Recycling container Jayhawk

troj said:

In rocketry, it's not the flights that matter, it's the people. In the end, the rockets are what draw us all together. Kevin

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This is one of my favorite quotes, as it sums up the common interest and shared experiences that bond us all together. While belonging to a national organization (NAR, Tripoli) is a requirement to maintain certification, among other benefits, in all honesty, the most satisfaction I get in sport rocketry is at the chapter level. So much so that I belong to two NAR chapters… the Wisconsin Organization Of Spacemodeling Hobbyists (WOOSH, section 558) and Fox Valley Rocketeers (FVR - section 683)

Friend and fellow WOOSH member Marc S. came up with a novel starting point for a new group project. He found a supplier of giant plastic bottle recycling containers, which would be a perfect (somewhat) starting point for a short, fat rocket. The minimum order was four, and we persisted until finding enough rocketeers willing to participate in this endeavor. In early December, we took delivery of four of these heavy plastic, two-piece cans. Marc and I each claimed one, the other two went to Bill B. and Jackson L. The plan is to have them all ready to fly at the WOOSH "Eat Cheese or Fly" launch in August 2011.

It is no secret that I like Jayhawks. I have 14 of them. My 10" diameter version recently flew at Midwest Power 8 (2010) and is prepped and ready for a second chance at LDRS 30 (Sep 2011). In the interim, rocket flying opportunities wind down a bit here in the Great White North(ern) Illinois, but winter provides an opportunity to build things. Using one of the four giant recycling bottles, I have started my fifteenth Jayhawk. It should launch at under 100 pounds, so she will be equipped with a single 98mm motor mount. I haven't settled on a name yet, but "Pepsihawk" and"Jaycoke" have both been suggested. Open to ideas here.

Pretty funny!

looks like you have enough area on the bottom would you consider clustering or staging. wroth an area so large you can almost do anything.

It's wonderful.

You have to let me copy it to the Jayhawk gallery...please!

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Oops!

I see you already have.

Thanks!

Sounds like it might not be ready for "stubby rocket day" this saturday, huh? Bummed.

bandman444 said:

looks like you have enough area on the bottom would you consider clustering or staging. with an area so large you can almost do anything.

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I'm planning on a big cluster with some 17" Sonotubes I have put aside for a later project, and I am also working on a 2 stage upscale of the Estes SM-3 Seahawk. For this odd roc, though, I plan on keeping it simple with the single 98mm mount. A Polecat 7.5" tube fits perfectly up into the nose cone (bottle cap), so I am using that size tube for my inner body, to which the wings will attach, and inside of which will be the motor and recovery gear. Adding a coupler makes a simple nose cone shoulder for ejecting the top. I used the same technique (with a smaller tube) for my Hershey's Strawberry Syrup Jayhawk and my Crayhawk (Crayola Jayhawk). The "rocket within a rocket" adds some strength to what otherwise would be a difficult assembly, as not many adhesives bond well to plastics.

what does the empty can weigh?

bandman444 said:

what does the empty can weigh?

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The empty bottle is 14 pounds. The wings are usually the Jayhawks heaviest component. I'll have to add some nose weight to the top for stability, and foam to the bottom to hold its shape. Rocksim currently shows it at 69 pounds with an L3150 (98-2G) motor.

with such a large volume of foam that could get pretty heavy Another suggestion is to build a structural interior or something like large centering rings.

sorry for my two cents

bandman444 said:

with such a large volume of foam that could get pretty heavy Another suggestion is to build a structural interior or something like large centering rings. sorry for my two cents

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The whole bottom won't be foam, just the bottom of the bottle up to the first centering ring. Enough to save a big dent if it hits something. And yes, there are some big rings in it (three). The motor mount has rings inside the 7.5" tube, which in turn has rings to center it in the plastic bottle. They show as green in the Rocksim screen shots.

I've made some progress on the motor mount. Sized to fit a max of 98/10240 casing, it will fit into the 7.5" inner rocket body. As fellow bottle-teer Judy so eloquently phrased it, the rocket wears the bottle like a dress.

I am a big believer in distribution of forces. The top ring is tied to the next ring with all-threads to spread the tension (pulling) force from the opening shock of the recovery system. The bottom ring will be tied to the second ring with ribs to pass along the compression (pushing) force from the motor during boost.

Putting the finishing touches on the bottle design. Mark at Stickershock23 will be doing the wrap. Here is a sneak peek.

(Or a misdirection...)

:wink:

I just saw this thread. I was going to use a play on the old Pepsi ad slogan and suggest "Jayhawk Generation"

Peartree said:

I was going to use a play on the old Pepsi ad slogan and suggest "Jayhawk Generation"

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Thanks. "The Choice of a New Generation." I really liked that ad campaign, back in the 1980's I believe, when Michael J. Fox and Martin Sheen were spokesmen. I have sent sponsorship inquiries out to both Coke and Pepsi - we'll see if they respond. (I know it's a long shot... Kraft Foods turned me down in 2007 on a similar request for a WOOSH cheese lofting contest we have annually at Eat Cheese or Fly.) If you get sponsored, though, you have to give up your amateur status. At least by NCAA rules.

Peartree said:

I was going to use a play on the old Pepsi ad slogan and suggest "Jayhawk Generation"

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Well, the Pepsi motif is definitely out of the question...

"Dear Sather,

Thank you for contacting us at Pepsi-Cola regarding a possible sponsorship opportunity. We sincerely appreciate your offer to help advertise our products!

I am sincerely sorry that we are not able to assist you with your request. As you might imagine, we receive thousands of sponsorship requests for local, national, and even international affiliations. While we would absolutely agree that our loyal consumers are the best spokespersons and advertisers for our beverages, our funding for such partnerships is limited and usually determined well in advance. For that reason, I regret that we’re not able to offer assistance for your sponsorship request at this time.

Thanks so much for thinking of us. We wish you the best of luck in all that you do!

Sincerely,

Margaret Corsi
Consumer Relations Representative

DID YOU KNOW ... *** All of Pepsi-Cola’s plastic soft-drink bottles contain an average of 10% recycled plastic, and the average aluminum can contains 40% to 50% recycled aluminum. ***"

Well, at least they were nicer than black rocket.

looking good on paper when does the build start?

stickershock23 said:

looking good on paper when does the build start?

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As we speak... I finished the motor mount today. All-threads spread the tension (pulling) force of the recovery system from the top ring to the next ring. Ribs spread the compression (pushing) force of the motor during boost from the bottom ring to the next ring. Wing tangs would normally serve this function, but this motor mount fits inside another tube, the 7.5" stuffer tube to which the wing tangs will attach.

Looking good! How long is your motor tube? Or, what I'm really asking is - what is the largest case size that you'll get in there?

JLRockets said:

Looking good! How long is your motor tube? Or, what I'm really asking is - what is the largest case size that you'll get in there?

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28" long, to fit a max of 98/10240 casing (although I doubt I would ever use that much AP on this)

Well, I am at one of those points where I have to make a decision before continuing, or else run the risk of having to trash some parts and backtrack. I had originally planned to have the top section come off where it is already segmented, deploying the laundry from what is basically the mid-point of the airframe. As I trial fit the pieces together and give it further thought, it makes a little more sense to "pop" the cap off the bottle and deploy at least a drogue out the top to stabilize it before letting out the mains. In my head I still relive the tangled mess of shock cords that resulted from tossing out 5 parachutes at apogee with my upscale Death Star. If I could be assured the bottle was stopped in midair, it would be easy, but FMEA predicts some forward velocity and the possibility of tumbling, so I need to sequence things to control deployment(s). Hmmmmmm.

SMR said:

Well, I am at one of those points where I have to make a decision before continuing, or else run the risk of having to trash some parts and backtrack.

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Well, after two months of pondering, I finally committed to chopping off the top. Adding a 7.5" tube and coupler to the bottle cap will convert it to a nose cone, which will blow at apogee. A compartment directly under cap will house the drogue, which will inflate and then pull off the upper bottle half, exposing the main(s). This should help sequence the recovery system deployment, while reducing the pressurized volume and BP required to initiate the apogee event. I marked the tube with masking tape, and cut it with a fine tooth backsaw. This left thousands of little, static clingy pieces of black plastic on everything. Better get out the vacuum...

This week I finished mounting the motor mount (98mm motor tube and 7.5" centering rings) into the 7.5" Polecat core (stuffer) tube, which goes up the entire length of the rocket (in sections) into the "nose cone" bottle cap. Here she is, with a trial fit of the Aero Pack retainer, which will be mounted to the aft ring through the skin of the bottle, once it is permanently installed. The second photo is the bottle cap, upside down, with a length of coupler to function as the nose cone shoulder.

Next on the agenda is cutting the giant centering rings to mount the core tube into the body.

Sather, you have so many HPR projects going @ approximately the same size--if I did that I know I'd end up gluing the wrong parts together some how, some where :eyepop:

dixontj93060 said:

Sather, you have so many HPR projects going @ approximately the same size--if I did that I know I'd end up gluing the wrong parts together some how, some where :eyepop:

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That's still a possibility... they're not finished yet. If I was better at planning ahead, I'd have 'em color coded or something.

Looks like it is going to be a fun rocket to fly when you are done.

That is a fantastic idea. I might have to look for one of those recycling containers.

Okay, we're back from spring break vacation and time to get back to work. I've been putting this next step off for some time, now, but several subsequent steps rely on it, so I need to get 'er done. Today I laid out the rather large centering rings for the Jaycoke. They use 11 ply, 3/4" thick birch plywood, are approximately 18" in diameter, and will have 7.5" holes for the core tube, as well as lightening holes for weight reduction. The top ring also holds the avionics bay, and will be skinned with cabinet plywood to eliminate one of many failure modes, (the one where the recovery system falls through the lightening holes during boost.)

It was a beautiful day, today, so I dragged some stuff I have needed to cut and sand out of mothballs and got to work. I started with the G-10 bands for the avionics bays of Isaac Newton and Pegasus, and then pulled out the big centering rings for the Jaycoke. That pretty much took the rest of the day. I cut the perimeter outlines with a jigsaw, and then fine-tuned the edges with a turn-table jig on my disk sander, until they fit snugly inside the bottom of the recycling container bottle. (This would have been a LOT easier with a router, but I lack the proper attachment to do rings of this size.) The center hole was done in much the same manner, using a drum sander to size the center hole for the 7.5" core tube. When satisfied that everything fit properly, I trial fitted the rings to the core tube, and then the core assembly into the recycling container itself. Next up are the wings. Starting to build a little needed momentum as we get closer to Eat Cheese or Fly, on 27-28 Aug 2011.

T minus 140 days...

Today I cut patterns for the main wings (red) and winglets (green). Note the size comparison between the Jaycoke winglet and the winglet from the 10" diameter Jayhawk (orange). Since the rocket is quite a bit "stubbier" than a scale Jayhawk, the wings and winglets are compressed vertically as well.