LOC Athena3 Build, 3.1" 29mm - Whistler

Awesome whistle!

Great whistle! My 4" Madcow bateau whistled pretty good too but not quite as loud as yours.
I am trying to induce a whistle in my L3 build without a split fin via air intakes and shape air exhaust holes, but won't know until it flies.

Nick@JET said:

Great whistle! My 4" Madcow bateau whistled pretty good too but not quite as loud as yours.
I am trying to induce a whistle in my L3 build without a split fin via air intakes and shape air exhaust holes, but won't know until it flies.

Click to expand...

Ha, it would be uber cool to have some surface mount whistles like are on a nerf football.

On the idea pile: train whistle nosecone.

I made a short video from GoPro footage taken near the base of the launch pad. Hindsight says I should have used a maximum field of view setting on the GoPro. Rather, I had the GoPro set to Narrow FOV and 60 fps. The flight was perfect. The H250G snapped it off the pad at 20 G's, and then the Athena whistled all the way up to apogee. The StratologgerCF fired the drogue charge nicely at apogee, and the 1.1 g charge had plenty of punch to extend the payload to full shock cord extension perfectly straight out from the booster. The small 9" drogue allowed it to come down relatively fast, minimizing drift in the stiff winds that were plaguing the launch. I should have set the main charge to a lower altitude, as when the main deployed at 700' AGL, it was obvious that the rocket was going to drift a long way. The stiff winds were easily pushing close to 20 mph on the surface. My wife and I took a careful bearing between two points to make certain we would walk the correct line to intersect the rocket. Unfortunately, it landed in some > knee high vegetation/crop that would hide it from view. Fortunately, the amplified beeper was easy to hear from roughly 100 feet away and we were guided to the rocket, which was about 30 feet to the side of the line we were walking.

Here's a link to the video:

[video=youtube;wjfBN2rkIRc]https://www.youtube.com/watch?v=wjfBN2rkIRc[/video]

Here's the stratologgerCF data:


I still need to finish adding the metallic pink paint down the body and on the fins... a lot of masking work for sure.. but if I ever get around to it, my daughter thinks it will look excellent.

The Athena3 had a nice flight yesterday at Snow Ranch, CA. I tried out an Aerotech RMS 29/240 H210R-M reload. It was on par with the H250G in performance, although the light winds yesterday gave it an advantage over the 3 windy day flights I've had with the H250G's. The Red flame burned out low enough that the whistle of the Athena was very pronounced. I have a ground based video that I'll share soon.

While it was a nice flight, two things went wrong:
1. The motor ejection fired too early. I was supposed to be a 10 second delay.
2. The motor ejection was a bit too potent at 1.2g 4F.. and it thrust the payload tube out a bit too fast and when the 20 ft shock cord snapped tight, the nosecone came off and the main parchute deployed near apogee. Fortunately the winds were nill.. and the rocket landed close by.

I'm considering either tighter tape or going with 2-56 shear pins on the nosecone. The tape worked fine for 3 of 4 flights so far. I could also tune down the motor ejection charge to say 1.0 g 4F.

Here's the StratologgerCF data plot:


On the pad, ready to go:



Under the main chute, nice and close:

Full Version:
[video=youtube;PdXn5p3kvD8]https://www.youtube.com/watch?v=PdXn5p3kvD8[/video]



Short Version:
[video=youtube;MYW8_rvTguo]https://www.youtube.com/watch?v=MYW8_rvTguo[/video]

The Atehna3 DD flew yesterday with an Aerotech RMS29/360 I200W-L. I drilled the delay from 14 seconds to 12 seconds, which worked nicely as a backup charge for the drogue deployment. The flight was straight up and impressive. The I200W, however, has a rather wide nozzle that created a wide plume of white lightning flame a bit too close to the aft of the rocket and fins. The paint took a little heat damage during the 1.5 second burn... but is still covering the bare wood.
The StratologgerCF shows that it reached 2,641 ft at apogee, and that it fired the drogue nicely at apogee and main at 500'. I was planning to attach the plot from the Stratologger, but there seems to be a problem uploading files right now. I'll try to upload it again later today.

Off the pad quickly with a nice I200W White Lightning Exhaust Plume:


Dual Deployment, Descent under the stock LOC Main Parachute:


Thanks to SCRocketfan for the excellent flight photos!


Finally, the stratologger data to 2641 ft:

I love this rocket!!! This was the old Yank "Mystic Buzz". We named it simply for the fin whistle! Thanks for sharing!

The Athena 3 DD flew last weeked at Snow Ranch on an Aerotech RMS 29/240 H220T-M. It was a nice flight to 1,500 FT.
Here's the StratoLoggerCF Plot:



Also, Woferry posted a very nice video of the flight here:

https://photos.google.com/share/AF1...?key=Zk85VUFlaGxIWUQwNVNNblZfRUU0TkVkNWdWSjNR

The Athena3 DD flew at Saturday's TCC launch in Helm, CA on a full H motor, the Aerotech RMS 29/360 H268R-14A. This boosted the rocket to 2,550 Ft, with a maximum velocity of ~540 ft/sec. A little less altitude, but more velocity than the I200W flight. These are in good agreement with my Open Rocket simulation model.
I didn't bother drilling the delay as I've had too many of these 29mm reloads motor ejections fire early.
I also reduced the altimeter's drogue charge to 0.7g 4F and the motor backup drogue charge to 1.0g 4F. I did this in an effort to reduce internal pressure during drogue deployment, which will hopefully prevent the StratologgerCF Amplified Buzzer from being damaged again. (I've had 3 of them fail on this rocket already!).
I kept the altimeter's main parachute charge at 1.0g 4F since I've been making rather tight friction fits to prevent the nosecone from coming off during the shock from apogee ejection.

The flight was perfect.. straight up with a very high frequency whistle. The frequency is likely related to velocity, which was higher given this full H reload. Both the I200W and H268R flights had much higher frequency whistles. As the rocket slowed down, I could hear the frequency dropping.. however the rocket was getting too high/far away to hear well. For this reason, I like the 240 N-sec reloads better in this rocket. I have yet to try the lesser H reloads, the 180 N-sec variants. I suspect they will yield a lower frequency whistle.. and I hope it's even more audible that the whistle when flying the 240 N-sec reloads.

Here's what the StratologgerCF recorded for altitude:

The Athena 3 flew again last weekend at Tripoli Central California's October Skies 3 day launch event.
The boost was very nice as expected, hard hitting to get the velocity up fast, then burnout silence from the motor, allowing the signature whistle to be heard all the way near apogee.
I could see it from the ground that the motor ejection was too early again and the Athena's ascent was abruptly decelerated from 100 ft/sec up to 0 in an instant. Fortunately, the small drogue didn't decelerate things too abruptly and there was no damage or zipper to the rocket. For this flight, I had switched out the 9 in drogue to a 12 in drogue to try to get the booster to fall under the canopy for the whole flight. Even with the 12 inch drogue, the booster was still spinning and drifting up near the drogue. The booster is pretty light with a good amount of fin surface area to catch the wind while falling. When the main fired at 500 ft, the parachute opened right under the shock cord and the chute was folded in half right down the middle by the cord. The system fell relatively slowly to the ground. The descent rate didn't change under the main, but fortunately, the booster aligned straight down below the folded parachute such that the motor retainer and base of the booster tube (which I reinforced with 2 short layers of fiberglass) hit the ground first, taking a moderate blow. Then the payload and nosecone fell much more slowly under the folded parachute without damage. I inspected the booster and fins when I picked up the rocket, and there was no damage at all, not even a ding in the base of the fins.
Here's the data plot from the StratoLoggerCF.. obvious early motor ejection, roughly 3.5 seconds too early.