Hey everyone!
I am a relative noob to the RC world, but lately I have a reason to dive in head first...
I have a small company that designs & builds various electrical / alt power gear, much of it oriented around HAM radio and portable / emergency power & communications.
We have been making progress on an R&D project that just won't die... we keep getting closer to something that might work. ;-)
The goal of the project:
A small, collapsible flying platform that can lift a communications antenna about 30' off of the ground and hold it fairly steady for anywhere from a few minutes to a few hours.
The antenna is a flexible whip, about 20" long and weighing 34 grams (not pictured).
Power for the system comes from a DC source on the ground.
Control of the system is limited to throttle only.
Weight of the tether (DC power, signal for throttle, and antenna feedline) at max (30') height is 500 - 700 grams.
Weight of the air frame (motors,chassis, flight control, etc. is about 300 grams.
Currently building around Black Widow 2204 motors (with ESC built in).
Using Naze32 rev5 FC with 5030 props.
Primary construction of chassis is 3D printed ABS.
A few questions:
Do I need to use a small buck converter to deliver 5 volts to the Naze? Information I am finding online is not clear... remember I am not running a BEC
What is a good way to control motor speed... use a servo tester as throttle? A PWM speed controller? Remember this control is on the ground, hard wired up to the platform.
Any thoughts on the Naze being able to maintain level hover despite wind or movement of the operator on the ground? We are not running a GPS and don't want to.
Thanks in advance for your thoughts!
Replies
Tom,
That is good info: "arming can be turned off" because I am learning that is one of the issues... I bought the OpenPilot mini CC3D a couple days ago, this one:
What is a 'fw'?
firmware?
Yes, firmware... can you tell I don't know anything, LOL.
Tau Labs is an open source project for FW development... (google is my friend).
interesting....
You have to choose a firmware for that controller and upload to it, then you have to download the software to configure it and configure it for your cuad,
I don't have that cotroller but I think there is a specific forum of that controller were you can find more info and help, for shure Google is going to help you; perhaps You Tube helps too ;) Good Luck.
Why use an FC at all?
Use a weighted rigid shaft below to offset the weight of the antenna on top. Still attach your tether at the center of gravity, not the bottom of the plumb.
Tethered antenna.jpg
JoeBob,
I like the way you think. ;-)
We tried something similar early on, but we were using four lengths of 1/8" fiberglass rods, about 14" long, arranged like splayed feet, with small weights at the bottom. Response was a bit sluggish (reaction to being pushed / pulled away from horizontal) but it did react...
I rather like your idea... the single vertical rod would be easy enough to try...
The longer the down rod is, the less weight you'll need. Think of it as a lever.
If you make it strong enough, you can use the downrod for hand launch and retrieval.
I think the tether should be 1.5~2 times longer than the distance from the ground. Maybe the tether should be on a spring loaded reel.
Maybe optical flow and a laser altimeter could be the solutions for holding the position.
FWIW
I've made lots of tethered flights, and tangling in the props/motors was never close to a problem. (Especially with the weight of this tether).
Nor was there any problem with the flight controller stabilizing itself when it was jerked back by the tether.
Except when a strong wind carried it, laterally, to the end of the tether - then, look out!
George
What, like a lawn dart? Spiked, right?
Any thoughts on mitigating this?
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