Control Bot... with a Giant Blade??? SUBTRACTION NHRL Sept. 2023 Recap

[@cornmaized]

I am so hyped about the concept of motors made for robot combat! i hope to see subtraction achieve much more success in the future!

[@Kinekitsu]

Always love the NHRL recaps- it was awesome meeting you in Sept., best of luck with Subtraction in the future! Also, a direct drive motor just for Robot Combat, what a great idea~!

[@JustCuzRobotics]

Thank you! Was great to meet you as well and I hope we meet again, maybe even in the arena.

[@jakeyost1006]

Heads up the audio was very poppy around the 3:40 minute mark when discussing battle hardening the motors

[@glowytheglowbug]

mhm thought my audio screwed up

[@JustCuzRobotics]

Oh shoot, didn't notice that when editing. I realized after recording some later sections in OBS that was hapenning and I thought it was an OBS issue, but I think it was actually my mic cable being not fully plugged in. Didn't know it affected the voice over that early in the video.

[@TheInvertedFollicle507]

Same here... 🤔 🤔 🤔 Thought my phone had gone haywire or something 😅😅

[@hadengibbons3539]

Two ideas for that huge blade on subtraction: 1. A friction "clutch" of sorts that uses a spring and a friction plate to imparr the force onto the blade. Remove those dowel pins and have it rotate freely on its shaft 2. Seperating the motor from the actual blade with a 1:1 gear. This would make it more likely to survive the uppercut of doom whilst spinning, since it would decouple it from the impact. To make this work, i would suggest using an internal clutch system from my first point instead of external. I would also have the blade shaft connect to the bottom and top sections of the frame, constraining and reinforcing it.

[@JustCuzRobotics]

I already solved this issue in Subtraction V2 using a set of rubber washers between the blade and motor screws to allow the blade to rotate a few degrees seperate from the motor. It's not really a clutch but jt worked wonders.

[@WorldofWoodrow]

You are giving so much food for thought. I'm building my first spinner over the coming months and this video has a lot of stuff I can work with and on for it.

[@JustCuzRobotics]

Great to hear! Good luck with the build.

[@jordhan1]

literally last night i watched your video on division, and i was like, "the video about subtraction is gonna come out soon im sure" and then here we are!

[@cadentroyer]

Hey! Great fighting you man, always good to see ya. Toward the end of our fight my motor vibrated off my gearbox, which is why I lost drive! Hyperdrive will be back, hope to fight the next version in the future! 🔥

[@JustCuzRobotics]

Ah that makes sense. Was wondering about that. But yeah always a pleasure to fight you!

[@MADMAN_2415]

Hyperdrive is a pretty strong robot down in Florida. I’ve commentated for it multiple times, and most people I talk to say it’s very hard to beat it when it’s at its prime.

[@BamTehBrent]

You may have the answer to this: at around 9:30 are those 3D printed tpu belts that Hyperdrive is using?

[@cadentroyer]

@@BamTehBrentHey! I’m the builder of Hyperdrive, yes they’re 3D printed belts! I do it to create belts with tooth profiles that would not otherwise exist at the thickness I want.

[@---..]

It should be practical to include a little bit of a spiral spring as part of the weapon shape to reduce shock transfer to the motor without adding any parts. Might lower the moment of inertia a little since it will need some extra material near the middle to make it work without weakening things but it could be worth it. A weapon shape like division uses, but with a bit of a spiral around the center might do it.

[@JustCuzRobotics]

Not a bad idea overall. My concern with this is that it would also make the weapon flex up and down, which would make it really likely to chop my own wheels.

[@---..]

@@JustCuzRoboticsYes. Would probably work better on a bot with way more clearance, so not your current design. I can imagine some pretty sick designs built around that approach and that motor. Simple big springy angled horizontal spinner with lots wheel clearance (so smaller less effective drive). Probably couldn't drive or survive as well, but could smash good :)

[@JustCuzRobotics]

I did design a tombstone like horizontal spinner around the motor as well which I might build at some point to play with!

[@teambadengineeringchoices1368]

Nice. I think this surely shows promise but I would look into some sort of TPU spacer or hub for the weapon, especially to help with those vertical hits. albeit, you may be hitting yourself a little more.

[@TheInvertedFollicle507]

It's interesting a direct/gear drive concept cos more of the recoil of your own weapon system is transferred back into itself. Anyway great and well made video 👌🙏🙏

[@zedf7244]

Looking forward to seeing Subtraction next year! I'm sure you'll have a bunch of improvements to it by then. :)

[@ghrey8282]

There is probably no good way to put a support bearing around the upper bell, but it was the first thing to cross my ancient mind. Unfortunately bearings are heavy and require consistent alignment and support, hard to do in a top plate, especially when it’s getting hit. Just my .02 for the day.

[@JustCuzRobotics]

This very first version of the 4935 motor didn't have a magnet's epoxy from factory. I haven't had any issues with magnets shattering since that change was made. The flange to shaft also makes a pretty big difference to the durability of the motor.

[@bldjln3158]

Wow that’s definitely a stress test! Direct drive in beetles will break any motor. I’m really impressed by how long this one stood up

[@JustCuzRobotics]

I'm hopeful the improved motor plus a bit of shock mounting will be a lot better

[@mr.b6034]

Still think you would be better to run a dead shaft style. This would probably be cheaper in manufacturing process as well. This would beef up the body of the motor with no bearings mounted in it... being able to run bigger bearings above the stator and inline with the weapon blade. This will also allow a bigger surface area to transfer the impact and reduced leavering action on the shaft to the bearings...

[@JustCuzRobotics]

Currently a dead shaft setup would require that the motor be made taller as both bearings would need to fit on the top of the motor somehow. It's something I may look into in the future, maybe as a different product line. The current design is locked in for the next 50 motors.

[@Term-0]

I think an axial flux motor might work really well for a combat robot, both for isolating the coils from shock and for maximizing the power output/weight ratio. It might also help to use some sort of plastic to cover the magnets instead of epoxy.

[@JustCuzRobotics]

I don't know of any companies that make axial flux motors this size. I asked a company that does custom axial flux stator motors and they said designing a custom motor would cost $80,000 upfront so... Not happenning lol.

[@smaqdaddy]

Running your weapon on a jackshaft with a friction or belt drive would be the shit! You could have the quick speed and torque, but none of the shock going into the motor.

[@JustCuzRobotics]

There isn't really any space for that in this robot with the current design, but belt drive is really common in other designs

[@Crosshair84]

12:00 Instead of having metal pins connecting the weapon to the motor, you could instead use pins made of some sort of rubber. That would seem to be the simple solution. Understandable that you started out trying metal pins for worst case scenario and to get the extra mass of the motor..

[@JustCuzRobotics]

I have a similar plan. If all I did was replace the dowel pins I am afraid the rubber pins wouldn't do anything since all the load would be on the screws instead. So my current idea is use shoulder bolts that stick up higher than the weapon, with a 10mm diameter of TPU rubber around them and no dowel pins. That way there is several millimeters of 'squishiness'.

[@Crosshair84]

@@JustCuzRobotics Oh woops, I misunderstood how the blade was secured initially. For some reason I thought it had a single central fastening point and the pins prevented it from spinning. Thank you for the correction.

[@hellothere899]

Is there a way to add a bearing at the bottom of the bell? Adds complexity but might add strength?

[@JustCuzRobotics]

I did consider that. Long story short it would have been really expensive and reduced the motor power by 20% or meant a taller motor. The tradeoffs didn't seem worth it.

[@IsaacSchultz-lz8jc]

Maybe after yo get the weapon motor working well you could maybe make some brushless drive motors kits.

[@forceofwillgaming8475]

Will the CAD for SSP on your website be updated to reflect the new chassis design so people can design with the new chassis in mind

[@JustCuzRobotics]

Already has been 😊

[@zhuofanzhang9974]

Question - for the design in this video, is it likely for weapon ESC to overheat? I'm wondering what's the risk, especially considering it's situated close to TPU with a lower melting point.

[@JustCuzRobotics]

The weapon ESC did not get very hot in my testing, usually electronics will die at like 120-160C but TPU won't get too soft below 200C.

[@thememedream96]

A lifter or flipper named multiplication or addition

[@Drawliphant]

Theres going to ge much fewer belts to chomp in the future!

[@kbidols]

I am quite curious about your opinion on overhead spinner. In this vert domination days, would you consider overhead spinner still being competitive in any weight class?

[@JustCuzRobotics]

Firstly not every robot I build is intended to be competitive, I like building a bot that's different and interesting. Second, overhead spinners have a number of advantages in particular. They can hit in more than one direction and more than one side of the bot so being perfectly accurate driving is much less of a priority. A giant horizontal spinner frequently will outreach a lot of verts as well meaning I'll probably hit supporting structure on either side of their weapon. The spinner is my top armor so there is basically nothing a hammer/hammersaw/other overhead attack weapon will do to Subtraction. And horizontal spinners can be a lot more nimble driving as there are much less gyroscopic forces to worry about Vs verts. Just to name a few.

[@kbidols]

Great reply. Thanks man.@@JustCuzRobotics

[@BenH14928]

Aye, is that a Count Forkula reference at 9:12

[@sushsidnd]

Wow checked the price for the preorder and it was half the price that I was expecting. Definitely a great value motor considering the benefits it provides against competition.

[@Aflacist]

are u allowed to hit them again when they aren't moving? Seems like extra dmg for no reason.

[@JustCuzRobotics]

Until a Tapout is called I assume the opponent wants to keep the fight going

[@offcourseboys770]

Do you have a video of how you make it?

[@JustCuzRobotics]

I went over the design at the end of this video. But I don't really have a build video - those have generally performed really poorly for me on KZbin.

[@WartycoonDuos]

ngl i thought u where gonna tap when ur weapon died

[@lawlwut22]

So what I'm hearing is that putting one of these motors into an antweight would be ridiculous? Hmmmm.....

[@JustCuzRobotics]

If you can make weight for a 200+ gram weapon motor in a 454 gram robot that would be insanity

[@NeonDeion109]

Any Fingertech blade should work right?

[@JustCuzRobotics]

For what, with the 4935? Definitely not. You need a blade design for the mounting pattern on this motor.

[@NeonDeion109]

@@JustCuzRobotics yeah I thought they had a mount that fit most motors used in beetleweights. Ig I didn't quite notice the size difference. I was thinking more so the larger licensed blades they carry.

[@JustCuzRobotics]

The fingertech blade mount is meant for antweight motors for their Viper kit with max 6mm or 1/4" shaft. The 4935 motor has an 8mm shaft and is for beetles. It would also be far less secure to use their blade mount Vs four M5 bolts on this motor.

[@NeonDeion109]

@@JustCuzRobotics Any crazy ideas to give us an asymm blade or Bloodsport replicas?

[@JustCuzRobotics]

Possibly, I'll likely at least provide designs that can be sent to 3rd party waterjet or laser cutting places.

[@BamTehBrent]

Does Hyperdrive have 3D printed tpu belts???

[@JustCuzRobotics]

For this event it indeed used 3d printed belts. Not sure I would recommend that generally but it worked for him.

[@BamTehBrent]

​@@JustCuzRobotics my thoughts as well. Interesting. Thank you.

[@andrewpetrov7646]

i hate to be that guy but my ears form 3:48 to 4:15 somthing with the sound got mesed up or my headphones are deseving me

[@JustCuzRobotics]

Yeah sorry about that, my microphone decided to have a seizure due to a loose connection and I didn't realize that was hapenning til way later in the edit. Thought I had re-recorded everything that was affected but apparently not.

[@subsnovideos-ur4cn]

Where did you get the motor from?

[@JustCuzRobotics]

I essentially designed this one from scratch with the help of a motor manufacturer to help decide on the key features and what was feasible. This is not a rebranded existing motor. It's fully custom built just for me!

[@subsnovideos-ur4cn]

@@JustCuzRobotics what's the name of the company?

[@JustCuzRobotics]

I'm not going to publicly disclose my suppliers. If you actually need a specific custom motor we can discuss this privately via the contact us form on my site.

[@subsnovideos-ur4cn]

@@JustCuzRobotics I just wanted to know because I was curious on how people like you got custom motors and gearboxes made. I'm not going to waste your time going through all that knowing I'm not going to be buying anything. I don't have the money to buy several hundred motors (taking a hard guess there is a minimum buy order) and I wouldn't know what to do with all of them. If I ever wanted something custom made though, I'll contact you.

[@OmeletUSAF]