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Topic: How to power drone motor without lipo (Read 1 time) previous topic - next topic

HermannSW

#15
Jun 26, 2018, 10:12 pm Last Edit: Jun 26, 2018, 10:43 pm by HermannSW
I tried an even thicker cable (extracted from a mains power cable), with 35cm a little bit shorter, and that resulted in unlimited drone flight time! I played with the drone for more than 40 minutes without pause, that is the reason I think there is no limit. The problem is that the cables are too stiff, flying is really difficult with them.

Because flying is so difficult I used a trick, making it easier to keep the drone from escaping:
https://www.youtube.com/watch?v=SxKZArpUTOY



So this proves that unlimited inhouse drone flight is possible, Next steps are to determine which lighter and less stiff cables do works as well, to gain full flight control and probably a little bit more range.

P.S:
The two 35cm cables do weigh only 7.8g, still 4.5g left for longer cables (reaching weight of lipo missing now).
stepper PT camera system:
https://forum.arduino.cc/index.php?topic=647703.0
high precision linear actuator:
https://forum.arduino.cc/index.php?topic=645745.0
http://stamm-wilbrandt.de/en/Raspberry_camera.html

Sunnytec

So this proves that unlimited inhouse drone flight is possible, Next steps are to determine which lighter and less stiff cables do works as well, to gain full flight control and probably a little bit more range.
Good job!
I've always wondered about doing the same thing. And I also dream of longer cables....

Ideas on your project:
You could do your own buck converter with a Zener diode, it will probably weight less. I believe it won't reach 15g (example).

With a buck converter attached to the drone, you would not need the thicker cables.

MorganS

That is a rather misleading page. Did you notice that the only difference between the two switching circuits is that the switch is drawn either open or closed?

The final circuit with the zener is not a switchmode converter. Buried in the last paragraph is "linear mode". In fact, that is an extraordinarily inefficient linear regulator. A 7812 could replace that circuit and give significantly better performance.
"The problem is in the code you didn't post."

HermannSW

#18
Jul 08, 2018, 09:39 am Last Edit: Jul 08, 2018, 09:50 am by HermannSW
You could do your own buck converter with a Zener diode, it will probably weight less. I believe it won't reach 15g
This might be an idea for bigger drones, but the drone I used does weigh 50g only (I cannot weigh now, see below, but amazon says item weight is 1.76 ounces).

The buck step down converter I use that is able to handle up to 12A does weigh 81g ...

Quote
With a buck converter attached to the drone, you would not need the thicker cables.
In case the buck converter would be 15g as you said it would be even heavier than the 12.8g of the lipo shipped with the drone. With the additional cable weight that might avoid drone take off due to overload.


I did order recently a 150W 12V (12.5A) mains adapter from Amazon which seemed to be a better fit than the 170W 20V (8.5A) laptop mains adapter because I am only interested in 3.7-4.2V in the end. Unfortunately on first connection to mains it gave a very loud bang and blowed the room fuse. I already got it retruned and refunded, waiting for the reorder to arrive.


Currently I cannot do experiments with that drone because I lost it in another tree while on a new search mission for the RC airplane:
https://www.raspberrypi.org/forums/viewtopic.php?f=43&t=190407&sid=25471160e58720b71f95f6da16519f57&start=25#p1333694

I like scotty101 comment on my postiong ;-)
Quote
You are going to buy another drone, to find a drone that was lost while finding an RC aircraft.. Perhaps you need to stop flying near trees?  :lol:
Anyway, new FPV Eachine E52 drone (only 20$ with free shipping during banggood super sale!) arrived and I already did first flight exercises. Camera FPV on android smartphone should find the lost RC drone in 5-10m high small group of trees and rescue with 7m long ladder. And hopefully later get better location of 20m height tree RC airplane location and probably help in rescue that as well.

These are three slowed down from 30fps to 6fps parts from >60 flights that showed the airplane. First airplane enters scene from top right to middle right hidden by leaves, then plane enters frame from middle top and leaves top left, and finally plane enters from middle top and leaves middle top:
stepper PT camera system:
https://forum.arduino.cc/index.php?topic=647703.0
high precision linear actuator:
https://forum.arduino.cc/index.php?topic=645745.0
http://stamm-wilbrandt.de/en/Raspberry_camera.html

HermannSW

#19
Jul 10, 2018, 01:28 am Last Edit: Jul 13, 2018, 10:06 am by HermannSW
I did quite some more excercise flights, no problem after I spent 24$ (more than for the E52 itself) for 5 lipos with 5xcharger cable:



Taking videos in the evening after sunset had some issues wrt contrast when heaven comes into view, but the camera resolution was a surprise, 720x576 is 0.4MP and not the the 0.3MP from E52 description:



I did it again today, lost the drone two times, in high grass this time and not in trees. The turn drone motor on/off trick I used to acoustically locate the other drone did not work. But since the drone is an access point I used the Wifi strength (very coarse, 0-4 arcs) to find the drone both times (turn WLAN off in Android, then on again)! For the next searches I am better prepared after installing Wifi Analyzer app, much more fine grained connection information (here tested with drone at home from next room):




Today the reordered 150W 12V (12.5A) mains adapter arrived as well, worked this time without issues. Will try that after having found and rescued the first lost drone with buck step down converter instead of the 170W 20V (8.5A) laptop power adapter.


P.S:
I did real searches for drone landed in deep grass with Wifi Analyzer.
Especially enabling sound made it easy to find the drone:
https://www.raspberrypi.org/forums/viewtopic.php?f=43&t=190407&p=1340160#p1339506
stepper PT camera system:
https://forum.arduino.cc/index.php?topic=647703.0
high precision linear actuator:
https://forum.arduino.cc/index.php?topic=645745.0
http://stamm-wilbrandt.de/en/Raspberry_camera.html

manu793

Good. Wireless may be more good. Latest BLDC motor should be used.

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