveyoutube1709]

Great video!! Drill ventilation holes in new billet cover for cooling? I’ve never had luck with relays in parallel, probably because 1 connects before the other welding/burning the contacts

[@ray9368]

Yeah using two in parallel, one is always going to close sooner than the other. My original thought was to split out the brushes (there are 8 brushes, so 4 pairs) and if I did that each would see half the load discretely. But looking over the brush setup it's not quite as simple as just saying "I'll do that!". Some of it depends on time, since this event is going to sneak up on me quickly. I may put one together without splitting the brushes and simply do some testing and see how it holds up.

[@ConstantlyDamaged]

Do you harden the magnets at all? I've seen other builders epoxy the magnets in their motors to reinforce them against impact.

[@ray9368]

That's a really common failure on smaller motors, and I do that routinely for smaller weight class robots. But I've never had that be a failure in these, even with hundreds of combat matches. For now, it ain't broke so I'm not gonna fix it :)

[@BotvacProductions469]

@@ray9368 ah yes, bringing up a nice quote :)

[@randomsnow6510]

im pretty sure brushless motors have superiror power to weight ratios over brushed ones even when including esc mass, remember some extra mass is gained due to the high effeciency reducing the amount of batteries required to deliver the same power

[@ray9368]

Yes and no. In general, you are correct that the power to weight ratio is better, and usually they have higher efficiency. But much of that comes from SOOOO many poorly built brushed motors on the market. A well engineered brushed motor isn't too far off from a brushless setup. We may eventually redesign around a brushless setup for Tombstone, but for now I have these so I'll continue to use them. It's not like I am underpowered!

[@elitesniper923]

But with brushless means speed controllers and more stuff to worry about breaking. Looking at the other big horizontals like Triton or hijynx. Their spin up speed and power has nothing on Tombstone!

[@randomsnow6510]

@@ray9368 i suspected something like that, i thought the main reason you wernt using brushless motors was a lack of exsperience with brushless motors in tombstone and favouring reliability of the current configuration. tombstone doesent seem to be a design that would benefit that much from the weight savings of brushless motors since its blade is fairly close to the maxium allowable weight (i think) and i think its fairly close to the tip speed limit so extra power is redundant, its also not like it needs thicker amour since you could just hit the wheels if you could hit the robots amour (except maybe toplate for sawblaze?) so its amour somewhat irrelevant while still being importantish. there are probably bigger fish to fry with the design then brushless motor setups.

[@randomsnow6510]

@@elitesniper923 i think its a bad idea to speculate on the qualities of motor technologies by comparing differant performances of combat robots on the tv show, there are scientific papers and datasheets on brushless and brushed motors and it has been accepted for while that interms of pure performance brushless technology is superior, this is mainly because mosfets are much more effcient turning on and off the coils than rotating brushes becauses brushes are limited by arcing. IIRC the major limitation for brushless motors is there permant magnets heating up via induction and losing there magnetism.

[@Fattoxthegreat]

How do you feel about Triton's endeavor into brushless weapon motors? something you'd ever consider or no?

[@randomsnow6510]

vast majority of combat robots use brushless motors for there weapons, tombstone is fairly unique in its refusal to adopt the probably superior motor technology

[@ray9368]

Certainly at some point we'll be looking at some changes there. I could probably reduce the over height of the chassis with a different motor setup, since currently the motor height is what's specifying the chassis height. But for this series, I'm just going to use the motors I already have, and they have plenty of power.

[@yeetpotato9959]

GO TOMBSTONE

[@deppresionmeal942]

Hey ray, would you be able to give me the stats of the old pancake etek you used to use? Like size, weight, max kilowatt output, manufacture's recommend voltage and current, and what you used to run it at? I am trying to gather information on the original etek motors, and there is one I know that existed, but I can't find it anywhere.

[@ray9368]

All of the ratings listed for this at the time, were VERY conservative. So the actual performance was much more, and it's not like I ever figured out a dyno for it to really get accurate measurements. They listed max voltage as 48, and max amps as 330 for 1 minute. I ran them up to 72v, and with a contactor rather than an amp limiting speed control, so around 2000 amps at spinup. Obviously that is a LOT of watts, but at spin up a lot of that was simply making heat rather than power. Right now with the newer version, I am planning on running it at 12s lipo, so ~50v fully charged. This seems to be a good spot between power and reliability.

[@deppresionmeal942]

​@@ray9368 hey, at least you aren't overvolting or overamping brushless. I assume it was the 9.5 kg etek? Because I only see that version floating around, but I strongly remember there was a slightly bigger and smaller version of the etek.

[@ray9368]

We routinely overvolt brushless motors :) Limiting factor is always the esc, so if you get one that has higher limits than what the motor is spec'd for, you can get more power and the cost of reliability.

[@dennisschofield2881]

Your motor modification has removed the cooling system from the motor. The slots in the stock housing along with the spinning armature provide that cooling. Unless you replace that system with something of equal or greater efficiency, overheating or fire will always be a possibility. Thanks for the video and I always root for Tombstone.

[@ray9368]

This has been answered a lot through the comments, but I get it, there are a lot of comments to go through. I guess I'll add a response to the main description and see if this helps. The matches are 3 minutes long. And even if the match is a hard one, and the weapon has to spin for the entire time, the motor does not get overly hot. The problem here was, the batteries caught on fire and the robot burned for about 20 minutes in the arena. And we lost everything internally. This had nothing to do with the lack of cooling openings on the motor itself.

[@crazyrat51]

The six (eight) mounting bolts... Switch to aircraft grade STUDS. ARP would be a good source. You can spacify what kind of material you need. Studs clamp with a "sandwich" clamp... Much stronger. Just a thought. Do you know someone capable of turning that aluminum piece on a CNC machine? Made out of billet aluminum? Love watching your robot work!

[@crazyrat51]

Also you may want to source those on/off/ relay switches from again an aircraft/HELICOPTER supply. Helicopters have unbelievable vibration, which you probably know. Probably more duable than marine stuff.

[@crazyrat51]

Studs will not pull the top threads up!

[@ray9368]

Studs are better when clamping force is what you are after. So studs instead of bolts on say bolting down a head on a block - way better. In my case it's just shear strength, so it really comes down to the quality of the material used. A grade 8 stud and a grade 8 bolt will have the same shear strength. But, I do have to agree it would make some of the installation work better. So it is worth a consideration going forward!

[@HL4EHalfLife]

Hey Ray, nice rebuild! Just wondering, is there a reason you did not add ventilation holes in the new motor top? I would suspect a motor like that would kick off a LOT of heat during combat with all it's starts and stops, It also just occurred to me that adding ventilation holes would reduce it's overall weight allowing you to use that weight elsewhere.

[@ray9368]

The duty cycle is just short enough that it really isn't an issue, as long as I don't catch the batteries on fire! Under a normal match, even a hard one spinning the whole time, they don't get too warm. And ventilation holes also mean small arena debris can get in there, and over the course of an event there is a LOT of that small debris.

[@BotvacProductions469]

@@ray9368 i think one time when kraken fought and lost half its drive, i think its because they didnt vacuum the frame out before the match

[@ray9368]

@@BotvacProductions469 The arena gets super cruddy as the event wears on. They'll sweep up the big stuff, but that small stuff goes everywhere!

[@BotvacProductions469]

@@ray9368 i remember when last rites fought whoops! even the dust on the arena floor was scared of last rites

[@malcolmmackenzie9202]

This is awesome to watch i have also been following a channel called alex's alchemy he has a ant weight battle bot called cheesecake and that is awesome to watch too highly recommended.

[@russellhltn1396]

I'm a bit surprised you didn't work out a mount to go around the middle of the motor, especially after giving you some handy screws to help secure it. Given the shock forces, I'd think a middle mount would be better than trying to hold it all from one end. Of course, you'd have to modify the frame to hold it that way.

[@ray9368]

This mount setup looks really solid, but that mount plate is made out of titanium which is really springy. So the plate can flex a little under high G loads, which helps everything survive under big hits. I think a more rigid mount holding the middle more securely would just start giving me issues in other spots. It's honestly a good thought, but when I tried something similar with the cast case I had all kind of issues.

[@deathrev0859]

How would adding air holes or slots affect your cooling and weight, or how bad would it affect the strength? Is there a happy medium to be had?

[@BotvacProductions469]

hi again ray. quick question. are you planning on making more weapon bars or at least remanufacturing newer versions of your current ones? just curious

[@ray9368]

I have some metal here to make a couple of new ones, but it may come down to timing. Unfortunately I have a lot of non-robot stuff going on too.

[@BotvacProductions469]

@@ray9368 thank you for the info :)

[@funnybones46]

Ray. I had seen a purple colored brimstone with nailguns, stink eye with a shark tail, and a rat themed blip. Do you know about this?

[@-STONECYPHER-]

Does (or has in the past) tombstone incorporate a viscous coupling or clutch in the weapon system to limit the shock loads coming back to the motor? I imagine you could incorporate either device without greatly effecting the ultimate kinetic energy delivery of the weapon bar. The viscous coupling idea would likely slow down the spool up time for the weapon slightly, but probably not a whole lot. Probably only be super noticeable from a dead standstill. A friction clutch could easily be designed to be locked 99% of the time and only slip under very high shock loads.

[@ray9368]

www.mcmaster.com/6524K424/ Pretty standard commercial torque limiter.

[@ikocheratcr]

How much current that motor pulls when spinning the blade, steady state?

[@derek8043]

I'm curious about the use of a torque converter or something similar to absorb some shock in the drive train.

[@ray9368]

www.mcmaster.com/6524K424/ Pretty standard commercial torque limiter.

[@HwSystems]

It is little perturbing to know you use a contactor. Now I understand why your batteries catch fire like that. I'm a newbie in robotics, but a brushless IPM might be a lot more reliable with a programmable controller that will allow to set the max phase amp. But I'm sure you have a reason. IPM Motors of that power will cost you an arm.

[@ray9368]

Like most things in life, it's not quite that simple. First off, the fires I've had are all pretty much physical damage to the batteries, not electrical. I do know I am pushing them really hard, so I'm not discounting the rough effect that is happening to them, but I've also won a few championships with this setup as well. But with that much energy being unleashed, if the weapon bar gets a hunk removed and the robot is out of balance, it will in fact shake itself to death. The motor and controller type will have no bearing on the issues then. Brushless motor setups do have a lot of advantages, and I am sure that some day we will probably switch things around. But there are a few advantages to the setup I am using too. First off, raw torque at 0 rpm is definitely better with a brushed motor of this size. Even sensored brushless takes a bit to get itself sorted and provide full power. The initial spinup on Tombstone is tough, since the weapon is so heavy, and I need to be at a dangerous tip speed almost instantly. There are some real speed demons among my opponents, and I need to be deadly fast. And secondly (and real important for this upcoming event) I already have these motors. It's kind of hard to convince sponsors to jump on a KZbin series, so competing for this event is 100% out of my pocket. So I'm not going to make any wholesale changes right now.

[@aaronmays5156]

I notice you deleted the cooling holes in your modified cover, could that have contributed to the overheating?

[@ray9368]

I just now added a synopsis in the video description outlining this. Check it out!

[@gilbertotrevisan6538]

I'm kinda concerned 'bout ventilation...How do you keep'em cooled? Freeze it with dry ice before the battle?

[@ray9368]

The video description kind of explains this point. The matches are short enough that overheating really isn’t an issue

[@Al3xceptional]

With the custom motor assembly, is cooling not an issue since the cooling holes and fan are removed?

[@ray9368]

The matches are only 3 minutes long, and *usually the motor is barely warm at the end.

[@IsaacSchultz-lz8jc]

I thought everyone was using brushless motors for weapons

[@theusaftechguy]

What voltage are you running on the weapon motor?

[@ray9368]

12s Lipo, so ~50v for this version.

[@robigarashi9423]

Maybe need vent holes to cool.

[@ray9368]

I just now added a synopsis in the video description outlining this. Check it out!

[@Hunter1998ice]

Why are you using brushed motors ray? Wouldn't brushless be a better option?

[@celeron55]

Going to cost an arm and a leg, and be less reliable with all the electronics that it requires

[@ray9368]

There may come a day when we redesign the weapon motor arrangement, but for now I think I have enough power and I *have* these motors here to use :)

[@neutronium9542]

Did you have any problems with the reduced airflow, since there aren't any vent holes in the new design?

[@ray9368]

The video description spells it out a bit. Through the short length of a match, it really doesn't cause issues.

[@neutronium9542]

@@ray9368 That totally makes sense. What's the weight difference between the original motor and the modified one? It looks like there's a lot more metal in the modified design.

[@Stonerman135]

The old top aluminum piece had holes that hot air can escape through while the one you made doesn't. Could that contribute to your overheating?

[@ray9368]

The motor overheated because the robot was on fire. Had nothing to do with internal heat buildup.

[@BotvacProductions469]

@@ray9368 the robot wasnt on fire, i think the speed controller was. just sayin...

[@ray9368]

@@BotvacProductions469 The batteries were on fire (which burn really hot) and the entire robot was in flames. If you're trying to say the metal wasn't burning well then yeah I guess that's true. But it wasn't speed controllers - they can't put out that kind of heat.

[@BotvacProductions469]

@@ray9368 i knew it was either the batteries or the speed controllers. maybe i was thinking of fusion

[@ray9368]

In that particular match, the robot was a flaming mess for ~20 minutes in the box before we got it outside to pull the covers and try to salvage what we could. The fact that everything got overheated is completely understandable.

[@CreativeEngineering_]

Forklift contactors, 😉

[@Guds777]

Why don´t they switch, put the magnets in the rotor and electrify the stator, make it brushless. By googling around they make E Tech motors brushless...

[@ray9368]

There just aren't any viable options for speed control that I would be happy with unfortunately. Eventually I may switch to a brushless setup, but for now I am going to use the motors I already have. This sport gets expensive!

[@amadensor]

Did the heat affect the magnetism in the ring at all?

[@ray9368]

I don't believe so. Seemed as strong as normal to me when pulling it apart and putting it back together.

[@amadensor]

@@ray9368 it looked like it jumped pretty hard.

[@BotvacProductions469]

hey ray, sorry about bummer6. i bet hes getting on your nerves

[@ray9368]

Nah we're good. The world would be really boring if everyone had the same opinions about everything!

[@BotvacProductions469]

@@ray9368 true. just dont want you to feel alone in this

[@BotvacProductions469]

one last thing (maybe lol) sorry if im making too many comments lol

[@danielhumphrey5231]

Is this after your hand has healed?

[@ray9368]

My hand is about as healed as it is going to get. I won't say everything is fine, because it's clearly not. But for the most part it doesn't limit me too much. I do tend to work a little slower now, so I'm not quite as productive. But I can still do pretty much anything I want to do.

[@fabrice9893]

Il n'y a plus de passage d'air pour le refroidissement dans votre nouveau moteur, il risque de surchauffer et griller

[@ray9368]

I just now added a synopsis in the video description outlining this. Check it out!

[@T3hJimmer]

I'm curious why you don't use a brushless motor?

[@Guffy1990]

Way more torque in a brushed motor. Brushed = torque, brushless = RPM.

[@ray9368]

It really is hard to beat a brushed motor for raw torque at 0 rpm. Even good sensored brushless setups still chug for a bit before they get going, and a brushed motor just pulls no matter the load. At some point we'll probably switch over, but for this upcoming series I'll keep using the motors I already have.

[@T3hJimmer]

@@ray9368 Makes sense, thanks for the reply!

[@TrebleWing]

can't you just weld the crack?

[@ray9368]

Welding cast aluminum just isn't really a good idea. You *can weld it, but it's significantly weaker than it was before repairs, and obviously it wasn't strong enough to begin with.

[@PyroBear1776]

Hey I look at it like this, why build something super complex and not be able to figure out how to take it apart or how it works. In combat robotics simpler’s better. 😂

[@inthefade]

That Marc Rober battlebot ripoff video was so pathetic, scripted, and lame. I love seeing the actual engineers actually building really scary war machines.

[@ray9368]

And that is one view of combat robotics, certainly something I try to do here on my channel. "Here is how I build what I build" basically. But the important thing to remember is the target audience for his videos isn't dedicated combat robot fans. I think the videos will do really will with his target audience, and my hope is some of them then move into being more dedicated fans of the sport.

[@bummer6]

Tombstone is the battlebots equivalent of the bully going around the beach kicking over other kids' sandcastles. Other contestants are innovating, trying out fun designs, making a spectacle for people to watch, making incredible works of art fight each other. Meanwhile the Tombstone team wants to win, and they want to do it with the least amount of effort possible. They figured out the most powerful weapon and just put it on a bland chassis with the least complexity possible. No frills, no fun, no creativity. I pray for the day BB bans these kinds of spinners so we can see some exciting fights again until someone inevitably figures out a new broken meta. In Robot Wars it was Chaos 2 with its' insane flipper, in BB it's Tombstone. Although at least Chaos 2 had the decency to look half-way decent while doing its' thing.

[@D3moknight]

You are projecting your own opinion onto the rest of the audience. I love seeing spinners turn each other into shrapnel. It's the most destructive type of robot so far, and the destruction is very entertaining to a lot of people.

[@randomsnow6510]

tombstone doesnt domminate BB anymore, i think the most succesfull current design is sawblaze but im not sure.

[@ray9368]

You're certainly welcome to your opinion, and even if you don't enjoy what we do I am still glad you are watching the show! Many people feel our contributions to the sport are fun and exciting, but you disagreeing is fine and doesn't bother me any. I can say we won't be banned though :)

[@DavidSinanan]

That's hardly a fair evaluation. There certainly is quite a lot of creativity in this design! To be able to deliver and take such high degree of damage isn't merely over-engineering things. And what you're calling a bland design really is kinda on theme with the name Tombstone...kinda looks like a one...which I 'thought' was the point, considering the name. It's great science in the calculations he's shown for kinetic energy transfer etc. This is an elegant robot! It's not like Depth Charge where it destroyed the arena. Ray maintains a fine balance between raw, devastating power AND control. He's an excellent driver, with a very, very well engineered robot. Sure, innovation like Oribtron and many others is very cool, but Ray's designs have not been static internally. It's not like he doesn't have competition. In his bot's class, he's lost enough fights to show he can be beaten. He fights within the rules, and is very effective at what he does.

[@bummer6]

@@DavidSinanan Yes, Tombstone has been defeated several times, but it's entirely random if it happens. There's very little skill involved since in most cases where Tombstone has lost it's because it self destructs. Also, the fact that it "looks like a tombstone" doesn't make it elegant. Just because I call my robot "cube" and it happens to look like a cube doesn't mean there's any artistry going on. Just because something isn't illegal (yet) doesn't mean it's good for the sport.