Building a RC airplane sequential bomb drop controller.... I think.

[scrumgees]

I haven't any experience with this sort of thing, not even enough to know where to get a good book or what a good bool even looks like in this hobby.

Anyways what I would eventually like to build is a controller that I could plug in multiple micro linear servos or micro solonoids to drop little paratroopers or dummy bombs onto targets. The catch is that I would like to be able to avtivate all bombs using one single channel on my transmitter but I dont want them to all drop at once. I would like to have it set up so that when I push the button once, it drops the first bomb. When I push the button again, it will move on to the next servo dropping the next one in line so I can drop as many, or as few as I want, whenever I want using that one channel on my reciever and transmitter.

Any ideas, or places so I can start learning about how all this type of stuff works so I can get started?

 

[Diver300]

You could use a mechanical ratchet, so that a turning one servo forwards and then backwards launches one object.

If you want to do it electronically with one channel running many servos one at a time, you need to programme a microcontroller. It needs one pin for the input from the receiver channel, and one pin for each output. Plus power pins, of course.

It could be that someone has already done this and a commercial device is available. A microcontroller will cost nearly nothing but will take time to write the program.

It could be done with logic gates but it would be huge and hell to make.

 

[scrumgees]

Ya I thought about using a ratcheting type mechanism but that seemed like a lot of extra small parts but I guess then I wouldnt have to learn to build an R2D2 first to do it electronically. I was hoping there would be some type of analog circuit maybe so i could just build it from parts without programming it.

And I shouldnt say I havent any experience with electronics. I have wired several veichles for drag racing so I understand how a relays and solonoids or rectification work but know where the level of understanding required to make this thing.

 

[HarveyH42]

I'm sure it's been done before, and there is likely something available. Remember seeing a video, maybe couple of years back, of a guy launching bottle rockets from his plane...

 

[Boncuk]

I dropped bombs from a model plane using that method:

To keep the circuit small I used a maximum of 9 bombs being triggered by a servo with a micro switch providing the clock signal for a decimal counter (CD4017). The outputs of the counter were wired to small pull solenoids being controlled by low power transistors.

The bomb was released when the solenoid pulled in.

To use more than 9 bombs you could cascade decimal counters.

Here is a sketch containing the construction details of my bombs and a circuit to release the bombs. The bombs were made of CO2-cylinders.

If you will use the same kind of bombs (making noise and smoke) don't forget to drill four 8mm holes into the cylinder. Otherwise the bomb will turn out as a real bomb!

Hint: To make sure the counter is in RESET condition you might connect a low current LED to pin3 (Q0) via a 1.5K resistor. Otherwise you might drop a bomb before take-off. (see 2nd board design)

Boncuk