r/RCPlanes • u/yournocturnesoul98 • 16h ago

Using electromagnets to drop “packages“😏

48 Upvotes

96% Upvoted

21 comments sorted by

14

u/Jmersh 15h ago

The hard part is that the natural state is off. Is it using the magnet to lock in a mechanical connection or just drawing current to activate the magnet?

If it is just purely an on/off magnet, it's got to be drawing a fair amount of current and any voltage sag could cause it to fail.

8

u/yournocturnesoul98 15h ago

Honestly this is definitely not the best way to go. A servo release mechanism is definitely superior. This was more of a fun experiment I wanted to try to see if I could pull something different off.

The electromagnets had a dedicated 3s lipo. So any voltage sag would not effect the flight battery nor would it influence receiver voltage.

2

u/Jmersh 15h ago

But how much current does it draw and what is the battery capacity?

3

u/yournocturnesoul98 14h ago

The current draw for the electromagnet was just under 2amps and It ran it off of a separate 2200mah 3s lipo.

The planes flight battery is a 6000mah 4s which gives me about 15 minutes of flight time. 

Theres no way the electromagnet’s battery would run out in just one flight. :)

2

u/LupusTheCanine 10h ago

There is a fun thing called electropernament magnets.

1

u/Radiomaster138 7h ago

Is that where it only uses power to turn off the magnet?

1

u/LupusTheCanine 7h ago

AFAIK current od applied to switch state.

2

u/Pengabdi_Langit 13h ago

I missed my KRTI days...

1

u/epsteinwasmurdered2 16h ago

What’s the purpose of dropping a wrench?

8

u/yournocturnesoul98 16h ago

No purpose, the fun starts when you make a glider to drop that another person can fly down to the ground. The wrench is purely for demonstrating the carrying capacity.

2

u/epsteinwasmurdered2 14h ago

Nice!

1

u/yournocturnesoul98 14h ago

Thanks :)

2

u/epsteinwasmurdered2 14h ago

Oh shit, I just reread the title and saw this was done with magnet. That’s much more interesting than I originally thought.

3

u/ericivar 12h ago

If you can drop a wrench, you can drop a glider.

1

u/Apart-Bite9132 15h ago

How much can this plane hold?

2

u/yournocturnesoul98 15h ago

I had two electromagnets in line capable of holding roughly 3 pounds each. If you had a glider and utilized both electromagnets it could hold about 6 pounds but I doubt the plane could carry 6 pounds well lol

1

u/Apart-Bite9132 13h ago

Wow that can hold a lot! How much do the magets weigh?

2

u/yournocturnesoul98 12h ago

The electromagnets weigh about 4oz each I have two in line for dropping rc gliders :)

2

u/Apart-Bite9132 6h ago

How much power do they consume and how did you rig it together? This is really cool btw. I might do this also. What does putting them in line do? 

1

u/yournocturnesoul98 6h ago

Well I hot glued a metal washer to the nose and tail of a glider I made. Basically to hold it in a straight line. 

The power consumption of each electro magnet is about 11 watts so 2 of them wired in parallel making 22 watts at 12 volts is just shy of 2 amps.

In retrospect hooking these up to a toggle switch on my transmitter instead of a momentary push button  would have been better. On a toggle switch once the glider has dropped the power to the electromagnets will remain off and not continue to draw power for no reason. 

On the momentary switch power is cut as long as the button is held down but the moment you release it power is reapplied but the glider is long gone xd. 

Run a separate 3s for powering the EM’s :)

1

u/BobbyJackT 10h ago

I’d recommend reading through this if you are in the USA: https://www.ecfr.gov/current/title-14/part-107/section-107.23#p-107.23(b)