Siren/Screamer Protection

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dvdsnyd

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Hi,
I flew a defense safety siren/screamer yesterday to aid in locating the rocket. It was attached to the harness and devised in a way that once the harness went taught, the pin would be pulled activating the siren for all to hear. The one I am using can be seen in the link below:

Link to siren


I ground tested this arrangement twice and it worked perfectly both times, deploying the siren perfectly.
However, the first flight did not go to plan.
The siren was deployed and was on when I came up to the rocket, although the sound emitting from it was not the usually loud and obnoxious alarm, but a faint electronic gurgling sound, that could only be heard once almost on top of it.

I inserted the pin and activated it again, same thing - faint gurgling. After a few more times of this, the alarm suddenly came back to life, working as advertised.
I haven't been able to replicate the weird behavior since.

I'm wondering if anyone else has experienced this? How are you protecting the alarm? In my arrangement, the alarm is within fairly close proximity of the ejection charge. I wonder if the charge messed with the piezo buzzers some how? Appreciate everyone's insight!

Dave
 
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rocketgeek101

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I make sure the alarm is situated above the parachute protector, but attached the the shock-cord below the parachute. When I prep the rocket, I have the portion of the shock-cord with the alarm attached loop up above the parachute bundle. Haven't had any issues with this method.
 

dvdsnyd

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Good thoughts!
Unfortunately, with my current configuration, I'm unable to have the siren above the parachute bundle.
I think I will try adding a chute protector for the siren in the next flight.
 

Handeman

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Maybe I'm cynical, but if you turned it on and off and it worked again after 2 or 3 tries, I think it's a quality control think with the siren. You get what you pay for in most cases and this might be something you might want to spend a little more money on, especially if personal safety is really at risk, IMHO
 

dvdsnyd

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Maybe I'm cynical, but if you turned it on and off and it worked again after 2 or 3 tries, I think it's a quality control think with the siren. You get what you pay for in most cases and this might be something you might want to spend a little more money on, especially if personal safety is really at risk, IMHO
I'm not sure what you mean by your last sentence, this has nothing to do with my personal safety.

The reason for the siren in the rocket is to aid in locating it. I have an Eggfinder GPS system onboard, but in the Midwest corn and soybeans become problematic by July/August. The idea is that the GPS can get close, but the siren will allow the rocket to be located easier. given the GPS doesn't always lead you right to it because with the Eggfinder GPS LCD it refreshes every 10 seconds and only if you've traveled 30 ft or more in that time. Sometimes this isn't possible when trenching through corn or beans.

I don't think there is an issue with the siren itself. It goes off every time under normal conditions, however, I'm subjecting it to an ejection charge, which admittedly may be the problem, since it worked perfectly before that. Looking for experience from others on mitigating the same result.

Thanks,
Dave
 

Handeman

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I'm not sure what you mean by your last sentence, this has nothing to do with my personal safety.

Thanks,
Dave
All I was saying is, this is a personal safety device that you are using in a way it wasn't designed for. If it doesn't work the way you are using it, I'm not sure I would trust it for it's intended purpose either.
 

neil_w

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I flew a defense safety siren/screamer yesterday to aid in locating the rocket. It was attached to the harness and devised in a way that once the harness went taught, the pin would be pulled activating the siren for all to hear.
Can you show what that arrangement looked like?

I keep thinking I should get some screamers but keep procrastinating. Would love to be able to take commodity items from Amazon etc. and rig them up in a reasonable way. Thinking maybe take the circuit board out of the package (if possible) to make it smaller and lighter.

Anyway, interested to see what you came up with.
 

dvdsnyd

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Can you show what that arrangement looked like?

I keep thinking I should get some screamers but keep procrastinating. Would love to be able to take commodity items from Amazon etc. and rig them up in a reasonable way. Thinking maybe take the circuit board out of the package (if possible) to make it smaller and lighter.

Anyway, interested to see what you came up with.
Neil,
This is how I have it configured.
This particular device splits in half and allows the attachment of a small kevlar loop to the back end(bottom in the pic below)
The pin is ground down( top of the device) to promote easier separation from the device which activates the siren.
The device is mounted between a longer loop of harness. When the harness goes taught, the pin is pulled activating the siren.
Worked well in my testing, and deployed on launch day. Just an issue with the screamer, which I'm assuming is related to the ejection.

IMG-2058.jpg
 
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