Perfecting an Omnidirectional Combat Robot - Part 2

After the partial success of Scale Mk 1, my beetleweight combat robot/battlebot, I aim to fix the faults and properly win some fights. This includes a new single piece chassis, custom drive gearboxes, and a truly devistating eggbeater weapon.
Scale is a Beetleweight combat robot which means it competes in a 1.36kg weight class here in australia. This video includes it's performance at the Adelaide Robot Havoc 6 event where the last version got 3rd place.
If combat robots interest you, there is probably a club nearby! Many are active on facebook.
Music:
- Intro: Riffs for Days from youtube audio library
- Slow Motion: Barber of Seville Overture

[@bami2]

There's just something special about slow motion footage with classical music playing in the background of lipos catching on fire.

[@razer259]

😂 I'm genuinely touched! Thank you so much for your support. It means a lot, mate. And yes, I also look forward to the day we meet in the arena again! 😄

[@SethMarcell]

Subbed, going to watch your stuff too, this is so neat!

[@stcredzero]

A big part of the problem of robot combat involves control. What if someone used sensors, a microcontroller and the capability of omni wheels to implement an opponent-centered polar coordinates steering system? The weapon would always point at the opponent, and maneuvers to sidestep and circle around to vulnerable parts would be very simple, even almost foolproof!

[@patrickmattin9609]

​@@stcredzeroThe problem you have there is finding sensors that are durable enough for the job (sensitive electronics mounted on the edges of the robot isn't great) and also detecting your opponent. I can think of a few ways to do this, but simple driver skill can accomplish a similar goal if you're talking small robots and spinners. Orbitron in Battlebots does this, but that's in a much higher weight class, where it's easier to armor the relatively small sensors. Chomp, both the original tank drive version and the massive walker, also did this to good effect to accurately fire a hammer (usually not a particularly effective weapon).

[@Arsonade]

That fight against hurt feelings was one of the best fights I've seen

[@iggypeters5564]

the test when revin up the motor really scared me. You have the engineering balls of steel

[@SethMarcell]

SO LOUD!

[@barlowanimations1517]

Seeing the connections between FRC and Battlebots is awesome! Nice job.

[@LR-qi9rj]

please do not build an omnni drive frc bot

[@owenlennon2668]

@@LR-qi9rj someone on our team did

[@averageviewer6286]

Nice shout out for This Old Tony. 👏

[@shooty803]

This is a really excellent build and video! I love how much you go into detail with all of your design and manufacturing, and it's super cool to see some of the variety in the Australian BW scene. The concept really looks super solid at this point, excited to see where the design will go from here.

[@Shovel________________]

i've always been a fan of drum spinners. the shorter ranges often means the driver has to be more aggressive, which leads to some really interesting matches. also, if the torque is high enough, it's possible to literally dance with drum spinners

[@AJB2K3]

Sounds like an Air raid siren spinning up.

[@kurage_medusa]

I find the idea of a robot that when flipped over can still drag itself around on the _air_ without even any kind of propeller structure quite formidable. It's like if you cut off someone's limbs but they still managed to approach you by pure b l o o d l u s t.

[@potatopowers4602]

Looks like a very well build robot Also loving the videos

[@atlastheprotogen4282]

Amazing bot and a scary weapon, I wish you luck in your future journeys.

[@luuksta1027]

Great videos and concept! I appreciate you elaborate your choses. I have been thinking about the advantage of an omni drive robot and feel that a custom controller would help a lot with utilising the orthodox axis of freedom. A space mouse controller comes to mind, allowing for full movement control with one hand, leaving the other for weapons and other auxiliary functions. Hope this helps, if not, its for the algorithm gods. Good luck with your projects!

[@BrokenLinkRobotics]

Solid suggestion, may look into that. Currently translation uses two axis of one stick and rotation is a single axis of another. The transmitter is OpenTX, if one can get a space mouse talking to it then it shouldn't be too hard to do the translation.

[@mirohradsky]

@@BrokenLinkRobotics You might be able to make a custom controller utilising 3-axis joystick for the movement.

[@ImeEssien]

Great job! Great video! So happy for you!

[@SethMarcell]

Very cool! Can't wait for the next vid

[@blinkey9962]

Looks like I'm your 1000th subscriber, congratulations and good luck with the future content, great little robot : )

[@BrokenLinkRobotics]

Cheers mate

[@monotari6054]

Holy shit when the weapon spins up I get scared over the internet D:

[@andrijafrlan]

Your videos are nicely done.

[@IsaacKuo]

Interesting changes from the original! Very tight compact design fitting all those components in like that.

[@hygri]

All such sensible intellectual nice good solid engineering and clear logical progression of design and implementation, then the damn weapon spins up and I fully crap myself. This contrast excites me.

[@user-cg3em4cw4f]

Very nice!

[@nolanmcleod2619]

Great bot man, a lil unlucky there but keep on keeping on!

[@overmatchrobotics]

great job!! you're an amazing engineer. plz come to january norwalk

[@BrokenLinkRobotics]

Would love to, but it's and expensive flight from Sydney to get there. Probably not anytime soon unfortunately.

[@TheTwistedStone]

I think its more about perfecting control of such motion and you did pretty well. What's with the wiggling when you make a full turn ?

[@BrokenLinkRobotics]

Unlike tank steer this drivetrain does not naturally self align, so its hard to avoid oversteer. It's the most effective motion as all wheels can drive to full power so hard to tune out as well. Working on it though

[@birdyanimates9091]

Love the vid. May I ask what weapon motor you used?

[@gtdgabriste1]

I am curious about motor and esc choices, too. Also, an entire video on those gearboxes would not hurt my feelings.

[@BrokenLinkRobotics]

@birdyanimates9091 Sunnysky X2212 2450kv with a 40A BLheli-S ESC. 4s battery system. Same motors on drive but 980kv.

[@John-xl5bx]

Seems like proper weight distribution is critical for these wheels. And it is a shame to waste weight budget on ballast. This suggests you should change the shape and distribution of the motors and batteries. I know - easy for me to say. However, I suspect there are some obvious tweaks available if you forego the pretty symmetry of the equilateral triangle and go isosceles. An angle coupler on your drives would buy you some flexibility. Again, talk is cheap. Congrats and good luck.

[@BrokenLinkRobotics]

True, could try and rearrange things. Even just moving the beater back a bit would help as currently it's cantilevering over the front wheels to subtract weight from the rear. Is isosceles at the moment though.

[@herressen1271]

hey I was wondering if a outwashing toothprofile (like on a drillbit) would be beneficial contributing to flipping the enemy robot sideways. I think having a robot landing on top of yours might not be beneficial? Pushing them aside while flipping.

[@godlugner5327]

I loved this event and Scale getting knocked out by pit was just perfect old school WWE writing to keep the two most entertaining bots from getting obliterated 😂😂 it's all about Co-opetition to keep making the match interesting

[@EliotHochberg]

What about a horizontal spinner, so you can attack in any direction?

[@denisloebner4882]

wow lots going on in such a small package. i wonder for such a drumspinner as yours would it be possible/worth it to put the weapon motor(s) + their battery inside the drum and attach the drive shafts to the pulley? that way youd add quite some ''free'' weight to your weapon.

[@Mysda_]

I don't think batteries likes shocks at all

[@mw4222]

Great video! Question: was the steel stock for the beater pre-hardened or did you heat treat it after machining?

[@BrokenLinkRobotics]

Not pre hardened, and no treatment after. The ductility helped machining as well as ensuring the weapon did not crack on impacts at the cost of tooth wear. I think I'm happy with the material, I estimate I'll get 3 or 4 events out of a single beater.

[@mw4222]

@@BrokenLinkRobotics Wow ok thx for the info. Positively surprised that raw 4140 can be viable.

[@BrokenLinkRobotics]

Some gouges from direct hits on harder weapons but otherwise it just hits plastic or aluminium most of the time. 4140 is about as strong as low grade AR's, just not as hard.

[@markgearing]

You mentioned the weapon motor overheating. Is it possible to attach (or machine) fan vanes onto the eggbeater to direct air to the motor?

[@BrokenLinkRobotics]

Could do, would need to machine out some of the beater to make air holes though. I have a feeling it wouldn't help much though, simply need a bigger motor!

[@abhishekpersad4127]

How do you do the mixing for the omni-drive? Are there receivers that can do it or did you use a programmable microcontroller?

[@BrokenLinkRobotics]

Will do a video about it eventually, just mixing in the OpenTX transmitter. No smarts in robot. One resolves each input component vectors to the drive motor vectors with some constant multiplier, end up with 8 terms. Simple trigonometry and I reckon there'd be a guide somewhere for the maths.

[@abhishekpersad4127]

@@BrokenLinkRobotics Thanks, looking forward to the video

[@abhishekpersad4127]

@BrokenLinkRobotics btw, good idea on doing a video on it. A lot of these build videos on yt are very mechanical centric, which def isnt a bad thing, but i think a lot of people (like myself) would appreciate a deeper dive into the electronics/software integration as well!

[@robotwarsluvr]

I recognise your friends robot from somewhere 😂

[@BrokenLinkRobotics]

Some guy I think his name was jason

[@robotwarsluvr]

@@BrokenLinkRobotics Must be must be

[@BrokenLinkRobotics]

My bad, johnson

[@gtdgabriste1]

More development videos please. and where can I invest in your "get a real microphone" fund?

[@Why-Not-Robotics]

Are you thinking of coming to the next MCR comp on the 22nd?

[@BrokenLinkRobotics]

I'm running an event in Sydney on the 29th so would clash a bit, as well as being a costly plane ticket. Will come up again sometime though.

[@SrBuhler]

How do you design your asymmetrical flywheels and make sure they are balanced?

[@BrokenLinkRobotics]

@SrBuhler most CAD softwares allow you to see the center off mass. I trial and error until it's balanced.

[@MxMe-su1ch]

Why not use a horizontal spinner? It would seem to be much more omnidirectional.

[@Shovel________________]

i think the omni drive just allows for much more aggressive tactics, which drum spinners are very good for. also i think its because horizontal spinners are a lot less easy to fit on a bot with such a shape

[@BrokenLinkRobotics]

Basically what shovel said. A horizontal spinner needs good robot stance to react hit forces which an Omni wheel drive is not good at, would get hit away on every engagement.

[@MxMe-su1ch]

@BrokenLinkRobotics That's why the hemisphere shape is used though. Pushing back on a circle isn't easy.

[@connordlange]

Any way with that 100 extra grams in the back you could find a way to invert the robot back?

[@BrokenLinkRobotics]

Possible, but I feel loosing strafe for better invertability is suboptimal

[@bikall1]

is this mr beans son ??

[@olikat9774]

are you the guy who would have an inflatable flamingo on your shoulder at frc regionals?

[@BrokenLinkRobotics]

Yeah that's me, surprised someone remembers

[@mr.2minutes161]

i really hate the sound of it, its like telling me to hurry up when im relaxing, its stressing me up for some reason

[@HarveyChen253]

Coool! any interest in collaboration?

[@BrokenLinkRobotics]

Depends on what, and with who

[@HarveyChen253]

thx for the reply. This is PCBWay reaching out and we are wonder if we can do some project together @@BrokenLinkRobotics

[@BrokenLinkRobotics]

Feel free to reach out at the email address under my channel page

[@RoboArc]

I just wish there was a league of battle bots whether we're it's very limitations. Guns and rockets if you want them. Nothing bigger than a 22lr tough. I also wanna see better arenas, ullet prof glass, concrete and steel plating, and building and stuff in the way to block fire and damage. Like i wanna see some real combat with more sophisticated robots and drone tech. The tech is available for some scary stuff, I want t see the scary stuff. I used to watch drone fights, th dry were cool. I make robots now as a hobby and In college for it. I really wanna see what max human engineering can do other than this. This was cool in 1998 ~ 2005. It's fkn 2023 and really it's all the same stuff made with new materials. I'm not an fan. Am a fan of the parts you made though. Those are slick. Also nice tools

[@AlejandroFernandezDaCosta]

It would be better if you invest your skills and resorces in robotics for something usefull and constructive not something destructive and useless