Electromagnet for drone recovery system

[slozukimc]

I am trying to come up with a way to pick up and release stranded/broken drones from a heavy lift drone with a winch mounted to the bottom.

I have been thinking about an electromagnet. I found one that says it can lift 5 pounds or so and runs on 5vdc. The winch and electromagnet will have their own battery.

My question is this: Does anyone see an electromagnet deployed from a winch on the bottom of my S900 causing any sort of interference with the A2 flight control system?

I am picturing a steel washer epoxied to the drone I am recovering for the magnet to stick to.

It’s all just in the planning so far. Any ideas or comments are welcome.

Thanks, Mike

 

[Ty Pilot]

I am trying to come up with a way to pick up and release stranded/broken drones from a heavy lift drone with a winch mounted to the bottom.

I have been thinking about an electromagnet. I found one that says it can lift 5 pounds or so and runs on 5vdc. The winch and electromagnet will have their own battery.

My question is this: Does anyone see an electromagnet deployed from a winch on the bottom of my S900 causing any sort of interference with the A2 flight control system?

I am picturing a steel washer epoxied to the drone I am recovering for the magnet to stick to.

It’s all just in the planning so far. Any ideas or comments are welcome.

Thanks, Mike

So you intend to use a (heavy lift) drone to rescue stranded or crashed drones. Assuming that the allowance for payload of equipment and stranded/rescued drone are covered, the biggest problem I see is:

If there is a stranded drone that you can't physically reach (otherwise it is not stranded) - how are you going to epoxy the steel washer to the stranded drone so as to allow for the electro magnet to work?

Personally, I would ditch the idea of an electro magnet and a winch as these both add dead weight and complexity. The electro magnet needs a powers source and as mentioned - what is it going to attach to when most drones are plastic? The winch is redundant when; assuming you have to be directly over the target anyway, thus clear of any obstructions in the vertical, the raising and lowering of the drone effectively does the same thing.

You might want to just try some simple experimenting with a tether line with some sort of grappling hook and see if you can even achieve a 'rescue' under the best conditions such as in an open field a few feet away. Through simple experimenting you will begin to find any shortcomings and what works and what doesn't.

 

[dirkclod]

Seems I saw a grappling hook somewhere that had 3 or 4 fingers
that stayed closed till it was sat on whatever then the weight above
the fingers opened them up to grasp whatever. And when you pulled up they closed. Seems in was in PhantomPilots way back.
I will see if I can’t find that thread.

 

[Yorkshire_Pud]

I would be worried about the electromagnet's magmetism damaging some thing in the drone or maybe the motor magnets.
Some sort of mechanical grab seems a better idea to me but you must be able to release it remotely or be able to unhook the captured drone remotely, just in case the captured drone gets stuck.

 

[slozukimc]

So you intend to use a (heavy lift) drone to rescue stranded or crashed drones. Assuming that the allowance for payload of equipment and stranded/rescued drone are covered, the biggest problem I see is:

If there is a stranded drone that you can't physically reach (otherwise it is not stranded) - how are you going to epoxy the steel washer to the stranded drone so as to allow for the electro magnet to work?

Personally, I would ditch the idea of an electro magnet and a winch as these both add dead weight and complexity. The electro magnet needs a powers source and as mentioned - what is it going to attach to when most drones are plastic? The winch is redundant when; assuming you have to be directly over the target anyway, thus clear of any obstructions in the vertical, the raising and lowering of the drone effectively does the same thing.

You might want to just try some simple experimenting with a tether line with some sort of grappling hook and see if you can even achieve a 'rescue' under the best conditions such as in an open field a few feet away. Through simple experimenting you will begin to find any shortcomings and what works and what doesn't.

My S900 has plenty of lifting power to recover the drones I am playing with and then some. It will lift 14 pounds effectively even in wind.

The drones I am recovering will have the washer epoxied before their staged crash. This is for a specific video I am attempting to produce rather than being able to rescue others drones.

I thought about just using a tether but I am scared of it getting caught up and not being able to get my drone out of trouble. With the tiny RC truck winch if I wrap the line right I should be able to release all of it and get away. The power to the electromagnet is my problem there.

I was looking at the electromagnet rather than a regular one so it could be turned off until the S900 is in place and ready to attach.

Thanks!!

Mike

 

[Ty Pilot]

The drones I am recovering will have the washer epoxied before their staged crash. This is for a specific video I am attempting to produce rather than being able to rescue others drones.


Thanks!!

Mike

Ah okay, got it.

 

[dirkclod]

My S900 has plenty of lifting power to recover the drones I am playing with and then some. It will lift 14 pounds effectively even in wind.

The drones I am recovering will have the washer epoxied before their staged crash. This is for a specific video I am attempting to produce rather than being able to rescue others drones.

I thought about just using a tether but I am scared of it getting caught up and not being able to get my drone out of trouble. With the tiny RC truck winch if I wrap the line right I should be able to release all of it and get away. The power to the electromagnet is my problem there.

I was looking at the electromagnet rather than a regular one so it could be turned off until the S900 is in place and ready to attach.

Thanks!!

Mike

Use a fishing rig under your drone in case you get hooked up.
Have seen them in PP that used them for drone fishing and wired
it to the lights. Get stuck just release it.

 

[slozukimc]

Use a fishing rig under your drone in case you get hooked up.
Have seen them in PP that used them for drone fishing and wired
it to the lights. Get stuck just release it.

Good idea. I was thinking of mounting the winch, battery and all of that on a cargo drop of some sort to release the whole assembly in an emergency.

On another note I just flew the S900 a bit. That big bird is very intimidating to fly until you realize just how precise the dji A2 flight system and a good quality Futaba radio are.

I have to get into the programming. RTH works but I don’t like not having stick control to fine tune the landing. Maybe I can fix that.

Mike

 

[cheddar-man]

Personally I don't see "strong magnet" and "drone" going very well together! The built in compass and probably the IMU are extremely sensitive to any outside magnet field influence.

 

[slozukimc]

Personally I don't see "strong magnet" and "drone" going very well together! The built in compass and probably the IMU are extremely sensitive to any outside magnet field influence.

That is what I am wondering about. If I get ready tonattach the drone and turn on the magnet is everything going to go awry in a hurry? If I hang the magnet low enough will it bother? Will it only effect gps and navigation? Can I still fly under manual control?

Mike

 

[Defens]

One small caution - be careful to not glue the washer over the GPS antenna on you test drone. Could affect GPS acquisition.

 

[eEridani]

I've had a small strobe affect compass calibration. A steel washer large enough to support lifting the victim drone may cause even more normal flight issues, especially after it has been lifted a few times and the steel gets magnetized.

 

[cheddar-man]

One small caution - be careful to not glue the washer over the GPS antenna on you test drone. Could affect GPS acquisition.

To add to this, you really don't want to be attaching any big lumps of iron onto a drone, it WILL screw the compass!!

 

[Kilrah]

Wouldn't expect the S900 to have issues as long as you make sure the winch is extended before turning the magnet on, but it's quite likely the "recovered" aircraft will be disturbed by the washer, especially after the electromagnet was attached since it'll retain some magnetism.

 

[slozukimc]

Now on to other ideas. I think a three prong snatch hook may work.

The residual magnetism in the washer is something I had not thought about but will certainly end up causing issues.

Thanks All,

Mike

 

[Capt KO]

Gannet makes a release mechanism that can be preset to release if it gets hung up… Just in case. If strain is too great, it lets go. Fully adjustable

 

[eEridani]

Find the maker of those claws in the "Catch a Teddy Bear" crane games you see at amusement parks and restaurants. They also have a release setting.

 

[MurMan]

Seems I saw a grappling hook somewhere that had 3 or 4 fingers
that stayed closed till it was sat on whatever then the weight above
the fingers opened them up to grasp whatever. And when you pulled up they closed. Seems in was in PhantomPilots way back.
I will see if I can’t find that thread.

I have one of those, 5 fingers I think, and it works well! I delivered a beer to my neighbor one day with it

 

[dirkclod]

I have one of those, 5 fingers I think, and it works well! I delivered a beer to my neighbor one day with it

I never could find the thread where I saw it. Might been you.
looked on the web also but never found what I was looking for

 

[wombat]

I also have the small version of the claw, but this may help WATCH: 'Eagle Claw' Drone Picks Up Payloads Like A Bird Of Prey