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The old bottle drop mechanism was fairly dodgy so I have re-vamped it.

This is tricker than it looks as the water bottle weighs greater than 500g which is a significant part of the aircrafts weight and mounting such a mass directly over the center of gravity difficult.

I wanted the simplest mechanism possible to hopefully avoid breakdowns so I went for a single lock-pin design see pictures below.


The water bottle mounting plate, I used cable ties to secure the bottle as the bottle flexes considerably.



The water bottle in the payload bay of the UAV.




A plate with a servo was secured above the water bottle in the payload bay.




I am using a high torque servo to move the lock-pin into position.





This shows the lock-pin the the release position and the water bottle is now free to fall from the bottom of the aircraft.


The green mounting plates are last years system that was pretty much a modified toy I got off Hobbyking, needless to say it worked once and then broke. See last years D2 video below.


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I am using a small parachute to slow the bottle's decent. The parachute is connected to the bottle via a heavy duty fishing swivel that is cable tied around the neck of the bottle.


The parachute is an "X-Style" from the world of model rockets. The theory is that the X-shape makes it less susceptible to being carried away by cross winds. 


The parachute is rolled up and tucked away in a small space behind the bottle in the payload bay.


The bottle is then loaded into the lock-pin mechanism ready to be dropped.


Center of gravity test before and after bottle drop (after shown). It was slightly more nose heavy after the drop so I will have to do some tweaking before the weekend. 

Tagged in: servo , Lock-Pin , Bottle Drop