Build Thread: Pemberton Technologies King Kraken for Level 1 Cert

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IMG_0367.JPG I have tried both ways and don't think there's much difference. I guess the deciding factor is if you like more room between the rail buttons than the fins are long. After this is when I started to think about glassing the outside of the tubes. I used several large headed pop rivets thinking it would secure the fins and they were absolutely no help.
 
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AHansom said:
I have tried both ways and don't think there's much difference. I guess the deciding factor is if you like more room between the rail buttons than the fins are long. After this is when I started to think about glassing the outside of the tubes. I used several large headed pop rivets thinking it would secure the fins and they were absolutely no help
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Wow, that's a spectacular shredding. Even blue tube. What motor did it take to do that damage?
 
It was quite a crash. Kind of showing off for my sons Boy Scout troop I put a bigger motor in than usual A CTI M-2020 was a little to much for the 6"x 96" Kraken.
 
Are you still on track for Red Glare? Have you picked your favorite flavor of motor? Are you thinking of limping in with a small H or gritting your teeth and holding your breath with a big I? Interesting going DD, lots of fun stuff to work out. looking forward to seeing the pictures and video!!!!
 
AHansom said:
Are you still on track for Red Glare? Have you picked your favorite flavor of motor? Are you thinking of limping in with a small H or gritting your teeth and holding your breath with a big I? Interesting going DD, lots of fun stuff to work out. looking forward to seeing the pictures and video!!!
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I think so, 6 weeks, 2 days, and 20 hours. Clock is ticking, as long as I can keep finding time here or there, I'll make it. Right now I just need decent weather to paint outdoors.

I'm planning on an Cessaroni H143, Smoky Sam. That dark smoke looks inky. I probably won't get DD setup and working by April, but I want to build it to be ready for DD.
 
Alright, snuck away for a few minutes to make some progress, but the smell of primer throughout the house gave my location away! Rail buttons will go on the side opposite the 1/4" lugs. Hope to finish priming and sanding this weekend.

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First coat is done, will add a second coat if there is time and weather allows.

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Blargh! Somewhere under that black are my carefully marked rail button positions....

Tonight the motor tube has been glued in, priming the fins has been completed, and avionics bay is started. A package arrived from Eggtimer, so time to move over to the other bench.
 
Still no good painting weather! I can at least put the avionics bay together. The eggtimer is soldered, and the bay is coming together.

How do you deal with the switch band awkwardness? I see two approaches, either mount the switches into the band, and have connectors going to the electronics, or mount the switches to the sled, and have access holes through the switch band to access the switches. What is your favorite solution?

I made screw switches from two sided PCB and surgically implanted them into the switch band.

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Hoorah, a beautiful day! Time to get some painting done. I masked off the inside of the fin tubes, and used a trick I read about here in these forums. I painted the bottom paint color over the tape seam, and let that dry to the touch. If that paint bleeds under the masking tape edge, it doesn't matter, because it is the same color. Then black on the outside.

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Now all you need is a steady hand and good brush to paint the edge between yellow and black a bright RED! Just a really cool detail.

Orange might work too!

Great build...
 
Thanks!

Oh man, I can visualize the red pin striping on that leading edge. That would look sharp! I wonder if I could pull it off......
 
Best of luck and skill to your cert flight. Usually the up is easy; down is harder. Things you can do to improve recovery odds are ribbon fold the shock cord in a Z pattern in your hands, so it unravels nicely and have a flyer at the field show you how to pack a chute properly if you’re struggling with packing neatly.

Most RSO’s won’t nick pick your recovery gear when you bring it to the table. So a friendly mentor is always a nice ally to check your doing it right. Don’t forget to mark the CP location. Usually people at flying fields will bend over backwards to help a new flyer get a cert done.
 
Andrew_ASC said:
Best of luck and skill to your cert flight. Usually the up is easy; down is harder. Things you can do to improve recovery odds are ribbon fold the shock cord in a Z pattern in your hands, so it unravels nicely and have a flyer at the field show you how to pack a chute properly if you’re struggling with packing neatly.

Most RSO’s won’t nick pick your recovery gear when you bring it to the table. So a friendly mentor is always a nice ally to check your doing it right. Don’t forget to mark the CP location. Usually people at flying fields will bend over backwards to help a new flyer get a cert done.
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Thanks Andrew, I appreciate the input. I also ordered a slightly larger parachute from spherachutes to get a descent rate closer to 15 ft/sec. Adding the avionics bay and doing the fiberglass added some weight, so it is heavier than the original kit design. I'll stick to motor deploy for the cert flight, and send the altimeter along for the ride.

That's a good idea about marking the CP. I have two different Rocksim files, one from the Apogee website, and one from Layne himself of Pemberton Tech. I'll have to compare the CP positions and see if they agree. The tube fins slightly complicate the simulation.
 
Fantastic looking and great photo effect. Going back through your thread a bit looking at the pictures, I didn't see if you have vent holes in the body tube? Good Luck, its almost time to release the Kraken!!
 
AHansom said:
Fantastic looking and great photo effect. Going back through your thread a bit looking at the pictures, I didn't see if you have vent holes in the body tube? Good Luck, its almost time to release the Kraken!!
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Thanks, I had fun playing around with bike lights.

I don't have vent holes yet, I'll need to add some for the altimeter in the payload bay. I need to re-read the manual for the Eggtimer again and figure out how many holes it needs, and what size. I've done dual deploy once before in a mid power rocket, but didn't pay too much attention to some of those details. I figure I ought to do this one "right". Any recommendations?
 
AHansom said:
I didn't see if you have vent holes in the body tube?
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Thanks for that comment! I was thinking of altimeter vent holes in the switch band, but your comment sent me looking, and I realized I need to vent the upper and lower airframe. I drilled some vent holes tonight, probably wouldn't have known about that otherwise.
 
AHansom said:
Waiting for photos of the newest level one Kraken!!
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Yes, it was successful, but not without a minor complication! The boost was nice, with a slight kink, and deployment was basically right over our heads. The 8 second motor delay was just about right. The parachute from spherachutes (beautiful parachute!) deployed cleanly and it floated gently over the parking lot. There were only a few trees behind the parking lot, and the Kraken managed to find them. Fortunately, my friend and I managed to get it freed, and it came down on the gravel. If the pole had been a few inches shorter, or the rocket a few inches higher, the pole wouldn't have reached. That was one of the luckiest unlucky rocket recoveries I've had.

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The Kraken was in fine shape, a few scratches on the nose cone from the gravel, but otherwise not much else.

The rest of the day at Red Glare was firing off more rockets and watching many impressive launches.
 
Andrew_ASC said:
Best of luck and skill to your cert flight. Usually the up is easy; down is harder. Things you can do to improve recovery odds are ribbon fold the shock cord in a Z pattern in your hands, so it unravels nicely and have a flyer at the field show you how to pack a chute properly if you’re struggling with packing neatly.
Click to expand...

Thanks, I did the Z-fold with masking tape, and the deployment went very smoothly.
 

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