Appreciate the shoutouts, but definitely swap every time you said my name with "Team Seems Reasonable", if it was only me working on the concept it wouldn't have made it as far as it has 🙂 Math wise you have to remember that anytime you take something at one speed (in this case the opponent at 0m/s sitting still) and instantaneously ask it to be a different speed (whatever your flywheel is spinning at), your force number goes to infinity, which will either slip your clutch, or break something else in between. This is F=MA at work essentially, and also why vertical spinners rip and tear into opponents, the forces get so high material is yielded and getting hot, and then maybe depending how the bot being hit is constructed it goes flying upwards. Steps to making a flywheel flipper, 1. spin up a thing 2. punch yourself real hard 3. redirect that punch smoothly into the opponent so none of your stuff dies
@@Aren-Hill this explains the overcomplicated elastic "clutch?" On blip Transferring the kinetic energy from the flywheel to the target without breaking yourself must be hard That said what explains why blip does not have a low to the ground flip tip? It aways struggled to completelly get under the opponent to flip
@@MrPinguinzz Nothing in the Blip system is implemented to be functionally "elastic", the clutch is a "Cone Clutch" which fell out of favor awhile ago in cars because they tended to lock up too quickly, and the Dyneema bundle actually only stretches ~5% before the material starts failing. So the system functions by being fully modeled through range of motion expecting a max 250lb load on the end of the flipper when "fire" is pressed. Flipper tip wise it's a multi-faceted decision to put it where it is, (robot durability you have to survive to win, putting rev1 of a literally invented for this robot thing in a fight, S5 tantrum was great at wearing opponents as hats, etc). The core issue for S7 was the gyro being too much to drive well with when the flywheel was spun-up, so if I did drive well and get under someone it wasn't spinning fast enough to really flip. Now back to focusing on Seth bashing his head into the flywheel flipper wall
I love this design, and I love how simple you are endeavoring to make it. That is something I think we need to keep training ourselves on, because for some reason, it feels more natural to add parts than to take them away, but adding more parts to a combat robot is often just adding failure points.
@@JustCuzRobotics - I have also attempted to design (in my head) some kind of super fast clutch mechanism for a similar purpose, but it's real tough. Hopefully someone will crack the code, and you've got a pretty good head start!
I'm very interested in a dyneema twisting cord concept on a budget. I think Aren Hill figured out a huge issue with clutch systems : speed ramping. Instantly trying to apply a fast force is working against inertia a lot. His concept allows for a slow but powerful movement at the start, that ramps up in speed while reducing in torque, it's very optimal. And it makes the clutch engage fully before the movement really starts.
Yeah. I had a whole segment about that I cut out to prevent this video from being 45 minutes long. Twisted cord actuators are pretty sweet for making fast spinning motion into linear motion with a smooth power curve, but you need a way to engage the spinning flywheel on command with a stationery shaft and a way to turn the cord shrink motion into a flipping motion as well. You also need to unwind the bundle somehow before another flip. So this adds quite a few additional mechanical elements I was hoping to avoid.
35 years ago I made a $3000 squirt gun that could squirt 40 gallons per minute at the victim 80 feet away. My time and labor is not included. Designing, testing and making this human powered water cannon was quite the project. I won the next water fight! The opponent’s biggest problem was breathing. I really enjoy watching engineers design and build combat robots; and redesigning and rebuilding their perfect combat robot.🤪
Kinda interesting how Shrapnel Mine turned into a beetle weight Tantrum. Tantrum also started as a flipper and turned into a punching vertical spinner.
You know, I didn't actually think about the fact Tantrum started as a spring flipper until you mentioning it, that is funny. Tho really Shrapnel Mine was a completely unique setup in V1, sorta like a mashup of P1 and Sawblaze. I think a spring powered flipper would be a lot easier to engineer into a 3lb robot than a flywheel system, but it would be difficult to store enough energy for a ceiling shot. Certainly should be doable though.
@@JustCuzRobotics Maybe if you ever revisit the idea of making a beetle weight flipper, you could try to see if you could get a spring to store enough power to do celling shots at that small scale.
If you want to allow for rotational misalignment, maybe you could use a segment of a sphere? Although using a fast actuator and a dog clutch would be ten thousand times better
I wonder if something like an impact wrench mechanism would work better than a clutch at this scale. Shove the hammer mechanism into the anvil via servo to engage. Assuming the servo moves fast enough the engagement should be complete and instant. Force applied wouldn't be relying on the force of the servo at all. Though making a sturdy hammer and anvil setup in a reasonable weight is probably tough. Maybe titanium would be up to the task
Machining titanium sucks... I did look into impact wrench mechanisms but they aren't designed to deliver quite this much energy and they are much less weight optimized than I would like
Have you considered something more akin to an impact driver? Assuming the issue with your earlier iteration shown at 10:32 was that the teeth would not have enough time to mesh, you could mitigate that problem by having only 1-2 large teeth with plenty of space between them to allow them to engage at speed.
I suspect some bi-stable setup, like an over center mechanism, could be used to slam the clutch closed much quicker. Such approaches work great at small scales due to low part counts (thats how flees jump so high, and light switches don't get stuck in the middle for example). There are plenty of examples of 3d printed bi-stable mechanisms you could base one on as well.
The automation applications I’ve seen for small grabby clutches all used some sort of integrated coaxial, that is on the axis of rotation, high speed linear actuator, either pneumatic or electromagnetic. Many of these devices are not user serviceable. It is an interesting puzzle that I have been working on as well, but for a hammer….
There is a 30lb flywheel flipper called Magneato that uses a magnetic clutch but all the ones I found online are expensive and way too big for a 3lb robot. It is a great solution though at bigger scales.
@@JustCuzRobotics the smaller the clutch, actuator unit the higher the cost seems to be. I’ve seen small enough units,but the specks fell short. I’m currently looking at a multi plate break assembly. It should work, read as just possibly could. The failure rate may, by may I mean most likely, prove prohibitive. When you have a high torque requirement, and a very low maximum weight, you may have a problem. Edit: I just had the crazy thought that maybe some sort of motor break, capturing the reaction torque….. Hmmmmm
Do you happen to know if any photos or videos of that exist? The existence of the Jack Reacher TV series makes searching for the robot impossible now lol.
Might you be thinking of threecoil? That was a Mantisweight. Zac has been a huge inspiration for my flywheel flipper building adventures; the goat of all time.
Would an electromagnetic clutch work? They're used in automotive applications to engage belt driven accessories like fans or AC compressors. It seems like they could engage quicker for better energy transfer. There are some industrial units that are small enough for your application on the usual Chinese sites.
Maybe the axle (both for arm and flywheel) could have screw thread on part of it. The flywheel also has internal threads on it. The motor (separate from the flywheel) would spin the axle and the flywheel. The motor would then turn off and back current and magnetic drag would slow it down (could even use more advanced motor braking if your escs are capable of that). The flywheel would then quickly screw down the axle and press into the clutch disk with extreme force, transfering a large amount of energy. By using the motor, it will screw the flywheel back to its resting position and out of the clutch cone. This design might have several advantages: It only requires one motor, this can be direct drive to the axle. It has a high amount and perfectly even force pushing the flywheel into the clutch cone, roughly proportional to the amount of energy in the flywheel. The assembly would likely be rather reliable. Disadvantages: the kinetic energy of the motor rotor cannot be used. A hubmotor in the flywheel cant be used.
Not sure how I would ensure that the thread starts line up but that's an interesting idea. It would definitely require some precise metal parts that I can't make myself tho.
@kevinrabie7770 not necessarily, if the whole setup is rigid then the threads that are unthreading from the hubmotor are moving towards the stationery threads attached to the arm and they are also spinning at like 17000rpm. They would possibly get misaligned by up to half a thread and damaged by the high speed
@kevinrabie7770 While you're pushing your gears together to self-align you're also putting the edges of the teeth under tremendous stresses/impacts. If I understand the physics correctly, it becomes a balancing act between making the threads very fine, which means they're easier to catch but much more fragile, and making them too thick, which means they're less likely to shear straight off but there are fewer windows for mating the two gears. Ideally I think you'd want a gear with "infinite" teeth, so that you could stick the two together whenever and they'd still catch... which is essentially what Seth did by using surface roughness and friction.
@@fayvis I agree with the "infinite teeth" being the best solution, but you will always be fighting slippage that way. I don't agree that fine threads are easier to catch though. Course threads (fewer TPI) allow the teeth to engage more quickly and "catch". They shouldn't really be under that much stress since they should catch in one or two turns and you shouldn't need to push them that hard since once they bite they will naturally engage and pull it in the rest of the way. Deeper grooves/thicker threads also reduce the chance of cross threading and provides a stronger hold/bite, and like you said are less likely to shear. If you have course enough threads to not shear, you will have zero slippage and thus transfer near 100% of your flywheel force to the lifter near instantly. Now what the TPI and material of these threads will need to be will probably take trial and error or math that I'm not capable of .
Pretty Fly, another beetle flywheel flipper, did actually compete already, though its flywheel mechanism is very very different. Regardless, flywheel flipping is quite rareified air.
I just thought, instead of plastic on brass, using a properly designed friction surface might do the trick. Something like a brake pad for a bicycle disk brake should be small and light enough for the build. I'm not sure how pads designed for aluminium would do with brass, but even if pads get contaminated and only work for a couple fights, they are inexpensive off the shelf parts.
would using two rubber/tpu disks pressed against each other be a solution to your clutch issue? if the clutch is grippy and soft at the same time then it should engage more and more as they are pressed into each other as well as deforming to fix the misalignment issue?
If you managed to improve the Flywheel Flipper system, you might have created a decent Flipper bot to compete against Moonshot. I can't wait to see the NEW and IMPROVED Shrapnel Mine.
I wonder if a horizontal flywheel with a cam might work, it would at least get rid of most of the relevant gyro forces have a rail on the arm that slides a bearing over the cam slope when you want to flip
Did you at any point examine a shoe brake or other radially expanding device for the flywheel clutch? It seems at first glance like it may address some of the misalignment issues and provide better instantaneous contact surface, so I'd love to hear your thought process if you considered it!
you could try doing a cast urethane tapered wheel with a machined brass hub as the flywheel, then you get the grip of something like a banebots wheel with the added mass of a brass flywheel
Design a centrifugal clutch similar to chain saw clutch but run it in reverse so it locks instantly when certain rpm is reached. To engage the clutch you simply throttle up from 50% to 100%. Less moving parts compared to servo actuated flippers.
Have you consider adding some shallow teeth to the face of the flywheel and adding some recesses to the cup for the teeth to catch and rest into? Also instead the push configuration you have currently there, maybe have a slide-push so you can center align the servo. With a triangular wedge against the servo to engage the pushing mechanism of the motor in the center instead of the side.
@@JustCuzRobotics you could make them fully engage by geometry once they come in contact and translate the energy only after full engagement. This way, you could push it in just a bit, it will engage and pull the two parts together, once they are fully locked the energy will be transferred. If the backside of the teeth is also angled but in the other direction, you could even disengage by running your motor in reverse. As a result you wouldn't need a permanent connection between the "pusher" which pushes in for engagement and the part itself. This is beneficial since otherwise it would have to be pulled in once the first contact is made as well. Not sure if there is a way to show you a simple cad model of the idea and if its clear what I mean :D
Or in simpler terms, first engage a screw like component, once it's fully screwed in, you have lots of engagement and since it can't go further in, it will transfer all the energy
I would really like to see a tpu female clutch piece for this. Would you be open to share the failed trial cad files for the clutch? I've got some spare lead I think I could form for weight inside of a tpu shell.
So, what if there was a round bar connecting the clutch and flywheel, flywheel spinning with the bar going through it, and then the clutch sliding over it, or whichever way, but then they would be aligned. Also, both of them could have semi solid connections so that alignment with robot would be sacrificed and alignment between clutch and flywheel would be gained. Also, why not a metal clutch? Metal to metal would be far better imo, becouse it wouldnt stretch and slip only until the two bodies had no choice but to fully contact
Converting rotational momentum into high impulse torque? Have you examined the mechanism of a hammer drill or an impact wrench? Granted, you are dealing with a lot of angular inertia with a long flipper arm when compared to a hammer drill bit or an impact socket.
Charles Guan had a beetle weight flywheel flipper called "Roll Cake" that saw action a few years back, and I thought that it was in turn based on a similar small robot design from the mid to early aughts, I believe, but I can't find any proof.
I saw his blog post on the design of the robot, but didn't know that it actually ever got into an arena. There wasn't a lot of detail on what he did though.
@@JustCuzRobotics it's a linkage based flipper, and the flywheel spins a cam to push one of the linkages when the "clutch" is engaged. The "clutch" is a planetary gear system, that has (I think) the motor and drum driving the sun gear, the cam connected to the planet carrier, and the ring free to spin. When he wants to engage the "clutch", he uses a servo to lock the ring gear, forcing the planet carrier to spin. I've only seen one video of it in a real fight, and it looks like there were drive issues. The test vids show that it works a bit better than your current version, but the ones I found definitely don't give the impression it's capable of roofing anyone.
Where can I find the video you referenced for Moon Shot? I'd love to learn more about that design as well. Great video as always, can't wait for part 2!
It can be dangerous since the dust is very hazardous. I wore an N95 mask and chased the bit with a vacuum for good measure. Some people submerge cf in a water batch to avoid airborne dust as well. I wouldn't necessarily recommend doing it but it can be done if you are safety conscious.
Would a dog clutch be a better choice? It would negate friction. Also, instead of a servo, it could be actuated by pneumatics like in H Hills's 150g pneumatic flipper
Problem with dog clutches is they rely on impact which is inherently inefficient. Parts want to bounce and while momentum is conserved when they collide, you lose a lot of kinetic energy because both parts end up moving slower at the end.
For the flywheel flipper could you run dog engagement like used in car gearboxes " transmissions" ? A servo or an actuator could push the flywheel into a dog engagement cog on the flipper arm like the current set up. I do love your builds. Tantrum and blip are one of my favourite bots I cant remember what wait " magneto " was but that was a flywheel flipper in a smaller weight class " probably spelt its name wrong "
Magneato is a 30lb but yeah seen it. Dogs or teeth probably wouldn't work well as my flywheel is spinning too fast, the teeth would grind down or skip past one another unless I could engage them super fast
@JustCuzRobotics would it be possible to increase the mass of the flywheel and spin it at a lower rpm? Dog gears in cars can shift between 7-11000 rpm with a millisecond ignition cut on the motor. Would you be able to use one of the magnetic short throw actuators that are like on/off to engagement? I'm no engineer or bot builder just a daydreamer haha
@JustCuzRobotics would a more dense material like tungsten or a tool steel make that transition easier? All so, could you have two smaller dimensionally flywheels counter rotating to hold mass/ k-energy and minimise gyro effects? Brain storming 😳
If you are trying to launch an opponent skyward, then your robot needs to be able to survive the downward reactive force. If you are smashing the opponent into the ceiling, then your robot will be smashed into the floor.
No, there aren't any shock absorbers, but the wheels are printed in TPU, so they are somewhat flexible and can take impact well. The floor is relatively flat, so having actual spring-loaded shocks is pretty unnecessary, and it just adds unnecessary complexity to a robot design. Having soft tires is good enough.
Could you replace the servo pushing the hubmotor directly into the servo being a rack and pinion with [half the teeth removed] and pulling the hubmotor away from the arm, tensioning or compressing springs and then once it rotates far enough, firing the motor into the flipping arm? Its funny because youd be taking a mechanism from a normal flipper and using it to fire a flywheel into a flipper with enough pretensioning, the springs could fire the flywheel into the arm real hard and fast.
Doing that relies on the servo supplying enough force to retract the spring so the spring wouldn't be able to press harder than the servo. It might possibly help with the alignment issue but this setup was already really big and heavy and needs a total rethink
@@JustCuzRobotics Thats fair, I was thinking having a gear reduction after the servo but yeah thats even more weight and complexity. I was mostly hoping to fix having to balance torque vs activation time of the servo
That introduces a ton more weight and complexity and requires a huge hole in the robot for the air to pass through. Not a very good solution most of the time at 3lb. It's been done before once or twice tho, recently Hal Rucker's 30lb not Chicken did this although I don't think it helped a ton
@@JustCuzRobotics Outboard motors have a clutch that slams together the clutch pieces not like a car with a clutch pad. I can’t explain exactly how it works in comments but I can recommend a video that explains it in detail.
Every linear actuator I've ever seen is unbelievably slow and extremely bulky and heavy. A flat disk clutch theoretically is much worse than a cone clutch of the same size but if I tried this all again I might go that route. I was limited by what I could install onto my existing Hub-motor which wasn't great for this application it turns out.
Carbon Fiber isn't exactly space age tech these days, it's actually sometimes cheaper than an equivalent size aluminum part. But does have super high strength to weight so it's use a ton in combat robots
![Division V4: Hubmotor Weapon & Counter Gyro Put to the Test! [NHRL January 2024 Event Recap]](/img/n.gif)
Appreciate the shoutouts, but definitely swap every time you said my name with "Team Seems Reasonable", if it was only me working on the concept it wouldn't have made it as far as it has 🙂
Math wise you have to remember that anytime you take something at one speed (in this case the opponent at 0m/s sitting still) and instantaneously ask it to be a different speed (whatever your flywheel is spinning at), your force number goes to infinity, which will either slip your clutch, or break something else in between. This is F=MA at work essentially, and also why vertical spinners rip and tear into opponents, the forces get so high material is yielded and getting hot, and then maybe depending how the bot being hit is constructed it goes flying upwards.
Steps to making a flywheel flipper, 1. spin up a thing 2. punch yourself real hard 3. redirect that punch smoothly into the opponent so none of your stuff dies
That makes a lot of sense, sorry for not crediting the whole team!
@@Aren-Hill this explains the overcomplicated elastic "clutch?" On blip
Transferring the kinetic energy from the flywheel to the target without breaking yourself must be hard
That said what explains why blip does not have a low to the ground flip tip? It aways struggled to completelly get under the opponent to flip
Omg! Aren Hill! I love watching you on battlebots!
@@MrPinguinzz Nothing in the Blip system is implemented to be functionally "elastic", the clutch is a "Cone Clutch" which fell out of favor awhile ago in cars because they tended to lock up too quickly, and the Dyneema bundle actually only stretches ~5% before the material starts failing. So the system functions by being fully modeled through range of motion expecting a max 250lb load on the end of the flipper when "fire" is pressed.
Flipper tip wise it's a multi-faceted decision to put it where it is, (robot durability you have to survive to win, putting rev1 of a literally invented for this robot thing in a fight, S5 tantrum was great at wearing opponents as hats, etc). The core issue for S7 was the gyro being too much to drive well with when the flywheel was spun-up, so if I did drive well and get under someone it wasn't spinning fast enough to really flip.
Now back to focusing on Seth bashing his head into the flywheel flipper wall
What if you could make the collision of your bot into the other bot act as the "punch" or add it's force to it?
Punching spinner? Flywheel flipper? Seems reasonable.
I love this design, and I love how simple you are endeavoring to make it. That is something I think we need to keep training ourselves on, because for some reason, it feels more natural to add parts than to take them away, but adding more parts to a combat robot is often just adding failure points.
Thank you! I just wish it actually worked lol. I will probably revisit a flipper someday tho.
@@JustCuzRobotics - I have also attempted to design (in my head) some kind of super fast clutch mechanism for a similar purpose, but it's real tough. Hopefully someone will crack the code, and you've got a pretty good head start!
I'm very interested in a dyneema twisting cord concept on a budget. I think Aren Hill figured out a huge issue with clutch systems : speed ramping. Instantly trying to apply a fast force is working against inertia a lot. His concept allows for a slow but powerful movement at the start, that ramps up in speed while reducing in torque, it's very optimal. And it makes the clutch engage fully before the movement really starts.
Yeah. I had a whole segment about that I cut out to prevent this video from being 45 minutes long. Twisted cord actuators are pretty sweet for making fast spinning motion into linear motion with a smooth power curve, but you need a way to engage the spinning flywheel on command with a stationery shaft and a way to turn the cord shrink motion into a flipping motion as well. You also need to unwind the bundle somehow before another flip. So this adds quite a few additional mechanical elements I was hoping to avoid.
35 years ago I made a $3000 squirt gun that could squirt 40 gallons per minute at the victim 80 feet away. My time and labor is not included. Designing, testing and making this human powered water cannon was quite the project. I won the next water fight! The opponent’s biggest problem was breathing.
I really enjoy watching engineers design and build combat robots; and redesigning and rebuilding their perfect combat robot.🤪
Kinda interesting how Shrapnel Mine turned into a beetle weight Tantrum.
Tantrum also started as a flipper and turned into a punching vertical spinner.
You know, I didn't actually think about the fact Tantrum started as a spring flipper until you mentioning it, that is funny. Tho really Shrapnel Mine was a completely unique setup in V1, sorta like a mashup of P1 and Sawblaze.
I think a spring powered flipper would be a lot easier to engineer into a 3lb robot than a flywheel system, but it would be difficult to store enough energy for a ceiling shot. Certainly should be doable though.
@@JustCuzRobotics Maybe if you ever revisit the idea of making a beetle weight flipper, you could try to see if you could get a spring to store enough power to do celling shots at that small scale.
If you want to allow for rotational misalignment, maybe you could use a segment of a sphere? Although using a fast actuator and a dog clutch would be ten thousand times better
I wonder if something like an impact wrench mechanism would work better than a clutch at this scale. Shove the hammer mechanism into the anvil via servo to engage. Assuming the servo moves fast enough the engagement should be complete and instant. Force applied wouldn't be relying on the force of the servo at all.
Though making a sturdy hammer and anvil setup in a reasonable weight is probably tough. Maybe titanium would be up to the task
Machining titanium sucks... I did look into impact wrench mechanisms but they aren't designed to deliver quite this much energy and they are much less weight optimized than I would like
Have you considered something more akin to an impact driver? Assuming the issue with your earlier iteration shown at 10:32 was that the teeth would not have enough time to mesh, you could mitigate that problem by having only 1-2 large teeth with plenty of space between them to allow them to engage at speed.
I suspect some bi-stable setup, like an over center mechanism, could be used to slam the clutch closed much quicker. Such approaches work great at small scales due to low part counts (thats how flees jump so high, and light switches don't get stuck in the middle for example). There are plenty of examples of 3d printed bi-stable mechanisms you could base one on as well.
Might be worth looking into but that solves just 1 of many problems
The intro was ridiculous in the best way!
Whyachi's Warrior Dragon was one of my favorite robots back in the day. Building a kinetic energy flipper is on the bucket list.
Warrior Dragon was pretty cool, love the idea of the flywheel also being a weapon.
Seth really said, “let me build a 3lb blip” “Nevermind, I’ll build a 3lb tantrum instead”
That was an amazing intro! It really did Shrapnel Mine justice, so please try out more stuff like that in the future
IM SORRY. SHRAPNEL MINE IS 3 YEARS OLD!!!!
no way time is zooming this fast
Intro was unusual. I enjoyed it.
The automation applications I’ve seen for small grabby clutches all used some sort of integrated coaxial, that is on the axis of rotation, high speed linear actuator, either pneumatic or electromagnetic. Many of these devices are not user serviceable. It is an interesting puzzle that I have been working on as well, but for a hammer….
There is a 30lb flywheel flipper called Magneato that uses a magnetic clutch but all the ones I found online are expensive and way too big for a 3lb robot. It is a great solution though at bigger scales.
@@JustCuzRobotics the smaller the clutch, actuator unit the higher the cost seems to be. I’ve seen small enough units,but the specks fell short. I’m currently looking at a multi plate break assembly. It should work, read as just possibly could. The failure rate may, by may I mean most likely, prove prohibitive. When you have a high torque requirement, and a very low maximum weight, you may have a problem.
Edit: I just had the crazy thought that maybe some sort of motor break, capturing the reaction torque…..
Hmmmmm
If this works out, flywheel hammers will be the new meta.
You had me at "once upon a time!"
I remember years ago Zac O'Donnell made a flywheel powered flipper beetle weight for Pennsylvania Bot Blast. It eventually evolved into Jack Reacher.
Do you happen to know if any photos or videos of that exist? The existence of the Jack Reacher TV series makes searching for the robot impossible now lol.
Might you be thinking of threecoil? That was a Mantisweight. Zac has been a huge inspiration for my flywheel flipper building adventures; the goat of all time.
@@JustCuzRobotics The channel robotdesigner has a detailed explanation of the flywheel setup on Jack Reacher.
He's made quite a few of them. Reclipso was the beetle, Threecoil was the mantis, then there was Jack Reacher and now I believe he has Magneto.
Would an electromagnetic clutch work? They're used in automotive applications to engage belt driven accessories like fans or AC compressors. It seems like they could engage quicker for better energy transfer.
There are some industrial units that are small enough for your application on the usual Chinese sites.
Maybe the axle (both for arm and flywheel) could have screw thread on part of it. The flywheel also has internal threads on it. The motor (separate from the flywheel) would spin the axle and the flywheel. The motor would then turn off and back current and magnetic drag would slow it down (could even use more advanced motor braking if your escs are capable of that). The flywheel would then quickly screw down the axle and press into the clutch disk with extreme force, transfering a large amount of energy. By using the motor, it will screw the flywheel back to its resting position and out of the clutch cone. This design might have several advantages: It only requires one motor, this can be direct drive to the axle. It has a high amount and perfectly even force pushing the flywheel into the clutch cone, roughly proportional to the amount of energy in the flywheel. The assembly would likely be rather reliable. Disadvantages: the kinetic energy of the motor rotor cannot be used. A hubmotor in the flywheel cant be used.
Not sure how I would ensure that the thread starts line up but that's an interesting idea. It would definitely require some precise metal parts that I can't make myself tho.
@@JustCuzRobotics Shouldn't the threads self align within one rotation?
@kevinrabie7770 not necessarily, if the whole setup is rigid then the threads that are unthreading from the hubmotor are moving towards the stationery threads attached to the arm and they are also spinning at like 17000rpm. They would possibly get misaligned by up to half a thread and damaged by the high speed
@kevinrabie7770 While you're pushing your gears together to self-align you're also putting the edges of the teeth under tremendous stresses/impacts. If I understand the physics correctly, it becomes a balancing act between making the threads very fine, which means they're easier to catch but much more fragile, and making them too thick, which means they're less likely to shear straight off but there are fewer windows for mating the two gears.
Ideally I think you'd want a gear with "infinite" teeth, so that you could stick the two together whenever and they'd still catch... which is essentially what Seth did by using surface roughness and friction.
@@fayvis I agree with the "infinite teeth" being the best solution, but you will always be fighting slippage that way. I don't agree that fine threads are easier to catch though. Course threads (fewer TPI) allow the teeth to engage more quickly and "catch". They shouldn't really be under that much stress since they should catch in one or two turns and you shouldn't need to push them that hard since once they bite they will naturally engage and pull it in the rest of the way. Deeper grooves/thicker threads also reduce the chance of cross threading and provides a stronger hold/bite, and like you said are less likely to shear. If you have course enough threads to not shear, you will have zero slippage and thus transfer near 100% of your flywheel force to the lifter near instantly. Now what the TPI and material of these threads will need to be will probably take trial and error or math that I'm not capable of .
Seth IS Aren, Shrapnel mine is tantrum and he just made a mini blip.
Heh I wish. Aren is an extremely talented engineer.
Pretty Fly, another beetle flywheel flipper, did actually compete already, though its flywheel mechanism is very very different. Regardless, flywheel flipping is quite rareified air.
Goated intro
Excellent
I just thought, instead of plastic on brass, using a properly designed friction surface might do the trick. Something like a brake pad for a bicycle disk brake should be small and light enough for the build. I'm not sure how pads designed for aluminium would do with brass, but even if pads get contaminated and only work for a couple fights, they are inexpensive off the shelf parts.
would using two rubber/tpu disks pressed against each other be a solution to your clutch issue? if the clutch is grippy and soft at the same time then it should engage more and more as they are pressed into each other as well as deforming to fix the misalignment issue?
If you managed to improve the Flywheel Flipper system, you might have created a decent Flipper bot to compete against Moonshot.
I can't wait to see the NEW and IMPROVED Shrapnel Mine.
I wonder if a horizontal flywheel with a cam might work, it would at least get rid of most of the relevant gyro forces
have a rail on the arm that slides a bearing over the cam slope when you want to flip
Did you at any point examine a shoe brake or other radially expanding device for the flywheel clutch? It seems at first glance like it may address some of the misalignment issues and provide better instantaneous contact surface, so I'd love to hear your thought process if you considered it!
Now i want a flywheel HAmmer/Axe bot
Shrapnel Mine my absolute beloved💙🧡💙🧡
you could try doing a cast urethane tapered wheel with a machined brass hub as the flywheel, then you get the grip of something like a banebots wheel with the added mass of a brass flywheel
it would also squish into the part, maximizing the surface area in contact with the flipper
Design a centrifugal clutch similar to chain saw clutch but run it in reverse so it locks instantly when certain rpm is reached. To engage the clutch you simply throttle up from 50% to 100%. Less moving parts compared to servo actuated flippers.
Centrifugal clutch is itself quite complex to make and has a lot of small parts inside.
Have you consider adding some shallow teeth to the face of the flywheel and adding some recesses to the cup for the teeth to catch and rest into? Also instead the push configuration you have currently there, maybe have a slide-push so you can center align the servo. With a triangular wedge against the servo to engage the pushing mechanism of the motor in the center instead of the side.
I am afraid any teeth would get eaten as the clutch isn't fully engaged at first. But maybe something to try if I ever revisit this in the future.
@@JustCuzRobotics you could make them fully engage by geometry once they come in contact and translate the energy only after full engagement.
This way, you could push it in just a bit, it will engage and pull the two parts together, once they are fully locked the energy will be transferred.
If the backside of the teeth is also angled but in the other direction, you could even disengage by running your motor in reverse.
As a result you wouldn't need a permanent connection between the "pusher" which pushes in for engagement and the part itself. This is beneficial since otherwise it would have to be pulled in once the first contact is made as well. Not sure if there is a way to show you a simple cad model of the idea and if its clear what I mean :D
Or in simpler terms, first engage a screw like component, once it's fully screwed in, you have lots of engagement and since it can't go further in, it will transfer all the energy
I would really like to see a tpu female clutch piece for this. Would you be open to share the failed trial cad files for the clutch? I've got some spare lead I think I could form for weight inside of a tpu shell.
I tried TPU and it failed just about the same as the CF Nylon did. I suppose I could share the cad
So, what if there was a round bar connecting the clutch and flywheel, flywheel spinning with the bar going through it, and then the clutch sliding over it, or whichever way, but then they would be aligned. Also, both of them could have semi solid connections so that alignment with robot would be sacrificed and alignment between clutch and flywheel would be gained. Also, why not a metal clutch? Metal to metal would be far better imo, becouse it wouldnt stretch and slip only until the two bodies had no choice but to fully contact
Why not metal to metal because it was already kind of too heavy as it was with plastic.
If only someone sells battlebots this small
I do actually! justcuzrobotics.com/products/ssp-robot-kit
i wonder if there is a premade clutch that would work, or maybe a interlocking gear system to shift
Nothing close to small and lightweight enough, unfortunately.
Converting rotational momentum into high impulse torque? Have you examined the mechanism of a hammer drill or an impact wrench? Granted, you are dealing with a lot of angular inertia with a long flipper arm when compared to a hammer drill bit or an impact socket.
I just read other comments. It seems that I am hardly the first to suggest this.
Charles Guan had a beetle weight flywheel flipper called "Roll Cake" that saw action a few years back, and I thought that it was in turn based on a similar small robot design from the mid to early aughts, I believe, but I can't find any proof.
I saw his blog post on the design of the robot, but didn't know that it actually ever got into an arena. There wasn't a lot of detail on what he did though.
@@JustCuzRobotics it's a linkage based flipper, and the flywheel spins a cam to push one of the linkages when the "clutch" is engaged. The "clutch" is a planetary gear system, that has (I think) the motor and drum driving the sun gear, the cam connected to the planet carrier, and the ring free to spin. When he wants to engage the "clutch", he uses a servo to lock the ring gear, forcing the planet carrier to spin.
I've only seen one video of it in a real fight, and it looks like there were drive issues. The test vids show that it works a bit better than your current version, but the ones I found definitely don't give the impression it's capable of roofing anyone.
Ah. Good to know about tho! Thanks for the info.
Where can I find the video you referenced for Moon Shot? I'd love to learn more about that design as well. Great video as always, can't wait for part 2!
th-cam.com/video/bzZufNCXaeE/w-d-xo.htmlsi=SKbtzutxLHDx_2Wr
@@JustCuzRobotics Thx!!
Do you have any tips for milling carbon fibre. My school has never done it before, and I want to be as safe/successful as possible.
Thanks in advance
It can be dangerous since the dust is very hazardous. I wore an N95 mask and chased the bit with a vacuum for good measure. Some people submerge cf in a water batch to avoid airborne dust as well. I wouldn't necessarily recommend doing it but it can be done if you are safety conscious.
Lmaoo I loved that intro
Would a dog clutch be a better choice? It would negate friction. Also, instead of a servo, it could be actuated by pneumatics like in H Hills's 150g pneumatic flipper
Problem with dog clutches is they rely on impact which is inherently inefficient. Parts want to bounce and while momentum is conserved when they collide, you lose a lot of kinetic energy because both parts end up moving slower at the end.
Dale's homemade robotics made a successful 12 pounder using a dog clutch system, so it's definitely possible. The robot was called T-boner.
Is there still hope with the flywheel flipper mech?
Idk. Maybe someday.
I've been thinking about this design for a while....would it be possible?! Thanks!!
Watch the video and learn from my mistakes.
For the flywheel flipper could you run dog engagement like used in car gearboxes " transmissions" ?
A servo or an actuator could push the flywheel into a dog engagement cog on the flipper arm like the current set up.
I do love your builds.
Tantrum and blip are one of my favourite bots
I cant remember what wait " magneto " was but that was a flywheel flipper in a smaller weight class " probably spelt its name wrong "
Update its name was " magneato " by robotdesigner on youtube
Magneato is a 30lb but yeah seen it. Dogs or teeth probably wouldn't work well as my flywheel is spinning too fast, the teeth would grind down or skip past one another unless I could engage them super fast
@JustCuzRobotics would it be possible to increase the mass of the flywheel and spin it at a lower rpm? Dog gears in cars can shift between 7-11000 rpm with a millisecond ignition cut on the motor.
Would you be able to use one of the magnetic short throw actuators that are like on/off to engagement?
I'm no engineer or bot builder just a daydreamer haha
It would be possible, but the flywheel being so large and massive is already one of the big problems with this design, in my opinion.
@JustCuzRobotics would a more dense material like tungsten or a tool steel make that transition easier?
All so, could you have two smaller dimensionally flywheels counter rotating to hold mass/ k-energy and minimise gyro effects?
Brain storming 😳
If you are trying to launch an opponent skyward, then your robot needs to be able to survive the downward reactive force. If you are smashing the opponent into the ceiling, then your robot will be smashed into the floor.
I know that, and that was always considered in the design
@@JustCuzRobotics Excellent. Do you robot's wheels have shock absorbers?
No, there aren't any shock absorbers, but the wheels are printed in TPU, so they are somewhat flexible and can take impact well. The floor is relatively flat, so having actual spring-loaded shocks is pretty unnecessary, and it just adds unnecessary complexity to a robot design. Having soft tires is good enough.
Could you replace the servo pushing the hubmotor directly into the servo being a rack and pinion with [half the teeth removed] and pulling the hubmotor away from the arm, tensioning or compressing springs and then once it rotates far enough, firing the motor into the flipping arm? Its funny because youd be taking a mechanism from a normal flipper and using it to fire a flywheel into a flipper with enough pretensioning, the springs could fire the flywheel into the arm real hard and fast.
Doing that relies on the servo supplying enough force to retract the spring so the spring wouldn't be able to press harder than the servo. It might possibly help with the alignment issue but this setup was already really big and heavy and needs a total rethink
@@JustCuzRobotics Thats fair, I was thinking having a gear reduction after the servo but yeah thats even more weight and complexity. I was mostly hoping to fix having to balance torque vs activation time of the servo
16:58 is that a ssp vert kit?
Its a weapon addon option I have been working on. Life kinda got in the way but I hope to get back to improving it soon
How did you design your bot what’s a good program to use
I use fusion 360. Recommend that or on-shape, both are free
And what would be a good filament dryer your help has been invaluable
There are a few good options out there. I like the Eibos cyclops
Will it be able to dry nylon
@Firstordertrooper yup!
mmm spreadsheets im here for em....
Hopefully you aren't alone!
So sad of a tale...but hope remains.
For more traction, you could use a ducted fan to suck the robot to the floor.
That introduces a ton more weight and complexity and requires a huge hole in the robot for the air to pass through. Not a very good solution most of the time at 3lb. It's been done before once or twice tho, recently Hal Rucker's 30lb not Chicken did this although I don't think it helped a ton
@@JustCuzRobotics You could use multiple small holes if you added a flexible underskirt! :)
Sort of like an anti-hovercraft!
Use a Clutch modeled after a Outboard motor.
How would that work?
@@JustCuzRobotics Outboard motors have a clutch that slams together the clutch pieces not like a car with a clutch pad. I can’t explain exactly how it works in comments but I can recommend a video that explains it in detail.
Why not just use a linear actuator, and have the 'clutch' be flat, a bit similar to a car transmission
Every linear actuator I've ever seen is unbelievably slow and extremely bulky and heavy. A flat disk clutch theoretically is much worse than a cone clutch of the same size but if I tried this all again I might go that route. I was limited by what I could install onto my existing Hub-motor which wasn't great for this application it turns out.
Should do dogs and not a friction disk.
I must ask , why use a flywheel and clutch design .Why not a flywheel\break disc with a break caliper design. Breaks are for pure raw stopping power.
Brake calipers this small don't really exist and that would have meant a lot more custom components. Plus actuating them still requires a large force
@@JustCuzRobotics Totally understand at this scale. I think you 100% correct. It would require a complete bispoke design.
There are some 1/10th / 1/8th scale Nitro RC cars with servo actuated Disc breaks if you're interested going down that route @@JustCuzRobotics
The robot weighs only 3 pounds? That explains the carbon fiber. Space-age materials.
Carbon Fiber isn't exactly space age tech these days, it's actually sometimes cheaper than an equivalent size aluminum part. But does have super high strength to weight so it's use a ton in combat robots
@@JustCuzRobotics Cheaper than aluminum? I am quite surprised by that. Interesting. Thanks.
The material itself is probably more expensive, but I can get it cut by CNC Madness for a lot cheaper than I can get aluminum laser cut.
Bilp
I am well aware... 7:42
You’ll get it next time 🥹😭💪