I need to know, like, really bad.
4 Likes
It needs to comply with the motor rules, the bumper rules, and the SAFETY rules, not necessarily in that order.
Otherwise, there are no rules explicitly prohibiting any sort of flying robot.
14 Likes
этот хорошо. this is good. thank you.
1 Like
I’m going to assume you mean legal in FRC. If so, then @EricH is correct, except that I’d add battery rules (R601, in 2022).
If you do the math on the power and energy density in an FRC battery, sustained flight is… extremely marginal, at best (it would have been completely out of the question before the introduction of brushless motors).
8 Likes
You could probably fly something tethered with power wires to the main chassis (holding the battery and bumpers). You’d have to be a good pilot though to stay within the frame extension limits. I can’t think of any reason you’d want to fly something instead of just elevating a pole, but maybe the OP is more creative than I am 
6 Likes
just covering all my bases here
3 Likes
I wouldn’t give it much serious thought. Inspectors are probably not going to pass a robot with a flying bit loosely tethered to the robot. There are refs, FTAs and spectators on the side of the field - none of whom want a propeller in the face.
4 Likes
Adding to this, I did mention the SAFETY rules.
Propellers are default unsafe. Shrouded propellers somewhat less so. We had that discussion back in 2009 and things have only gotten more powerful since then.
Exiting the field (and seriously, if you can guarantee that you’ll never leave the field with a flying robot, I’ve got a few bridges to sell ya) is default unsafe, particularly if you hit something or someone.
Tethers are an “interesting” option–but require some intent. Case in point: “Batman”, “Robin”, and “Alfred”, 148’s entry into the 2015 game, which were tethered together–but some of the lines connecting them were ruled a hazard and “Alfred” rarely if ever saw the field.
And then there’s the laws of physics. You need to lift the battery (15 lb), a minimum control system, the motors, the propellers, and the shrouds, plus structure, plus game piece and manipulator, plus bumpers (at another 15 lb). You’re going to need a really good prop or 8.
3 Likes
There is also the main breaker limiting the average current that can be drawn from a (perfect) battery. The current limit basically becomes a limit on the electrical energy you can feed into your motors, limiting the mechanical energy you have available to do anything.
If one draws sufficient energy from the battery to lift everything necessary, one would likely want to ensure that it has enough total stored energy to sustain that rate of energy usage for the time required.
@alexis_texis How much electrical energy will your scoring mechanisms consume or will they be totally passive? Will you be using pneumatic actuators in your scoring mechanisms? The pneumatics rules mandate the usage of certain compressors, all of which are pretty heavy.
The fundamental characteristics of the battery also works against you. As the current drawn from the battery rises, the output voltage falls. This also acts as a limit on the amount of electrical energy that can be drawn from the battery.
The GDC has stuck with this particular type of battery in spite of the availability of batteries that are able to support higher output currents. The GDC has consistently been not very transparent in sharing the intent of many of the rules. It is likely that the rules requiring particular batteries and main breaker are meant to serve as a limit on the amount of energy that teams have available to them ie the energy limit is part of the challenge ie the GDC wants teams “thinking harder inside the box”. In some forms of auto racing, there are various forms of energy limits ranging from intake restrictor plates, total fuel limits and engines that are all built by the same builder to the same spec and then are sealed to make any modifications easily detected.
1 Like
ChiefDelphi can be such a buzzkill sometimes. 
15 Likes
If you didn’t have to deal with pesky laws of physics, you probably could make a pretty decent drone that doesn’t violate any rules. But, like a lot of people have said here, I still don’t think an inspector would let a flying object of any kind in. Even if the blades were fully protected and very safe, there’s still a flying death machine metal airborne contraption. If you lose control and it crashes, it wouldn’t matter if the props are protected. It would still completely shred you have potential risk for severe injury and/or death.
6 Likes
Let’s just say, hypothetically, you could build an “FRC legal” robot that could lift off and hover, and contain the blades in a shroud. It’s possible you could limit the prop speed such that it could only hover in the ground effect region, and so the altitude was intrinsically limited. If you could limit that height to a few inches, so there was no possibility that it could exceed the arena side walls, then that might be enough to convince an LRI that it can’t escape the arena.
But if you’re going to do that, a hovercraft would be more practical.
7 Likes
If you’re flying at a few inches off the ground is there really a point to making a done? Might as well make a normal robot then. Cheaper, more practical and less risky. Anyways, how could you get a good enough T:W ratio to get airborne anyways? Those batteries are heavy, those mechanical parts are heavy, and so far there aren’t really any good props that aren’t crazy expensive for that to work.
Those pesky laws of physics ruining all the fun
2 Likes
Obviously we want to dunk a rapid react cargo 
11 Likes
Dear god, everybody needs to stop telling 4907 it can’t be done 
I can see it now, 4907’s 2023 robot flying (safely) through the crowds at champs…
15 Likes
It’d be pretty fun to see a hovercraft drivetrain. I mean, hey, aren’t hovercraft drives holonomic–might be cheaper than a bazillion falcons if the current trends keep up, eh?
7 Likes
To OP’s original question:
The task at hand: Do the math to figure out to what extent the constraints of the manual allow or prevent flight (for varying definitions of “flight”).
5 Likes
Even if it isn’t legal, it would still be pretty cool to build for demos and outreach (with the right safety measures of course)
3 Likes
Figure an absolute minimum weight setup to be about 30 lbs with the battery, required control system components, structure, and motors and whatnot. What size and speed of propeller(s) would you need to give that kind of thrust?
3 Likes
Propellers have been used successfully in FRC to gain a competitive advantage before, but in the horizontal rather than vertical direction. My favorites:
