A quick winter build: Odd'l Cyclone

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neil_w

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While the finishing job on the Diamond Cutter plods towards completion, I wanted to get something else accomplished. So I pulled out one of my Black Friday purchases: the Odd'l Cyclone, which I thought was perfect for winter because no painting. Woohoo!

I also decided recently that I need a few odd-rocs to spice things up at my launches, and ones which could work in a small field would be good. We'll see about how well this one works in a small field; I'll certainly try it first on a big one and see how far it drifts.

Anyway, this should be (for me) a quick build thread, but it's a cool little kit and I thought maybe others would find it interesting. I'm really looking forward to flying it, which should happen at the first spring launch I can attend.

This rocket is small and light, and that is reflected in the packaging. Here are the parts:
ImageUploadedByRocketry Forum1452388153.615626.jpg

I was initially taken aback by the very long 1/16" balsa fins, which seem as if they might break if you look at them the wrong way. After working on larger and sturdier kits, it took me a few minutes to mentally adjust to handling the comparatively small and delicate parts here.

As expected parts are of high quality and everything is nicely kitted. The instructions are clear and well organized.
 
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Three centering rings and a hook are affixed to the motor mount tube without incident. One mildly odd thing is that the instructions direct you to make three marks on the tube for them, but the first two rings are simply butted together and aligned with the top of the tube, so two of those marks were not necessary. No biggie.

Then it is necessary to peel some layers off the two top rings to enable a coupler to fit over it. This was not as quick and easy as I expected, as the layers of the centering rings did not always come off in clean pieces. Also I needed to be a bit careful to keep the two rings as much the same as possible.
ImageUploadedByRocketry Forum1452388168.404259.jpg

Eventually, success, and the coupler was glued on. I used Elmers Glue-all for this in hopes of not having the coupler seize while being applied.
ImageUploadedByRocketry Forum1452388180.334205.jpg
 
The motor mount is not installed into a short piece of BT20 that serves as the lower body tube, on which two of the three fins are mounted. A dry fit showed that it was a bit tight but seemed OK. I applied some Glue-all to the coupler and slid on the BT20 slowly but steadily. The goal is to have the tube go 1/8" passed the end of the motor mount tube. I wanted to make sure I didn't stop moving because I thought there was a good chance it would seize if I did. So I pushed and pushed... and then, just as I got close to the 1/8" point, for some reason it eased up a bit and I pushed it passed the target, to where the motor mount was protruding about 1/4". After uttering a few choice words, I tried to push it back, but of course now it had seized up, and was not going anywhere.

So my motor mount sticks out a bit too far. So it shall be!

Also: because this rocket will not be painted, I have to keep reminding myself to keep my hands clean and handle the exterior parts as carefully as possible. I did get a bit of stray glue on the BT, but successfully cleaned it off with a damp paper towel later on.

Next I lightly cleaned up the two fins and prepared to glue them. Here they are with a ruler to show how long and skinny they are.
ImageUploadedByRocketry Forum1452388196.074613.jpg

I thought there was no way I was going to get the fins on straight, supported by that small root edge, without a jig of some sort, and so out came a 1/16" version of my 3d-printed fin jig. Although I had to improvise a bit of a rig to use it (was not anticipating a 2" body tube when I designed it), everything seemed to work perfectly. Here it is holding the first fin while it dries.
ImageUploadedByRocketry Forum1452388216.336891.jpg

Two fins and 4 fillets later, the lower tube is fully assembled.
ImageUploadedByRocketry Forum1452388229.027484.jpg

That's all I have so far.
 
Three centering rings and a hook are affixed to the motor mount tube without incident. One mildly odd thing is that the instructions direct you to make three marks on the tube for them, but the first two rings are simply butted together and aligned with the top of the tube, so two of those marks were not necessary. No biggie.

Then it is necessary to peel some layers off the two top rings to enable a coupler to fit over it. This was not as quick and easy as I expected, as the layers of the centering rings did not always come off in clean pieces. Also I needed to be a bit careful to keep the two rings as much the same as possible.
View attachment 279466

Eventually, success, and the coupler was glued on. I used Elmers Glue-all for this in hopes of not having the coupler seize while being applied.
View attachment 279467

That is ODD, all right...
 
The main fin assembly (what I call it, at least) attaches to the main BT and is the monocopter blade for the spin recovery. It consists of 5 parts, and I found the construction sequence to be interesting.

First is the fin spar assembly. This presumably is for strength reinforcement of the very large and very thin fin. First, a three-piece sandwich is glued together (the large fin piece will eventually be glued in between the two spars):
ImageUploadedByRocketry Forum1452565470.656722.jpg

Next, the three-stacked root edge is sanded over the body tube to create a matching curve for better attachment. I think I did OK here:
ImageUploadedByRocketry Forum1452565484.473497.jpg

Next, the spar assembly is glued to the BT. I didn't have any jig that could hold onto something like this, so I used my eyeballs, and think I got it pretty straight.
ImageUploadedByRocketry Forum1452565499.169407.jpg

I was surprised that the spar assembly was glued to the BT before gluing in the large fin piece. Before thinking about it, I figured it'd make the most sense to build the entire fin assembly and then glue the whole thing on. After pondering a bit, I concluded that gluing the entire assembly to the BT would be difficult because its very long and swept back, with a small root edge, and would probably want to fall down without some hard-to-rig support structure. The spars are light enough that they can be glued routinely, and once they're securely attached and filleted *then* you can safely add the huge lever arm.

So you glue the large fin piece in between the spars, and then clamp the sandwich to dry. Having learned my lesson in a previous build, I put some wax paper around the sandwich, then a piece of scrap balsa on each side, and *then* applied my clamps. This prevents the clamps from leaving marks in the balsa, which they most assuredly would without the extra protection
ImageUploadedByRocketry Forum1452565510.651237.jpg

Once this was done I had to put it together to see what it looked like.
ImageUploadedByRocketry Forum1452565537.241976.jpg

I was happy to see that it could stand up properly, a little cockeyed but standing nonetheless. I'll probably store it on a dowel anyway to protect the 1/16" balsa fin corners. If it didn't affect the spin recovery, I might prefer the fins to be shaped so that the trailing edges would sit flat when the rocket was standing up, but that's just me.

Finally, a fine dowel is glued to the underside of the fin, and the entire assembly is finished. The instructions suggest this dowel is for weight, although it probably also adds a bit of rigidity.
ImageUploadedByRocketry Forum1452565564.812466.jpg

All that remains now is the nose cone, launch lug, and "finishing", whatever that means in this case.
 
Hi Neil,
Thanks for taking the time to post the build. I didn't see it until the morning of January 12.
I wouldn't trim the fins to make the model stand flat on the fin tips.
The designer, Johnathan Mills, went through many prototypes and weight issues to get it right.
Balance and light weight is critical.

The long strange shape is based on the maple seed shape.
The long fins on the bottom half also helicopter in but much faster than the single blade upper section.
The strange design is more than made up for by the helicopter performance.

Fly it first on a 1/2A engine. If you can, fly it over grass.
It seems fragile but I've never broken one in boost or landing.
The first time I launched one, I was slack jawed! The upper section almost hovers in place.
No moving parts either! Listen for the whistle on the way up.
 
I wouldn't trim the fins to make the model stand flat on the fin tips.
The designer, Johnathan Mills, went through many prototypes and weight issues to get it right.
Balance and light weight is critical.

I'm not messing with it, just idly pondering. It's probably moot anyway, because the only time I'll ever have this rocket standing on its fins is probably when posing for a picture.

Fly it first on a 1/2A engine. If you can, fly it over grass.
It seems fragile but I've never broken one in boost or landing.
The first time I launched one, I was slack jawed! The upper section almost hovers in place.
No moving parts either! Listen for the whistle on the way up.

I really look forward to flying this thing. The farm is mostly soft surface, but there are some hazards including a drainage ditch (which my Solar Warrior found on its last flight). A water landing would not be good for this rocket. :eyepop:

Oh well, it should add to the excitement.
 
Looks like a larger version of the old Centuri Moonraker, though it just tumbled.
-Ken
 
Final step (for now) is to attach the nose cone. Instructions call for a layer of white glue on the bottom to protect against ejection gasses; I put 2 layers of Glue-all and then another of Titebond II and then decided I should stop before I go crazy. In any case, the exposed balsa is now well-encased in glue.

I did a light CA-ing of the nose cone just to give it a *bit* of protection, and then glued it in, and voila:
ImageUploadedByRocketry Forum1453078562.038245.jpg

For now I am not finishing it at all. I will probably do a Sharpie job on it eventually like recommended in the instructions; certainly some sort of striping at the NC and tips of the fins should look good while spinning down from the sky. Hcmbanjo warned me that unprotected Sharpie would run if it gets wet, so I'm going to wait with it until I'm ready to clear-coat it as well (which would be final). I did a quick experience on a piece of scrap balsa, coloring it with Sharpie, and then after having a while to dry, putting some Future on it. That did not go well, the Future seemed to start dissolving the Sharpie immediately, so I will definitely not be using Future on this rocket.

So for now it remains naked, and I must wait 2 or 3 frustrating months before I can get to a launch to see this thing fly. Urgh.

All in all this was a fun little build, perfect for winter.
 
Your build looks great, and I enjoyed watching another BAR's experience with this kit (same goes for your Solar Warrior build). Thanks for making the time to post this.

I built the Cyclone a few months ago. My build was very conscientious: precisely following instructions (which are WAY, WAY better than average); Elmer's wood glue throughout; etc. My kids and I launched it twice at a local park on one of the two recommended motors, a 1/2A3-2T. Each time, the boost was perfectly straight and the two parts of the rocket descended just as promised. You will love how it looks on the way down.

Not quite satisfied, of course, I decided to double my pleasure and reached into my range box for the other, more powerful, recommended motor: an A3-4T. I didn't know at the time that this was to be my Cyclone's last launch. Almost immediately after it left the pad, my Cyclone shredded. From what we were able to recover, the large fin separated just aft of the fin-spar joint. Also one of the smaller fins split apart, again just aft of the joint. In both instances, it wasn't the adhesive that failed.... I was more upset about it than the kids.

Because I liked the Cyclone's descent so much (and also because I think a lot of Odd'l Rockets and Chris Michielssen), I purchased another Cyclone. Again, my build was very conscientious. This time, my 5 year old snapped off a fin before its first launch. Here, too, it wasn't the adhesive....

I hope you have better luck with yours than I had with mine.

Let us know how your first launch goes.
 
Ouch! I've been treating this thing with kid-gloves so far, but once it's under boost I can only cross my fingers. From the sound of things I probably will stick with the 1/2A for this one. Not that much more thrill to be had by sending it higher (easy for me to say now, from my desk).

I watched someone's rocket-boosted glider shred on the way up last year, coming down like confetti in Times Square on New Year's Eve. I would prefer not to relive that with one of my own rockets...
 
OK, I live by Mark Hayes' motto: Never Fly Naked. After my unsuccessful experiments with Sharpie and Future, the Cyclone stayed naked until I could figure out something to do with it.

Then, I bought a little bottle of black Testor's enamel to touch up a dinged fin on my Centuri, and the thought struck me that I could do the same Sharpie paint job but with nice durable brushed-on enamel. So that is what I did. There are bleeds under the masking tape, the surface is not glossy (due to the ultra-porous untreated balsa), and lots of brush marks, but I'm quite happy with the result. And the little spot paint job should weigh very very little (I wish I had remembered to weigh it before and after). It definitely helped that I had done a half-assed CA job on the nose cone, it didn't absorb nearly as much as it would have without the CA (the fins were like sponges).

Now I can say it is *finished*, in both senses of the word.

cyclone_finished.jpg
 
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The good news: I finally launched my Cyclone today!

The bad news: this happened:
launch_pics - 1.jpg

All the glue joints held but the whole thing shredded on the way up. I'll probably never know why. Looking back, I didn't spend much (read: "any") time making sure that the rocket had a completely clear path up the rod, but much larger rockets fly of those rods without problem, so I don't see how that could have been an issue. I'm just trying to figure out *any* possible explanation for why that happened.

I'm sad mainly because I never got to see it do its thing. Might have to just build another and try again (no way to repair that that I can think of).

On the bright side, a shredding rocket sure does provide some entertainment for those watching.

If anyone has theories on why this might have happened I'm all ears.
 
Well, once the first fin snapped under thrust, I would think it was all over for the other two. This is not a design that looks like it could handle skywriting.

There's about zero base drag under thrust. Your motor mount mishap moved the CG aft a bit, and possibly the enamel did the same again. Not sure what the margin was, but based on the unique design I'm guessing not much.

My hunch: the CG shifted enough to give a wobble off the end of the rod in the breeze, the wobble snapped the weakest fin, a hard left, the other aft fin snapped, and finally the main spar.

I dunno, it sounds good enough in my head. What keeps the monocoptor from spinning with the booster attached?
 
I agree that once the first fin snapped it was all over. I wish I knew which one went first, maybe it would shed some light (or maybe not :))

The rocket is rated for an A3 in addition to the 1/2A3 that I used. So it can accommodate more weight in the motor area. So it's hard for me to imagine that the very slight shift in motor position could have had that dramatic an effect. Likewise with the paint (I did put plenty on the nose cone along with some CA, so there should have been some added nose weight there to at least somewhat compensate the paint on the fins). I dunno, I can't prove anything of course. It's more of a theory than I can come up with right now, at any rate.

What keeps the monocoptor from spinning with the booster attached?

Well, with the booster attached it's a 3-finned rocket (albeit a bit asymmtrical).
 

Well, with the booster attached it's a 3-finned rocket (albeit a bit asymmtrical).

Yup; what prevents the big fin from twisting the front tube w/respect to the back rwo-finned tube, friction? Or was there some keying I missed?
 
Dang that sucks you didn't get to see it fly just once. As far as the root cause, could it be that one fin may have gotten cracked somewhere along the way? So that as soon as it was under meager thrust it let go? I know I've inadvertently snapped a fin or two on the way to the launch site.
 
I'm not *too* broken up about it (if you'll pardon the expression) because it was fun to build and I didn't have a zillion hours sunk into the finishing work (I now see why some folks require a rocket to earn its paint). But I do still want to see it fly.

After discussing it with Chris Michielssen our best theory at this point is an overly spongy sheet of balsa. A quick density calculation on the fins (which I recovered) supports that theory. These fins are 1/16" balsa and are very long, so they probably don't have much margin for error w/regard to the balsa stiffness. Anyway, it's a theory. Chris has graciously offered to send me a replacement kit, so I shall give it another go. I'm actually looking forward to having an excuse to build it again. I'll keep this thread updated with my progress.
 
I got the new kit from Chris, and indeed the balsa seems to be stiffer and heavier than the old one. Hopefully this one will hold up better.

I'm not sure when I'll have real tim to spend on this build but I did have a few spare minutes today so I thought I'd get my nose cone prep out of the way. First I CA'ed (just to harden it up a bit) and sanded it. Then I thought it'd be a lot easier to paint it before I assembled it, so I pulled out my little bottle of Testor's black, with the intention of pretty much recreating the same paint job as the last one. Having recently had a bad experience with accidentally buying flat instead of gloss white paint (the writing on those little Testor's bottles is tiny), I double checked my bottle of black and was dumbfounded to find that it too was undesirably flat. When I painted this rocket the last time, my dim-witted brain assumed that it was coming out flat because I was painting such porous, untreated balsa surfaces. Poppycock, it was flat paint all along. Which means out of three bottles of paint, I inadvertently purchased flat paint twice. Amazing.

In a fit of pique, I decided to spite the color black and give the coveted nose cone slot to my glossy red paint. I gave it one good coat and still need to touch up one spot, but it looks good. Since this rocket is mostly going to be bare, I'm not looking for the small painted areas to be perfect.
ImageUploadedByRocketry Forum1474246594.961931.jpg

Here it is temporarily inserted into the body (gonna be a while before it gets glued), and a lesson is learned: the best masking is no masking!
ImageUploadedByRocketry Forum1474246605.774285.jpg

I dunno if I'm gonna go all-red or mix in some black or what, probably will futz around a little in OR to see what looks good.
 
Cyclone II is proceeding nicely. Now where did I put the *#!% launch lug???
ImageUploadedByRocketry Forum1476483126.054188.jpg

I must reiterate what an enjoyable little build this is. I'm glad I was forced to build it again (though I do hope this one stays together. 😉)
 
Finished, ready to try again!
ImageUploadedByRocketry Forum1477432693.431191.jpg

Painting on raw balsa sucks, if I have to do it again I'd probably paper just the tips of the fins.

To take a bit of the roughness off the paint, I gave it a good rubbing with dry paper towel.
 
I am pleased to report that Cyclone II performed flawlessly at the BARC launch yesterday. Don't have any pics yet, hopefully soon.

First launch was on an 1/2A3-2T. It didn't go very high, but high enough to get a good long spin coming down. As promised, the booster unit spins down moderately, while the mapleseed part gets up a pretty good rate of spin and comes down slowly.

Given the huge flat recovery area, I got ambitious for the second launch and stuck in an A3-4T. That got some good altitude, and a nice long spinning descent. Unfortunately I made a stupid mistake and watched the final descent of the booster piece while asking others to keep an eye on the mapleseed. They *all* lost sight of it, so after some searching I was becoming resigned to having lost it, until some time later my Dad located it somewhat further away that I imagined it could have traveled. So thankfully it's all back together safe and sound.

The takeaway: in the future I personally will focus exclusively on the mapleseed part, and not trust anyone else to follow it. The booster unit doesn't drift that far and should be easy to fine. The A3-4T was a great engine for a launch at a large club field, with easy recovery areas, but for smaller fields definitely the 1/2A3-2T is plenty.

All in all a very fun rocket, I look forward to flying it some more.
 
Great to hear Neil!
I've seen a Cyclone spin and drift out of sight on a A3-4t before.
At my local soccer field launch I had a prototype drift and land in someone's back yard on the 1/2A3-2t.
Definitely keep an eye on the upper half. The lower half tends to land much closer.

I'm happy to hear of your success, many are surprised how well it helicopters in with no real moving parts.
 
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