No. Lexan would work better. I don’t think Mechanums would do anything
They would let the drone S T R A F E
Isn’t the definition of a robot include a “wheel base” or “chassis” or something like that referring to driveing? (And not flying)
Edit: I guess it could be argued a drone would pass…
Subsystem 1: Mobile robotic base including wheels, tracks, legs, or any other mechanism that allows the robot to navigate the majority of the flat playing field surface. For a stationary robot, the robotic base without wheels would be considered Subsystem 1.
Subsystem 2: Power and control system that includes a legal VEX battery, a legal VEX control system, and associated motors for the mobile robotic base.
Subsystem 3: Additional mechanisms (and associated motors) that allow manipulation of game objects or navigation of field obstacles
Drone Calculations_v2.pdf (189.1 KB)
There’s the revised calculations. A speed gear ratio of with High Speed Gear Cartridges would be a bit much. I think the most efficient drones will be 1:1 with High Speed Gear Cartridges, or 1:3 with Standard Gear Cartridges.
I think a drone with eight motors would be a large drain on your battery, but I like the idea of being more inventive with drones. My ultimate dream would be a 2 motor drone with servos rotating the propeller modules, like the V-22 Osprey.
THIS IS BEUTIFULL… thank you now I think the frame needs to be adressed
I’m working on building one in Inventor at the moment
A v5 drone would be too heavy and not have the power to fly. If you compare the v5 components to commercial drone parts, the v5 parts are heavier, and put out much less power than their lightweight brushless counterparts. If you are interested in making a drone, I would recommend going to https://oscarliang.com/ which has a bunch of information on drones and multi rotors.
It [might] have been done with cortex in the past. I’m still not sure if I believe @JamesChase7422C’s claim that he built a working prototype.
like I said it didnt exactly work well
Hovering for 30 seconds is WAY better than anyone else, EVER
People at my school tried building a helicopter last year after we failed at state. It’s been a running joke of a helicopter bot for 4 years now. We used cortex obviously and the gearing was super high, don’t know/remember all the details. We were just trying to get lift, not navigate. All I know is that it spun for a couple seconds and then fell apart. Probably from crappy building though and it was like a day fling I think.
We’ve thought about trying it with V5s but I think they’re too heavy to achieve a helicopter.
But hey I’d be down to see someone try.
I’m not exactly sure what calculations were used to get a speed of 352 RPM to make a 10" propeller produce 1.07kg of thrust. I had a 10" propeller lying around and decided to test it. I recorded under 2 grams of thrust at 410 rpm. I would recommend having a look at some of the many thrust calculators people have put together to find a more accurate calculation.
I tried out this one: http://www.gobrushless.com/testing/thrust_calculator.php?prop=15&rb1=1&Value=410&Altitude=0&submit=Calculate+Now and the calculation that made for the same propeller and speed agrees with the data I measured in the real world.
Using the same calculator and same blade a speed of 7600 RPM would produce a thrust of about 1.07kg
To achieve these speeds you could use V5 motors with a 600RPM internal gearbox, then a 2 stage external gearbox with a 3:1 ratio for the first stage and then a 5:1 second stage. This would produce a final output speed of 9000RPM, which is probably far too fast.
Alternatively the 200rpm internal gearbox could be used, with a 2 stage external gearbox, this time 5:1 followed by 7:1. This would produce a final output speed of 7000RPM, a bit slow but would still produce nearly 900g of thrust per motor which might be enough.
Would a single V5 motor be able to spin a 10" propeller at 7000RPM?
Would the polycarbonate blades be strong enough to survive these speeds?
Unfortunately I think the answer is no to both of these, although I’d like to see someone give it a go!
An average 5" quad would have 20,000+ rpm.
Even if you managed to make a polycarb prop it would be pretty inefficient compared with a commercial prop.
Would be cool to try to make one with commercial props but I’m doubtful you could get the thrust to weight high enough. Plus there is the issue of having a decent enough gyro and accelerometers, and writing some pretty cool code to handle it all, although I guess there is plenty of examples already out there that could be used and tuned.
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Okay yeah, that makes sense.
The topic of drones came up in a thread a good while ago and I posted a reply that included a possible way to make a lighter structure for a drone. Then the thread kind of died and I never got a response about its legality. :P
I don’t think that would really save much weight, While I haven’t done the math for the weight savings it probably wouldn’t do that much. Also, I don’t think anyone’s seriously suggesting using it in a competition, because you would need even more weight to have a method of scoring. It’s more of a fun side project/massive flex in my opinion.
I had one question about your calculations:
I noticed that you used kg for a unit of force, when it’s really a unit of mass. I think you would need to multiply the mass of the whole thing by two (for the hover rule), and then by 9.806 m/s^2. Did you mean to use kilograms like that? @Dr.C-Channel