TRF Summer Build Off: SSC - Spiral Spin Can

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KenECoyote

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Here's my entry for the TRF Summer Build Off Contest which Scotty started after gauging interest on a different thread (links included).

I've had an idea for a rocket that spins (to help with stability*) which I've been wanting to try and the timing seems to coincide with the TRF Summer build off, so why not? Heck, who needs sleep? :wink:

I'm aiming on creating a rocket with specially/uniquely designed fins to impart spinning (or something like that). Plus it will be modular!

*Note: rocket doesn't rely solely on spinning for stability...fins are present as well. I'm looking for spinning fins to help add additional stability for straight flight.

Updates with click links:
6/3/16 (Post #23): Mini Spiral prototype (SSC) complete
6/4/16 (Post #26): First launch of mini prototype with video!
6/11/16 (Post #62): Mini Spin Fin prototype V2 (SF2 has room between fins for rod) complete and video of launch!
6/12/16 (Post #67): 18mm SF2 complete
6/18/16 (Post #72-75): Counter-rotating fins tested on Mini SF2 as well as 18mm launches of SSC & SF2 with video!
6/19/16 (Post #91): Plastic fin can prototype built
6/20/16 (Post #92): 29mm bt w/ 38mm fin can Bearing Spin test - with video!
6/21/16 (Post #93+): Pun Wars!
7/2/16 (Post #195): 18mm versions painted with rotation recognition patterns


7/3/16 (Post #201): Launched 13mm and 18mm versions at club w/photos and some video
7/6/16 (Post #229): Started on 29mm/38mm upscale
7/14/16 (Post #238): 29mm almost done, 38mm adapter started
8/7/16 (Post #262): 29mm maiden with straight fin can - with video (post 264)!
8/7/16 (Post #270): 29mm with spin can flight - with video!


Unfortunately I misunderstood the deadline and thought I had one more launch to test the 38mm version, but no worries...I'll be continuing this build and will finish the 38mm spin and spiral cans and eventually also have on-board video! This is one of the most rewarding rocket projects I've done and will likely continue to grow (thinking of making that "VTOL" for next year!), so I don't think this one would've really had an end in sight. :)

This build has grown well beyond my initial idea and I can't thank Scotty and the others enough for organizing and supporting this contest. Also much thanks to the other TRFers for their support and help!
:clap::clap::clap::clap::clap::clap::clap::clap::clap::clap::clap::clap::clap:
 
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KenECoyote

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5/30/16 Update:

(Moved this section down to allow room for updates in post #1)

Still thinking of names, but since my daughter really likes the "Yokai Watch" cartoon, I'll throw this in for now:



I'll update as design and build progresses.

5/31/16 Update:


Okay, I found some time today (that was quick, huh?) and here are some shots of my design and build...a spiral finned rocket - almost like a "drill fin". Not sure if this has been done before, but I couldn't find it after a few searches.

Bear with me since I'm making decisions as I proceed, so my first build can be the final or possibly a first prototype before up-scaling.

Here's a temporary paper fin to show the idea:


When I first tried this, I figured I'd just estimate the curve needed on the fin. I got it pretty darn close with trial and error (and luck), but figured there is some formula for this. I did a bit of research and found some possible calculations to use and it's related to trigonometry.

Here's a shot of some sketching while I was trying to figure it out:



Basically I'm trying to determine the radius of a curve drawn diagonally across a tube, which translates into part of a giant circle (or helix)...simple, right? :wink:

6/1/16 Update:

After a bit of research, I figured I'll put that part on the back burner since my first template seemed pretty darn good. I'll revisit this piece if I upscale.Next I took the paper template, traced it onto heavy cardstock, cut them out and glued them on with wood glue...viola! :grin:



BTW - still figuring on launch lugs, but I think I have it figured out. Also this one is currently modular, but I may have to abandon that due to the launch lug plan...we'll see.
 
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RocketFeller

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I like it! I built a conventional spinning rocket (canted fins) a few weeks ago that is fun to fly. Yours looks amazing.
 

BABAR

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Cool concept.
Idea for launch lug
Go three engine cluster (can even use mini motors) and run a small tube up the middle between engines, cut tip of nose cone just big enough for 1/8" rod
Run launch rod up the middle of the rocket
 

gerbs4me

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Very cool design
I'd like to see a video of the launch, would be really cool to see.
 

KenECoyote

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Thanks All for the compliments! :)

I like it! I built a conventional spinning rocket (canted fins) a few weeks ago that is fun to fly. Yours looks amazing.
I missed that thread, but just found it...really cool!

Cool concept.
Idea for launch lug
Go three engine cluster (can even use mini motors) and run a small tube up the middle between engines, cut tip of nose cone just big enough for 1/8" rod
Run launch rod up the middle of the rocket
WOW! I think that would be AWESOME, however I haven't done clusters yet (on my to-do list), but may consider after upscaling. Also a problem with the rod up the middle is handling of the chute (streamer would be less problematic though).

Very cool design
I'd like to see a video of the launch, would be really cool to see.
I won't have a chance to launch it until the weekend, but I'll be sure to video for everyone's amusement! :grin:
 

KenECoyote

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Here's a surprise feature...

[video=youtube;pEJTBJDw-C4]https://www.youtube.com/watch?v=pEJTBJDw-C4&feature=youtu.be[/video]

This is literally a rocket with "spin fins". :wink:

The way I have this designed, I'll be able to test it first spinning and then not spinning to see the difference. I plan on later (on a different build) possibly making a version with spinning propeller base, so this is a good test.

I hope it has that cool "drill"/"buzz" sound when it launches! :grin:
 
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Amsterdam

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Very cool!
Off topic but Would it be possible or I guess viable to mount a small "canard" version of the drill fin on your finless experiments to reduce the need for nose weight? Similar to what Micromeister is doing here
something like bt20 airframe and nose, a few inches of drill fin riding on a bt5, then on down with the rest of your finless design.
 

KenECoyote

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Very cool!
Off topic but Would it be possible or I guess viable to mount a small "canard" version of the drill fin on your finless experiments to reduce the need for nose weight? Similar to what Micromeister is doing here
something like bt20 airframe and nose, a few inches of drill fin riding on a bt5, then on down with the rest of your finless design.
Thanks!

It would be possible to have an additional spinning canard on a finless model; however forward canards bring CP way forward, which is bad mojo when there aren't fins in the back to bring it back. How about in internal turbine in a finless rocket so that it acts like a gyroscope? I like that one! Would probably sound wicked on the way up too! :grin:

I did consider a forward spinning prop/angled fin collar/canard for a different "VTOL" project which I may do one day. In that case it has a large propeller on the bottom and a cockpit in the body, so I'd possibly want a smaller counter-rotating canard at the front to help prevent the body from spinning.
 

Daddyisabar

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Seeing it spin reminded of a song I played for Mom as a youngster on the piano:

The Windmills Of Your Mind

Written by Alan Bergman, Michel Jean Legrand,
Lyrics


The Windmills Of Your Mind

Round like a circle in a spiral, like a wheel within a wheel
Never ending or beginning on an ever-spinning reel
Like a snowball down a mountain, or a carnival balloon
Like a carousel that's turning running rings around the moon
Like a clock whose hands are sweeping past the minutes on its face
And the world is like an apple whirling silently in space
Like the circles that you find in the windmills of your mind

Like a tunnel that you follow to a tunnel of its own
Down a hollow to a cavern where the sun has never shone
Like a door that keeps revolving in a half-forgotten dream
Like the ripples from a pebble someone tosses in a stream
Like a clock whose hands are sweeping past the minutes on its face
And the world is like an apple whirling silently in space
Like the circles that you find in the windmills of your mind

Keys that jingle in your pocket, words that jangle in your head
Why did summer go so quickly?
Was it something that you said?
Lovers walk along a shore and leave their footprints in the sand
Was the sound of distant drumming Just the fingers of your hand?

Pictures hanging in a hallway and the fragment of a song
Half-remembered names and faces, but to whom do they belong?
When you knew that it was over were you suddenly aware
That the autumn leaves were turning to the colour of her hair!
Like a circle in a spiral, like a wheel within a wheel
Never ending or beginning on an ever-spinning reel
As the images unwind
Like the circles that you find in the windmills of your mind
 

REK

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Man that is going to be awesome. Already getting ideas for a high powered one lol.
 

REK

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Oh and I'm subscribed, looking forward to the flight :).
 

KenECoyote

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Man that is going to be awesome. Already getting ideas for a high powered one lol.
Thanks! Also I had the same idea and was actually going over some bigger tubes this morning. :tongue:

Something about this one also looks dangerous...so that means I should upscale, right? :wink:
 

Gary Byrum

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BTW - still figuring on launch lugs, but I think I have it figured out.
My guess is, it's going to spin so fast, there won't be a lot of altitude. Which may or may not really matter. Still looks pretty cool. Have you considered launching it from a tube? Maybe a LL won't be necessary.
 

KenECoyote

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My guess is, it's going to spin so fast, there won't be a lot of altitude. Which may or may not really matter. Still looks pretty cool. Have you considered launching it from a tube? Maybe a LL won't be necessary.
Yup, I'd guess the same. Canted fins = drag (even when spinning)...still, I figure if there is a cool sound from the spinning fins, it may make up for the low altitude (which I don't really care about given my launches are best kept in smaller landing areas and I prefer to see the rocket).

Regarding the LL (launch lugs), I'm first going to use two Estes mini collars that have a LL molded on (like on the Gnome) and put a hole through the fin(s). I thought of using a launch tube, but decided against that since it complicates things and likely would dirty the rocket. Also buttons are out of the question on this unless I use fly away guides (maybe for upscale...hmmm).
 
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Gary Byrum

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Regarding the LL (launch lugs), I'm first going to use two Estes mini collars that have a LL molded on (like on the Gnome) and put a hole through the fin(s).
If you're considering all of that, you might as well run a lug all the way up the side of the airframe and make the necessary cut-outs on the fins to go over it. That rocket's only going to be on the pad for a micro second anyway. At least it'll be strong on the rod and you can fill any gaps in the fins where they embrace the LL. It'll also make for a really clean look. My reasoning on this is simple. With all that effort to try and spin off the rod at liftoff, one of your collars could break loose and it's back to the drawing board toting a broken rocket. This is one time where a little overkill could really save the day.
 

rstaff3

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I think I mentioned that, based on my screw fin rocket, I would go with a tube launcher. Really easy and I haven't noticed any damage. Here I mean just a piece of PVC. I have never used a piston launcher but I'm sure that isn't too hard.

Having built a lot of spinning rockets, they generally don't seem spin on the rod. if not going with a tube launcher, I would make holes in the fins and let them to some extent act as a lug. maybe one actual lug at the bottom.

As mentioned above, this will not be a great performer. But it will sound cool :)
 

KenECoyote

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If you're considering all of that, you might as well run a lug all the way up the side of the airframe and make the necessary cut-outs on the fins to go over it. That rocket's only going to be on the pad for a micro second anyway. At least it'll be strong on the rod and you can fill any gaps in the fins where they embrace the LL. It'll also make for a really clean look. My reasoning on this is simple. With all that effort to try and spin off the rod at liftoff, one of your collars could break loose and it's back to the drawing board toting a broken rocket. This is one time where a little overkill could really save the day.
Good idea; however a lug all the way up on one side would cause more weight as well as drag on just one side and for something meant to rotate, that would be bad mojo. The collars I'm referring to are mucho strong, and the rocket will break before them, so no worries there.

I think I mentioned that, based on my screw fin rocket, I would go with a tube launcher. Really easy and I haven't noticed any damage. Here I mean just a piece of PVC. I have never used a piston launcher but I'm sure that isn't too hard.

Having built a lot of spinning rockets, they generally don't seem spin on the rod. if not going with a tube launcher, I would make holes in the fins and let them to some extent act as a lug. maybe one actual lug at the bottom.

As mentioned above, this will not be a great performer. But it will sound cool :)
Good food for thought! I hadn't had experience with tube launching, so that's good to know. Still, I'd prefer KISS and just have the rocket to take up to the pad. Maybe the next version I'll make with fins flat on the bottom edge so they fit into a tube launcher better...hmmm...sounds like it can be even more dangerous! ;)

Also like the idea of multiple holes up the fin and using that alone. If it was 2-3 fin sections in line vertically, it would probably be good for it, but it's one and maybe the tip of another (I made it so that fin twists up over a 1/3 section of the tube).

I'll try to post pics of the lug collars arrangement soon so you guys can see what I'm talking about.
 

KenECoyote

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BTW - I've launched some custom design spinning mini rockets on A10-3Ts this year (however not this design..much more different) and they can get impressive enough height. Being mini, I don't know if I'd like it to get any higher since you can't see them very well past a few hundred feet and then finding them can be difficult if they arch/angle over in flight.
 

KenECoyote

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Here's a pic showing how the collars would be used. The hole through the fin is larger than I would've liked (in fact, I have to make it yet larger), but it does the job.

 

rstaff3

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That looks good to me. Maybe treat that section of the holey fin with CA and make sure it is well attached.
 

KenECoyote

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That looks good to me. Maybe treat that section of the holey fin with CA and make sure it is well attached.
Great minds think alike! :) Yup, I was planning on that earlier since the cardstock by itself would be too soft there and likely to tear. I brushed CA on over the area and it strengthened and stiffened it up a lot.
 

KenECoyote

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Okey Dokey...I got to launch this today...

First locally on a 1/2A3-2T with a 13g weighted nose (I didn't want to take any chances and will lighten the nose as I run more flights). Very straight and fast! I didn't hear any buzz, but I guess that's due to the motor being louder (hmmm...maybe a little plastic strip on the bottom to make a buzzing noisemaker like kids used to do on bike spokes with a baseball card..hmmm). Still an Excellent flight in my book!
[video=youtube;jWbjRmARxko]https://www.youtube.com/watch?v=jWbjRmARxko[/video]
I didn't notice until later that part of the front of the body tube got a bit crushed...I hadn't seen similar before, so it was a surprise (maybe nose sprang back to hit the tube edge and pushed it downwards and inwards). I thought I could straighten it out, but it was very humid out and this made the tubing a bit squishy after trying to reform it back, so it didn't look good. Luckily I had made this somewhat modular, so I just pulled everything off and put it onto another rocket main motor tube (one painted black) which I had prepared earlier for a different launch...

Next I launched it at my rocket club off an A10-3T...I love this little motor since it's like a micro Vmax! Launch was laser straight almost out of sight and the crowd loved it. Got lots of compliments from a group used to many HP flights (including I believe a few M flights today):
[video=youtube;01FVKnwQbiM]https://www.youtube.com/watch?v=01FVKnwQbiM&feature=youtu.be[/video]

I'll likely next make another fin can with a small space between the spiral fins so the rod can go between them and then skip the holey fin. Then maybe a 24mm/29mm upscale and I'll paint it in a way so I can see how the fins spin as well as the body. I'm also entertaining the thought of upper and lower counter-rotating spiral fins to see how that goes and if it makes any sound (backburner project).

I love how straight and fast this rocket goes...also quite high!
 
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Amsterdam

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Success! Very nice. It looks so surreal to me. Like a cartoon or something. In a very good way of course.
 
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