Upscale Death Star

[SMR]

I have been making forward progress on the wing fillets. I am doing this in conjunction with the Jayhawk fillets, as the steps are the same and I am able to use leftover epoxy from that project (with really long fillets) for the relatively short seams of this rocket, which makes it a bit more efficient time-wise, and minimizes waste.

This is basically a 12 step process, three procedures repeated four times, rotating the rocket assembly 90° between each step. Each step takes a day to cure. (a) Lay down a small exterior fillet of JB Weld. This prevents epoxy from the interior fillets leaking out onto the fins. You can do adjacent sides of two fins at a time. (b) The aft centering ring has not yet been installed. Apply fiberglass tape along interior fin-body seam to spread bonding area up side of body and along fin tang. Add a generous fillet of West Systems 105 epoxy and 206 slow hardener. Imbed hardwood dowel into the bead. (c) Apply exterior fillet of West Systems epoxy and micro balloon filler. Add fiberglass tape along exterior fin-body seam to spread bonding area up side of body and along fin.

 

[SMR]

I started the first interior fillet today. 1st photo is of the interior seam between the body tube and fin tang. 2nd photo is after epoxy, fiberglass tape, and dowel installed. (Sorry for the quality, but attempting to control the depth of field during flash photography makes it a tough picture to take.) Blue tape is to protect the area of the aft centering ring from epoxy drips.

 

[DANLK66]

Looks great Sather!

I have been in catch up mode these past couple days and have done the following:

Cut all the body tubes and motor mount tubes to size.
Cut the slots for the fins.
Finished glassing the ball.
Cut out the hole in the base of the ball for eth body tube.
Assembled all the couplers with their hardware.

I can now start to epoxy everything together and add the laser dish to the ball. I can never resist putting all the parts together and taking a picks of what it will be. It helps to keep me motivated.

Dan

 

[stickershock23]

WOW, that thing is HUGE.. I love it

 

[DANLK66]

Thanks I like the picture of the inside. It is always scary inside the Death Star:dark:

 

[SMR]

This evening I also cut the 8" Styrofoam ball in half.

I stuck 2 pushpins into the approximate "poles" of the ball, then spun it by hand, adjusted the position of one pushpin, spun it again, adjusted again, and spun again, until the ball was spinning around its axis on the pushpins.

Then I wedged a pen under some books and edged the ball up close to the pen while spinning it. That drew a pretty decent approximation of the "equator" on the ball.

One of the great things about the forum are that many techniques people document are directly applicable to other projects. Thanks to JRThro for this one, from his BT-60 Upscale Death Star build thread, here...

https://www.rocketryforum.com/showthread.php?t=12611

Thank you, John! :clap: The large exercise balls that Dan and I have been using have parallel "lines of latitude" on them, but when they are inflated, the two poles aren't directly opposing. So, the existing lines are not actually parallel and therefore unusable. My ball is a little heavier than John's, so holding it while spinning was not an option. So, I centered the ball on my teenager's stereo turntable (thanks, Will), using a short length of LOC body tubing. This allowed me, at 45 RPM, to find the north pole, and then mark the equator. I will next sub-divide the equator into 4 equal lengths, and with string, mark the four "lines of longitude" from the north pole to south pole that will be used to cut the ball into four sections. Once the ball is cut, plywood bulkheads are next on the agenda.

 

[JRThro]

One of the great things about the forum are that many techniques people document are directly applicable to other projects. Thanks to JRThro for this one, from his BT-60 Upscale Death Star build thread, here...

https://www.rocketryforum.com/showthread.php?t=12611

Thank you, John! :clap: The large exercise balls that Dan and I have been using have parallel "lines of latitude" on them, but when they are inflated, the two poles aren't directly opposing. So, the existing lines are not actually parallel and therefore unusable. My ball is a little heavier than John's, so holding it while spinning was not an option. So, I centered the ball on my teenager's stereo turntable (thanks, Will), using a short length of LOC body tubing. This allowed me, at 45 RPM, to find the north pole, and then mark the equator. I will next sub-divide the equator into 4 equal lengths, and with string, mark the four "lines of longitude" from the north pole to south pole that will be used to cut the ball into four sections. Once the ball is cut, plywood bulkheads are next on the agenda.

What a great idea! I'm sure you got a more accurate "equator" marking than I did. I've been working on cutting the fins, cutting the TTW fin slots, and gluing on and filleting the fins, so my ball (as it were) is still just cut in half. But I'm going to have to get back to it soon, since I'll run out of other things to do.

 

[DANLK66]

I forgot about this picture of laying out the fin slots. It worked out well. Just make sure everything is level and make dots along the laser beam.

 

[DANLK66]

I did not have access to a turn table as I could not convince my wife that it was needed to tune the Death Star. I picked up a Lazy Susan swivel and made my own. I put a flashlight in a piece of body tube and drilled a hole in the bulk head at the top of the body tube that will be in the ball. After spinning the ball around until I felt is was centered I was able to see the light in it through the fiberglass and marked it with a marker. I will bolt the body tube to the ball and then will foam the entire ball as my Death Star will not be breaking into 4 pieces at deployment.


Dan

 

[El Phantasmo]

Are you sure it isn't a small moon?

 

[luke strawwalker]

Are you sure it isn't a small moon?

"That's no moon... It's a SPACE STATION!!!!"

Sorry couldn't pass that one up... LOL

Later! OL JR

 

[SMR]

Today I finished the last of the interior fillets in the motor section of the body tube. This wasn't especially difficult, but took a little extra time, as I accomplished this by using excess epoxy from the 8 interior fillets of my 10" Jayhawk project, so as to minimize waste. The time delay became a factor as I didn't always have leftovers on the Jayhawk, so some Death Star fillet building was delayed until the next opportunity.

In any event, there are now fiberglass tape and dowel-reinforced interior fillets on each side of every fin, at both the fin-motor tube joint and the fin-body tube joint. The length of the fin exterior to the body is significantly longer than the length of the tang, which gives a lot of leverage to break something on ground contact in the recovery, so my next steps are to foam the interior body cavity, and apply fiberglass tape to the exterior fillets. At that point, by early next week, she will be ready for fill and paint.

Six weeks to go!

 

[SMR]

The last few days have been spent catching up on the Death Star booster section. In the first photo, 2-part expanding foam has been added to the space between fin tangs. The excess has been trimmed in the second photo. I had to bore down a little deeper in one of the four cavities, to fit the hardwood block on the forward side of the aft centering ring, the attachment point for the rear rail button. In the third photo, the aft ring has been installed. Beads of JB Weld were added to the inside of the body tube and outside of the motor tube, which formed the fillets on the forward side of the aft centering ring as it was pressed into position. It was then left aft-end down to cure. The final steps were trimming the motor tube to length, adding the fillet on the aft side of the aft centering ring, and installing the 54mm Aero Pack motor retention body.

 

[SMR]

The original fin fillets were done to seal any exterior gaps prior to glassing interior fillets, to keep the epoxy from leaking onto the exterior surfaces while curing. A second, thicker layer is now being applied, over which a glass layer will be added.

 

[luke strawwalker]

Vader: "The Death Star WILL be completed on schedule!"

Emperor: "You have done well, Lord Vader... and now I sense that you wish to continue your search for young Skywalker...."

Vader: "Yes, my master..."

Emperor: "Patience! In time, he will seek YOU out, and when he does, you must bring him before me. He has grown STRONG... only TOGETHER can we turn him to the Dark Side of the Force! (Pause) Everthing is proceeding as I have foreseen... (laughing maniacally)"

:dark::dark::dark:

Later! OL JR

 

[SMR]

some things are just plain wrong

 

[McKailas Dad]

Pleeese tell me thats is not what Scott is wearing to ECOF! :y:

Maybe he could fly this while he's at it...

 

[SMR]

I sometimes put multiple launch guidance on my bigger rockets, to give some flexibility on launch day. This one has 1500 series buttons on one side, and 1/2" lugs on another. The glass layer over the fin fillets will help hold them on. I haven't decided yet how the rail/rod will go up through the ball, but I also plan on using the booster with different "nose cones". Like a giant glowing pumpkin for Halloween night launches, a payload shroud for the Legged Lander challenge, etc. Indecision is the key to flexibility.

 

[SMR]

some things are just plain wrong

And it gets worse....

 

[DANLK66]

I am in a whirlwind of building but things are going well. I cut out the circle for the laser disc and glued it in. I also sanded everything on the inside so that tomorrow I can come back and put a good fillet on the inside. I will then come back and sand everything down on the outside. I will have the last fin on tomorrow and then keep adding all the fillets on the fins. I have to add foam to the ball yet and decide if I want to add a channel for the launch rail or stop it at the base of the ball. I have enough power with the Vmax to not need it but it may be nice to have in the future for other motors. Still having fun but entering the Panic, build, Panic, build stage. :bangpan:

 

[SMR]

Still having fun but entering the Panic, build, Panic, build stage.

The laser eye looks great, Dan. I wish I could be as calm as you. I spend a LOT more time panicking. Which would make a good Darth Vader breathing sound emulator.

 

[DANLK66]

Remember this is my first "BIG" project and I am still learning from you how to do it. I am sure I will learn how to panic more as we get closer to ECOF :cyclops:

 

[SMR]

The Eat Cheese or Fly Regional Launch (https://www.wooshrocketry.org/) is getting close now, so I better get going and finish this thing. I have measured and marked the Death Star ball to quarter it, and bought a fresh pack of Dremel high speed cutting wheels. Be back in a few hours.

 

[SMR]

Well, my few hours has come and gone. Halfway done with cutting. Should be done before the "Dark Side" gets here.

 

[SMR]

The "Dark Side" was successfully held at bay, but the mosquitos were sure out in full force in the early evening. Prior to cutting up the ball, I had preserved the option of, if time limited, flying her with the ball intact. No longer an option, so I must now get all the bulkheads cut and assembled. 3 weeks to go!

 

[DANLK66]

Looking great Sather!

I have all the fins on now and found out it is officially a pain in the butt to move around now. Lucky for me with the move at work they cleaned out a small room that I can store it in for now. Panic, build, Panic build!

Dan

 

[SMR]

I have all the fins on now and found out it is officially a pain in the butt to move around now.

I still haven't figured out how to fit mine in the car yet. Bet you're glad you have a pickup.

Your laser eye is looking great!

 

[SMR]

Today we designed a template to mark the Death Star bulkheads. Gonna be busy tomorrow, basically have to cut out eight 25" centering rings.

 

[DANLK66]

I have a twisted notion in my head that I can get the bottom section inside my quad cab but reality should set in soon. I may have to barrow a van to avoid getting pulled over with such a weapon of destruction as a Death Star rocket. Getting it there is far down on the list but will need to be addressed as I can't afford to fly it there with 400ft flights.


The template looks great. Keep up the good work! You are getting close to the finish line.


Dan

 

[CharlaineC]

so each half will come down on its own chute. what happens if it shangs?