The Idea Dump

I've always started a thread like this on my team's previous (and now defunct) forums. This is pretty much where people can submit completely crazy, new ideas and have them critiqued and further developed by their peers. It basically served as our "Skunk Works" where we tried to come up with things to out-innovate other teams. Also, since I was our "Idea Guy", it was a place to put everything I thought of so I could keep track of it.

Counter-Rotational Spinning Weapons, aka CRS Weapons

Our work with this concept started waaaay back in fall '05. Coriolis was the intended prototype robot, but due to complications with the design it had to be severely cut back to a mediocre vertical circular saw robot. The benefit of CRS weapons is that the counter-rotation negates any gyroscopic effects from sharp turns, resulting in extremely nimble & easy to control robots with powerful spinning weapons. The other hypothetical benefit is increased damage in the form of shearing; the primary configuration it was intended for was two vertical spinning disks, placed one disk thickness away from the other. When the two disks struck a target, the idea was that it would wrench the material very sharply in two different directions, resulting in a large tear in the material.

The current progress with CRS weapons is still on the drawing board. However, I still feel that one could be made without too much trouble.

Kinetic Energy Batteries

Ever since we saw the first video of Warrior SKF, a Team Whyachi robot, we wanted to make our own version. Warrior SKF is a spinner that can harness the stored energy in its spinning ring to activate a flipper, throwing heavyweight robots six feet into the air (or more). The advantages of such a design are obvious: all the power of spinning weapons, with the precise control of spring/pneumatic/electric weapons. Our first attempt was X-Revolution, which used a three pound section off of some part of a jet engine as the spinning shell. It was also to use a flipper, which was a variant of X-Contamination's own flipper. Unfortunately, since we didn't have any good way to lock the flipper into the shell, it didn't work.

More recently, I've put some work into the concept and have something sitting in CAD that I think would work properly. It's a drum enclosed inside the robot, with a shaft that comes into contact with it and is pushed linearly (I'll find some screen shots and put them up here to clarify). The main disadvantages with my design are the potential for the shaft to break (I have no idea whether it would be able to hold up to being struck by the drum), complexity of the whole assembly (it requires a small microcontroller and sensors to properly time its operation), and the assembly's size. Still, I think it has a reasonable chance of working.

Legal Directed Energy Weapons

First, a link:

http://www.wickedlasers.com/lasers/Wicked_Lights-74-0.html

That is a 100 Watt halogen bulb mounted in a flashlight run off of a 14.4V 1500mAh NiMH battery. As the videos on the site show, you can do all kinds of fun things with it, like light paper on fire, ignite an entire book of matches, scramble eggs, etc. This is a pretty reasonable power draw, so you could probably pack two or three bulbs into a single (or multiple) reflector(s) on a robot.
The reasons I think this may be legal under Battlebots rules are:

1. It is only effective at very close range
2. The best configuration would likely be some kind of arm that remains raised most of the time with the light aimed downward. The arm would clamp down and hold onto the other robot, and a small momentary switch would close the circuit to the lamp upon making contact with the target's surface. This gets around the whole "Don't blind your opponents with lights" rule.

This weapon type would be hit or miss. Robots with acrylic or lexan for their top armor plate would understandably be more affected by a high-powered lamp than one with an aluminum plate. Damage would manifest itself in either the armor (if it is a polymer), and/or by overheating the internal components (particularly ESCs, Receivers, and Batteries).

No work on this concept has gone beyond this stage.

Modified Threshers

From seeing what happened to Knightrous' thresher at the 2008 Nationals, I think I may have a solution. Hardened steel is often more brittle than it would be otherwise, so if one made a two or three-part thresher with a softer steel and hardened steel plates used as the striking surfaces mounted onto the surface, catastrophic failure can be avoided with a minimal increase in machining difficulty and possibly a decrease in overall cost for the thresher.

EDIT [3/28/09]: This is apparently a viable and not terribly uncommon design, according to the RioBotz guide. The main consideration one must take though is "how often do you want to replace it?" Magnesium alloy or Aluminum alloy main bodies tend to take damage more than Titanium bodies.

Emissary42 wrote:

Modified Threshers

From seeing what happened to Knightrous' thresher at the 2008 Nationals, I think I may have a solution. Hardened steel is often more brittle than it would be otherwise, so if one made a two or three-part thresher with a softer steel and hardened steel plates used as the striking surfaces mounted onto the surface, catastrophic failure can be avoided with a minimal increase in machining difficulty and possibly a decrease in overall cost for the thresher.

With the force the have they would bend the softer steel i think, and im pretty sure the thresher on knightrous was to hard

HarrisC wrote:

With the force the have they would bend the softer steel i think, and im pretty sure the thresher on knightrous was to hard

It was Hardened S7 Tool Steel... They use that shit for Jackhammer bits... It is supposed to be nearly impact invulnerable. I mean, that type of steel is used SPECIFICALLY when a high impact environment is likely...

I think it was Vince(or maybe Eddie) who told one of his professors that our drum has basically sheared a thick piece of Hardened S7 Tool Steel and the professor's reply was "No you didn't"
That sort of impact isn't something you see every day.

Anyway, that sort of hit was definitely amplified by the fact that we had gotten flipped. So it was our force down plus their force up...

I wouldnt say that your drum sheared there thresher at all when you increase rockwell hardness brittleness also increases, the fact that you were upside down also adds alot to the kinetic energy in that impact. As you were saying bloomsburg high school over hardened the teeth on executer before (as i believe BCA did) and ended up breaking of a tooth on there drum in a fight against mini knightrous, throwing the weapon off balance and shook the screws out of there bot

HarrisC wrote:

I wouldnt say that your drum sheared there thresher at all when you increase rockwell hardness brittleness also increases, the fact that you were upside down also adds alot to the kinetic energy in that impact. As you were saying bloomsburg high school over hardened the teeth on executer before (as i believe BCA did) and ended up breaking of a tooth on there drum in a fight against mini knightrous, throwing the weapon off balance and shook the screws out of there bot

That is true. Sheared wasn't the right word...
We broke it...

And while hardening it does increase brittleness, as I said above, S7 Tool Steel is specifically well suited for high impact applications. Unless they completely overdid the hardening, it would have still been ridiculous to say that it is even necessarily possible to cause that sort of catastrophic damage in the 120 lb competition... There was a good reason for them picking S7 Tool Steel. And there is also a reason for the almost forced retirement of the bot after that... You don't just go replacing S7 Tool Steel on a whim.

But like you said, our two weapons hit going the opposite directions... So the force was MUCH higher than it would have been otherwise.

The Mach Spinner

The name is fairly descriptive here: make a spinning weapon whose edge breaks the sound barrier. Why, you ask? Because of the look on people's faces when it spins up in the test box, that's why!
The design of this weapon would diverge greatly from the typical spinning weapon formula. The spinning component would be very light, as incredible energy would be available from its speed alone. The best choice I decided was steel cable; it's sufficiently light, can be balanced by ever so slightly moving it one direction or another in its mount, is strong, and would also be easy to replace. The weapon would be in effect a giant weedwhacker. A giant weedwhacker that could do horrible things to other robots.
The motor of choice would be either a series of extremely high-torque motors geared down to an obscene ratio, or a directly-driven fully custom brushless motor, with reduced friction in the form of passive or active maglev (could potentially be handled with a clever arrangement of permanent neodymium magnets). Large heat sinks and possibly some form of liquid cooling may be necessary. Providing sufficient electrical power would likely fall to a bank of Lithium Nanophosphate batteries being constantly charged by an internal combustion engine running an alternator at full tilt.
In standard operation, the weapon would not be brought up to an RPM capable of putting the cable tips to Mach 1--that would just be to show off, or in emergencies that required that kind of energy.

Insignificant work has been done on such a weapon much beyond this stage, but it should be possible with great care in its design and the appropriate resources.

My $0.02:

From the materials class I'm taking right now, I am comfortable telling you you sheared a thresher made of S7. For one, the two drums striking in the manner they did is almost ideal to create the strongest force possible. Second, that thresher had been in operation without replacement for several years. This isn't a major thing, but it contributes to shifting the original defects in the steel over time. Example: anyone ever replaced a metal guitar string before? The reason you pull on the string is to force defects in the individual crystals making up the string to move to the boundaries of the crystal. I'm not sure what effect this would have on a thresher though, but it would not only result in the movement of defects but also generate new ones. Finally, 99.999% of all breaks in anything is via shearing in one way or another. The only other option would be that you exceeded the tensile strength of S7 steel, and I think we can all agree on what is more likely.
Then again, I could be wrong. If you'd like I can ask my materials professor and settle this mystery once and for all.

EDIT [8/2009]: It's very likely instead of defects shifting around that many small cracks formed in the steel over the course of three years - this would make shearing the thresher MUCH easier, and is a pretty reasonable explanation.

Note: the modified thresher is a good example of many of the things I come up with: it's an interesting idea, but probably not the most effective - at least not without further refinement. I also come up with ideas that are just plain nuts. For further examples of those, see "Mach Spinner".

Emissary42 wrote:

The Mach Spinner

The name is fairly descriptive here: make a spinning weapon whose edge breaks the sound barrier. Why, you ask? Because of the look on people's faces when it spins up in the test box, that's why!
The design of this weapon would diverge greatly from the typical spinning weapon formula. The spinning component would be very light, as incredible energy would be available from its speed alone. The best choice I decided was steel cable; it's sufficiently light, can be balanced by ever so slightly moving it one direction or another in its mount, is strong, and would also be easy to replace. The weapon would be in effect a giant weedwhacker. A giant weedwhacker that could do horrible things to other robots.
The motor of choice would be either a series of extremely high-torque motors geared down to an obscene ratio, or a directly-driven fully custom brushless motor, with reduced friction in the form of passive or active maglev (could potentially be handled with a clever arrangement of permanent neodymium magnets). Large heat sinks and possibly some form of liquid cooling may be necessary. Providing sufficient electrical power would likely fall to a bank of Lithium Nanophosphate batteries being constantly charged by an internal combustion engine running an alternator at full tilt.
In standard operation, the weapon would not be brought up to an RPM capable of putting the cable tips to Mach 1--that would just be to show off, or in emergencies that required that kind of energy.

Insignificant work has been done on such a weapon much beyond this stage, but it should be possible with great care in its design and the appropriate resources.

Julien has been enamored with a concept similar to this.
I doubt that it would be practical and useful for an actual match though...

Anyway, one of the other interesting side effects of having a spinning blade of sorts going past Mach 1 is the fact that it would be a continuous boom rather than just a single, short boom. Reason for this is you would pull the sonic boom around behind the steel cable and, because it is spinning in a circle, you would produce a pretty much constant boom. I am not sure if it would even be safe, because you may or may not accidentally burst eardrums with that sort of sonic boom.

Emissary42 wrote:

It's a drum enclosed inside the robot, with a shaft that comes into contact with it and is pushed linearly (I'll find some screen shots and put them up here to clarify). The main disadvantages with my design are the potential for the shaft to break (I have no idea whether it would be able to hold up to being struck by the drum), complexity of the whole assembly (it requires a small microcontroller and sensors to properly time its operation), and the assembly's size. Still, I think it has a reasonable chance of working.

I was thinking a lot about this... The shaft would definitely have to be quite strong, but you would need some sort of very fast actuator to push the drum into the bar... like you use the trainer switch on a spektrum controller, and that goes to a solenoid or something to activate the actuator. Not sure how you'd go about doing THIS, but you could do something like what Team Whyachi did, and have the other half of the drum exposed, so that you can use that as a secondary (or hey, even primary) weapon. Their ring stopped spinning completely when it hit, but i don't think the drum would have to. Yes, it would slow down significantly, but we could immediately flip the bot around, spin it back up and hit them with it.

I'll clarify in the Kinetic Energy Battery thread a bit more once I get back to a computer with an actual keyboard, but in my assembly the axle of the drum is parallel to the shaft that is struck & driven forward. The drum has a raised helical protrusion running up its surface, and the shaft has a raised section that is brought into contact with the protrusion by rotating the shaft.

Full-Body Drum

Will spotted these a few years back, and I decided to take a bit of a closer look into them (scroll down until you see Daffodil versions 1 & 2):

http://www.happyrobots.com/retired.html

Pretty straightforward, it could be advantageous because you get to use most of your weight toward the drum & internals, as opposed to using it towards the typical chassis & armor configuration. I would actually make one change to the above design (mainly for the now-popular large-diameter drums): Instead of two large wheels, have three smaller wheels geared into the output shaft of your gearbox in a planetary configuration - all three wheels will rotate in the same direction, maybe getting you something closer to a tank drive than just a two-wheel drive.

Polymer/Composite Spinning Weapons

With the incredible advances in polymer and composite technology, there now exists some pretty fantastic materials that are incredibly strong and lightweight. My idea boils down to this: I'm pretty sure one could make a spinning weapon of some kind with a structural frame made of a strong, lightweight polymer or composite (like some of the carbon-fiber/mylar or graphite weaves on the market) as a structural skeleton. The mass and striking surfaces would of course be other materials - striking surface either a hardened steel, titanium, or carbide; the mass provided either in the form of measured amounts of concrete molded in PVC pipes, or possibly high-density metals such as tungsten billets/rods.

The nice thing about such a weapon would be that you could make it have exactly the characteristics you wanted - you could determine how its mass is distributed, exactly how "dense" the weapon is, instead of just overall size and rotational speed. The only thing I'm not sure about is cost; making a sufficiently strong skeleton would not be cheap. I'm fairly certain it could be done though.

I believe it was Olathe tried making there drum on a 120 out of some sort of polymer and had it blow up on there first hit

Yeah. That's the one problem there: if it isn't perfect, you've got a big chance for some horrific structural failures. I'll take a look at pictures of their robot before and after. It should be possible to make one, but very, very difficult figuring out what will work without having it explode after a few uses.

yeah, but i'm not sure all that much thought went into olathe's optimus prime. The weapon itself wasn't any fancy polymer, just BLACK DELRIN. the design was retarded (the point with maximum stress was the thinnest on the entire weapon) and it had ALUMINUM BLADES. Clearly their design wasn't quite as "revolutionary" as you're giving them credit for....

I've never seen such a weapon, actually. I just thought of this out of the blue today.

here's what optimus prime did -




if the video isn't processed yet, it will be eventually...

Ok, I kinda see what they did there. Sort of a pity they didn't put more time into the initial design. Although what I have in mind will probably run a few hundred $ just to develop for mini-scale. It would take quite some time with a CAD program running stress analysis, and just plain-old pen & paper before I was comfortable to go to that stage even.

Did you guys no that mini blender had a 3D printed chasis?!

Huh, That's pretty cool actually. What material, nylon?

MMmmm im not to sure actually i dont even remember where i found that out. I dont think its on his website anymore. I do admit the kid comes up with some innovative ideas, i love the way he's mounted the weapon motors on his redesigned miniblender!
mini blender site