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Self Opening Clip with time delay of 2-3 mins Answered

Hi All

This is my first post, so I apologise in advance if I've selected the wrong category for the post.

I have an idea... I have a quad-copter at home that I'd like to attach a small light weight item and have it self release/open after 2-3mins. Ideally, either a small springloaded clip based on the rough image below or something similar, that is self opening after a selected timeframe, even after 1-2mins, or alternatively, a small lightweight mechanism that does the same thing. I've searched everywhere and can't find anything even close; lots of small clips, hook, latches, but nothing that 'self-opens', which is the most important spec.

I can add a new RC servo and swinging arm and operate the release by remote, but I want to avoid it if there's a simple solution out there.

Appreciate any help if someone has seen something out there?

Discussions

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Toga_Dan

4 years ago

Are you trying to avoid the weight of an extra servo and circuit? The expense? The effort?

Depending on what you are trying to release, you might look at mechanisms like those on ancient crossbows, catapults, and modern mousetraps. Basically something that uses a small force to control a larger force.

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Toga_Dan

4 years ago

Similar idea to downunder35m's idea:

sugar used as glue. add water, fly, wait for it to disolve. How long it takes will be a matter of guesswork.

Sugar cube probably dissolves pretty fast.

hard candy? maaaaybe. There's probably an instructable on making it.

Cotton candy string? Probably immediate release. Is there a way to delay releasing water onto it?

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another idea: hot glue and heating element. This was somethin I accidentally "invented" while doing rockets. After hot glueing fins to a rocket, the rocket flew straight, but the fins came off (or just got loose) while returning to earth.

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What are you trying to drop? eggs? anvils? a camera?

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Downunder35m

4 years ago

Obviously the best option would be a proper remote with a free channel and a servo to operate the clip.

Depending on the temperatur an ice cube might work well.

(or a smaller piece of ice, depending on the weight)

In the most simple form just a rod made from ice that is in a holder and a string holding whatever you want to drop.

Diameter of the ice, thickness of the string and attached weight determine how long it takes to release.

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potterboyDownunder35m

Reply 4 years ago

Thanks Downunder35m, very clever option. If anyone else has some ideas, that'd be great?

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Downunder35mpotterboy

Reply 4 years ago

If you ave the room for some electronics....
Use a simple timer, maybe just based on the NE555, and a transistor on the output to drive a tiny pull-relais.

If in doubt you can wind one yourself with some thin magnet wire and a pen or substitute a little relay where you remove the core and replace it with a stell push-pull-rod (mail or similar).
Activate the timer and after the set time the relay will pull the pin and release the load.

If you are mechanically minded you can get it quite tiny and light.
Power comes from the onboard supply for the copter.
Since the NE555 works fine from about 4-12V you should have no problems.
Documentation for the 555 is near perfect so finding the right circuit is no problem.