Tethered drone "pop-up" router.

[hasty lake]

@frozen galleon I did a drone test yesterday

[frozen galleon]

The cool thing about the kinematics of a teather is that you only need one motor and prop.

plus its easily fully waterproof.

[hasty lake]

Oh you mean a tether would supply power?

[frozen galleon]

yes

this lets the flight end be much lighter and removes any endurance issue

[hasty lake]

I created a thread for a Meshtastic rc plane

Planning on building a glider with a node in it

@frozen galleon this is more for for #1197926994411794543

[frozen galleon]

ok

[steady flax]

Also removes a safety issue. If you're using a lighter than air solution and the tether snaps, you now have a balloon quickly wandering through controlled airspace. With a quadcopter and maybe a smol emergency battery on board, you can have stationkeeping and if the tether snaps, it comes down one way or another. Preferably using the onboard smol battery for autoland but uh, one way or another it will land c:

(speaking of which, a quadrotor can be designed to windmill if the rotors lose power, so it would come down less like a brick and more like a sycamore seed)

[frosty raptor]

If were doing "tethered"... then the stability of a quad probably isnt needed... just needs to hold altitude.

Could probably get by with a twin rotor.

[steady flax]

heh, mini chinook. I dunno how stable that would be as far as keeping an antenna pointed where it's supposed to though. Like with a quad, even if it gets blown about a bit or wanders around the GPS point, it tends to stay "flat" until you go crazy speeds to the point where aerodynamics takes over and says "lol no your propellers are wings now".

that and I'm not sure what would be more cost effective. As much as twin-rotors would have less parts, quads are mass produced.

Unless you mean the coaxial helicopter types, which do the whole swashplate thing for control. That has its own issues.

[frosty raptor]

No swashplates... but maybe you're right. Quads are nice and stable... might be best suited.

[red hinge]

may as well use a chute

[steady flax]

perhaps, if you can make a mechanism that will absolutely work and a chute that will absolutely unfold properly. Might be a good backup if the tether snaps and the onboard emergency power is pooped.

though like I say, made light enough and with motors that aren't too resistant when unpowered, you can make a quadrotor basically windmill itself down. It won't be a super soft landing, but it won't be a brick falling either.

would be enough that if it lands on grass it'd be usable again 😛

[red hinge]

Use one of those model rocket chutes

and if the tether breaks, have a secondary circuit that lights the rocket motor

when the motor dies, the chute deploys

taps side of head

[haughty mauve]

https://www.youtube.com/watch?v=o6wspzT_Oj8&ab_channel=DustinDunnill

I've acquired this drone for deploying high nodes and velcroing a t-echo to

[steady flax]

You planning on dropping the node off somewhere high, or just holding there for the life of the battery? Just wondering how you'd un-stick the velcro remotely >.>

[red hinge]

The idea here is that the drone is on a power cord

so it can fly forever

[haughty mauve]

Nah, just flying up to 400' for like 10 minutes to see what I can see.

It's main purpose for me is to drop magnetic solar nodes on top of silos and stuff.

[haughty mauve]

That's a stage 2 see if I can do it sort of thing. Would take a hell of a big long cord to keep this drone's battery charged in flight.

I have a hunch I'd reach my 8lb limit on that cord before I get to 400'

[red hinge]

You don't need a large gauge wire for the amount of power a drone uses

even a big drone

[steady flax]

oh for 10 minutes you wouldn't even need a tether. But for permanent installation, you'll need a power delivery system. Would also help keep the quad in one place as a failsafe.

And you'd probably need a fairly thick wire, or high voltages and some step up/step down at each end.

quadrotor could easy use a couple hundred watts if it has to ramp the motors up to fight wind.

but ye if you're just dropping nodes, have a look at mechanisms the Ukrainians are using right now to drop, uh, more spicy packages 😛

#actually_a_bomb

or even more fun, integrate the quadrotor and the node so you can fly the lot up there, use the solar to charge a battery that both the quad and the node use.

worm gear with a nice amount of torque to lower and raise a magnet on a rail for fixing it in place.

[honest geyser]

higher voltage = more efficient drone and thinner cables, from my understanding

assuming the drone is tethered to power on the ground

it would be interesting to see how one would assure the drone could stay up in bad weather and such

hobby grade drone parts made for 8s batteries are relatively accessible

[honest geyser]

this would look really silly i wanna see it

youd probably want two counter rotating props though, otherwise it would spin a lot

[frozen galleon]

Would duct it

[honest geyser]

would that help with the spinning?

i always thought it was more of an equal and opposite reaction thing

[steady flax]

yeah even an EDF would need some external controls, maybe flaps in the exhaust stream or whatever. It would be a finicky and rather custom solution that, while possible... I'm not sure how viable it would be versus just going with the mass produced option.

EDFs can have hella torque. This one was a hell of a jerk if I powered it up from zero while holding it. https://www.youtube.com/watch?v=0x2mbEVqJW4

on the upside it'd probably have easy enough power to lift a heltec 😛

You might also notice that EDFs are not very quiet. It's like a flying leaf blower c:

[haughty mauve]

I use a SwellPro Fisherman Max which already has a dual release built into it and can lift 8lbs. Kind of a cool drone

[frozen galleon]

The torsion of the tether and the edf duct vanes can counter any rotation, you don't need active control.

In any case the solution is just more thrust.

The whole point of the pop up is to quickly get say a 40m AGL in a specific area.

For extend periods

[steady flax]

sure but you also need stability. With a single EDF on a tether, you're basically running a rocket engine on a string with no vectored thrust.

You would need either some exhaust vanes, or a tricopter/quadcopter arrangement. Otherwise it'll go everywhere.

with a guided platform, be it directed-exhaust or quadrotor, the tether is just a safety device and power delivery. The platform stationkeeps itself. That and this is a very solved problem and there are firmwares and flight controller boards out there that will do what you want for relatively cheaps. c:

take it from me, that EF-16 is intentionally close to unstable so it's reasonably aerobatic. It needs constant control input. An EDF on a string would be hilariously unstable.

https://en.wikipedia.org/wiki/Rocket#Pendulum_rocket_fallacy also bear this in mind.

[red hinge]

The best solution for a popup would be a helium based system with some way to reclaim the helium

a THICK mylar baloon that's always inflated

those stay bouyant for a long, long time

there are pumps for reclaiming helium back into the cannister

Apparently it's not terribly cost effective - the pumps look expensive

I do wonder if just bulk storing helium is a better solution.

alternately, creating hydrogen

[steady flax]

hydrogen generation is not expensive, but it is slow and a fire risk. 😛

[steady flax]

(would also mean a comparitively large balloon to carry the node and the weight of the tether, and I've already mentioned what happens if the tether snaps).

think the last thing anybody needs in these, er, interesting times, is another balloon incident c:

[red hinge]

people launch sounding balloons in the US all the time

they rise until they hit the stratosphere, burst and fall to earth

The issue with the chinese one is that it was MUCH larger and used ballast to maintain a neutral bouyancy

[steady flax]

yeah and even in the US, you're really supposed to contact the FAA to just be sending shit up through controlled airspace. I mean it's not hard to do, but that's the step most youtubers don't show you because it's boring 😛

and it's not so much the follow-the-rules aspect, more the safety aspect and the saving some poor sod in ATC's headache when they see your giant mylar monstrosity beeping on their radar with no beacon c:

[red hinge]

yep

someday an airliner will ingest one and it'll be outlawed

[sick siren]

https://tenor.com/view/f22-air-force-jet-gif-26074657

But I wanna see the improv airshow when they shoot it down!

[dusty gulch]

why not use a coaxial helicopter design, like the nasa ingenuity?
just the motor, the 2 props and a rak wisblok with an lightweight antenna. such copters are buyable in the form of toys, readily built.
then mod it to be tethered.

its an idea i had for quite some time now, the main problem is the weight of the tether/cable. especially if you want to reach some interestings heights.. i mean, i dont care about 30m, a tree can do that. i want 50-100m

12v 6Ah or 12Ah lifepo4, maybe with a solar cell.. all tightly packed into a small pelicase including the copter (maybe with some clever folding design choices in the long run/final version).. pop the case open, press a button and the copter starts climbing until it reaches the end of the thether.. (or you stopped the tether).

im pretty sure 100m is a bit overkill.. but yeah.. still, the weight of the cable and "position" holding.. those are the main issues in my opinion

[steady flax]

I have a couple coaxials myself. They're fun toys, but they're as energy-hungry as a similar sized quadcopter, not as stable, not as aerobatic, and generally don't windmill. They also have the same kind of fiddly complex swashplate thing going on, whereas a quadrotor is comparitively simple in terms of just applying different throttle levels to different props.

[steady flax]

100m is 330ft. Below controlled airspace, but you'd probably still want a chain of blinky red LEDs on the device and its cable c:

https://www.youtube.com/watch?v=1vAC9xms4i4 essentially you'll pay way more on a coaxial that can do this over a quadrotor.