Here's a weird one

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You simply MUST put a whistler in it. Those old whistle rings that made a sort of "vooom!" buzzy whistle sound almost like a dentist drill.

I found a vid with the sound.

[video=youtube;0pNWVy-yGFg]https://www.youtube.com/watch?v=0pNWVy-yGFg[/video]
 
You simply MUST put a whistler in it. Those old whistle rings that made a sort of "vooom!" buzzy whistle sound almost like a dentist drill.

I found a vid with the sound.

[video=youtube;0pNWVy-yGFg]https://www.youtube.com/watch?v=0pNWVy-yGFg[/video]
Screamin Uni?
 
You simply MUST put a whistler in it. Those old whistle rings that made a sort of "vooom!" buzzy whistle sound almost like a dentist drill.

I found a vid with the sound.

[video=youtube;0pNWVy-yGFg]https://www.youtube.com/watch?v=0pNWVy-yGFg[/video]

If successful let me know. I have tried multiple plastic whistles including siren whistles without success
 
I certainly encourage anyone else who wants to have a go at it, though...

well I took you up on that and here she is.
"HOLYCLUSTER"
2-24mm motors, tail cone was the nose cone until I messed it up. LOL

neil's rocket 004.jpg

holycluster020.jpg holycluster017.jpg holycluster018.jpg
 
LAUNDRY??

Well that's another story,,,,,,

I'm going to try it out this weekend, with a ground test. I plan on loading it with two charge canisters with 1/2g each of BP to blow off the main nose cone w/laundry.
 
I want to ground test before flying it, just for the piece of mind it'll come out.
There really isn't much room inside for a chute to fit.
neil's rocket 006.jpg

I am looking for a way to fill in around the pod cones, any ideas would be appreciated.

020170603_101628.jpg
 
Last edited:
I plan on using these guys for the test, two empty cases with charge wells nested inside.

holycluster021.jpg
 
I want to ground test before flying it, just for the piece of mind it'll come out.
There really isn't much room inside for a chute to fit.
View attachment 321588

I am looking for a way to fill in around the pod cones, any ideas would be appreciated.

View attachment 321604

Not sure if would work, but maybe some 2 part expanding foam?
 
I want to ground test before flying it, just for the piece of mind it'll come out.
I am looking for a way to fill in around the pod cones, any ideas would be appreciated.

View attachment 321604

Card stock shrouds might take a bit of trail and error to get them right but would likely be the lightest option
 
Well I got to try out popping the laundry and it worked really well.
I used a 1/4g of BP in each pod. The rubber shock cord I have on there is a little short but the chute came out as if it was a fully empty bt-80.

I wanted to video it, but the excitement got the better of me
 
Well I got to try out popping the laundry and it worked really well.
I used a 1/4g of BP in each pod. The rubber shock cord I have on there is a little short but the chute came out as if it was a fully empty bt-80.

Cool. I'd be interested to see even a static picture of the whole laundry setup.

As for the filing the area around the pods (sorry just catching up here) it looks like you left yourself a tough chore there. My first instinct would be pieces of 3/32" balsa, sanded to fit in there. I like balsa easy sandability, vs. cardstock which I think would more challenging to cut to fit. Did you solve this yet?
 
I want to ground test before flying it, just for the piece of mind it'll come out.
There really isn't much room inside for a chute to fit.
View attachment 321588

I am looking for a way to fill in around the pod cones, any ideas would be appreciated.

View attachment 321604
Maybe an undersized cardstock piece (for lightening, support, and the approximate shape) and wood filler sculpted to the correct form?
 
I'm just now getting caught up to this one as well. Looks really cool, please more pics!
 
I'm just now getting caught up to this one as well. Looks really cool, please more pics!

I second that! :grin:

GREAT design Neil and FANTASTIC build JJSR!

For a while I had entertained the idea of some finless version of a "holey" rocket a while back, but figured it would be quite an issue to fit multiple mini rockets in the main bt and also figure out where to put recovery. The side pods and wings solves everything well in this case. My initial thought of the main tube is that it brings the CP way forward...almost like trying to toss a body tube through the air vs. one with a cone on the end. I figured spin may help stabilize an finless one (similar to the throwing rings...hmmm). I digress! Would love to see how this one flies, so please be sure to take video! :grin:

JJSR - I think balsa would be good to fill the gaps...just line up similar tubes and press down on the soft balsa, trace outline with a pen/pencil, cut, insert, glue, viola!
 
If successful let me know. I have tried multiple plastic whistles including siren whistles without success

I think the issue with whistles is that they require a lot more pressure than you normally have on a rocket, by the time there is enough, the rocket is usually too far up to hear it and the exhaust noise itself is usually louder close to the ground. I'm working on a solution (think funneling air, efficient loud whistles and RAIS), but that's a long stretch project.
 
I think the issue is that the whistles tried needed lots of air forced into them. They don't need very much air, but on a rocket the resistance from going into the whistle (compare blowing with and without the wistle in the way) makes the air go around rather than through.


If you use a whistle like a the blow hole (can't recall the proper name, if there is one) on a flute, where the air flowing past an opening makes sound, it should work better. You will need to angle the opening into the wind slightly and having a few spaced around the tube will improve the odds that one or more function.

I recall watching a documentary on some ancient group that used whistling arrows that had a ball on the tip with some angled holes carved into the side. I can't remember details but I can recall trying to figure out how to put that on a rocket.
 
Cool. I'd be interested to see even a static picture of the whole laundry setup.

As for the filing the area around the pods (sorry just catching up here) it looks like you left yourself a tough chore there. My first instinct would be pieces of 3/32" balsa, sanded to fit in there. I like balsa easy sandability, vs. cardstock which I think would more challenging to cut to fit. Did you solve this yet?


neil's rocket 009.jpg neil's rocket 008.jpg neil's rocket 007.jpg

Two anchor points on the cone one for the chute and one for the cord. Then I spiral the shock cord and shroud lines around the center tube. everything loooooossseee as can be :wink:
 
I'm just now getting caught up to this one as well. Looks really cool, please more pics!

20170527_174742 (1).jpg 20170527_234926.jpg holycluster002.jpg holycluster003.jpg
holycluster004.jpg holycluster007.jpg holycluster008.jpg 20170528_122044.jpg 20170528_191156.jpg

I had mess up the first nose cone, But it worked out as a tail cone. I seem to have not taken any pictures of the centering rings layout.

neil's rocket 004A.jpg
 
That is a different laundry deployment scheme than I had envisioned, but if it works then great (mine would have been tricky to implement in other ways). The quarter centering rings are neat.

I really like what you did with the wings and the little thingamajigs on them. The pointy tips would scare me on landings. though. :eyepop:

How big is it, by the way? I assume it's not really taller than your garage doors. :)
 
She comes in at 430 grams 37 1/4" tall, 16 3/8" X 5"

How would you have had the chute set up?
 
I tried to fill in around the pod cones with balsa 45* blocks. Found that I couldn't get them all the same without a lot of sanding.
holycluster022.jpg holycluster024.jpg

So I opted for a flat 1/8 piece and then maybe some bondo puddy
holycluster025.jpg
 
Filling the gap: I've used tissue paper mixed with (yellow/white) glue to make a stiff paste. It can easily be shaped when wet, but might shrink slightly as it dries if you glop a lot of it on (remember, these glues "cure" from the outside in).

This makes me think that a variation of this might be an untapered, plain BT-80. An uncut piece, 24 or 36 inches long, with two or three "booster pods" using rear ejection. Might need a touch of nose weight, which could be done with a wrap of solid core solder around the top lip. I've got absolutely no money to buy new parts, but I've got a supply of parts not used yet. I think I'll dig through the pile and see what I can come up with. A variation of this variation could have the pods "inset" into the bigger body tube by about half their diameter. Cutting the correct profile into this tube would be tricky, however.

Update: searched through the boxes of parts. Found a 14" piece of BT-80 - would this be long enough? Also found two matching nosecones in BT-60 (only two that matched, lots of odds and ends). The nosecones are elliptical rather than pointed (almost egg shaped). Last question: with rear ejection from a body tube this large, should I use just a plain centering ring at the top end, or should I add a (full/partial) coupler to help form more of a seal? Was also thinking of going full-blown stupid and making it either ring fin or adding an outer ring to fin tips.
 
She comes in at 430 grams 37 1/4" tall, 16 3/8" X 5"

How would you have had the chute set up?

What I had been thinking was to do it like a rear-eject. That is, have a piece up front that consisted of the inner tube, the nose cone, and a trailing centering ring. The whole thing would get pushed out, and then the chute would unwind off the center spindle.

However, this wouldn't work as I originally envisioned, because the whole thing would depressurize once the front eject portion started to move. So even if that *general* approach were to be tried, it would still need to be modified to actually work. Maybe there's no real practical way to make it work. Your way actually does work, so you win this round. :)
 
Filling the gap: I've used tissue paper mixed with (yellow/white) glue to make a stiff paste. It can easily be shaped when wet, but might shrink slightly as it dries if you glop a lot of it on (remember, these glues "cure" from the outside in).

This makes me think that a variation of this might be an untapered, plain BT-80. An uncut piece, 24 or 36 inches long, with two or three "booster pods" using rear ejection. Might need a touch of nose weight, which could be done with a wrap of solid core solder around the top lip. I've got absolutely no money to buy new parts, but I've got a supply of parts not used yet. I think I'll dig through the pile and see what I can come up with. A variation of this variation could have the pods "inset" into the bigger body tube by about half their diameter. Cutting the correct profile into this tube would be tricky, however.

Update: searched through the boxes of parts. Found a 14" piece of BT-80 - would this be long enough? Also found two matching nosecones in BT-60 (only two that matched, lots of odds and ends). The nosecones are elliptical rather than pointed (almost egg shaped). Last question: with rear ejection from a body tube this large, should I use just a plain centering ring at the top end, or should I add a (full/partial) coupler to help form more of a seal? Was also thinking of going full-blown stupid and making it either ring fin or adding an outer ring to fin tips.

I don't have any good answers to your questions, but if you do go ahead with this build please post updates here!

Given your shortie piece of BT-80 it sounds like you could make something like a goonie version? :)
 
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