Calling Pem Tech, and all others who have built the King Kraken

[BsSmith]

I think I messed up!

When I cut out my fins for the Kraken, they seemed right, there was only a tiny bit of extra tubing left and they were all the same size. Then I looked at the pictures of everybody elses Krakens and my fins seem smaller then all the others! Or, it could be some odd illusion from the metallic paint. Now I need to find out if I need more nose weight. The CG of the rocket is at about 16" from the base, and the fins are about 13" long. I'm still going to add glue and an Aeropack to the back of the rocket so the CG will still move back a little. The first picture is just the rocket, the second is my CG mark (the little piece of masking tape), the third is the picture on the destructions, the fourth is a picture that Layne posted on another thread of his stable one, and the fifth is mine at a similar angle.

 

[Luv2launch]

13 inches is about right for those tube fins, as for nose weight you got the bag of lead with your correct?That should be all you need.One suggestion I have though you might want to sand out you launch lugs a bit the Loc lugs tend to expand and contract with varying temps so I find its a good idea to run some sand paper through them a bit.

PS Heres a pic of mine before the nastie zipper that the big bad G76 put into it a couple weeks back.

 

[Pem Tech]

Brian,
Fear not, you have completed your King Kraken correctly, all production King Krakens have 13.5 inch fins/tubes. The glamor shot and take off picture are of the original KK which did have longer tubes/fins, but the length was shortened to increase the margin of stability so short tubes/fins it was.
Your CG is pretty close to what we have found it to be but, considering the Aeropack, a little more ballast would be a good idea. Say, another .25 to .75ounce would give you a sufficient margin of stability.

The calculated CP is ~8 inches from the aft, so to be sure, stuff your KK with your intended motor, measure the CG and find your margin.
Let me know if we can be of any futher assistance.

Nice work you did there....
She is a beauty.

I think I messed up!

When I cut out my fins for the Kraken, they seemed right, there was only a tiny bit of extra tubing left and they were all the same size. Then I looked at the pictures of everybody elses Krakens and my fins seem smaller then all the others! Or, it could be some odd illusion from the metallic paint. Now I need to find out if I need more nose weight. The CG of the rocket is at about 16" from the base, and the fins are about 13" long. I'm still going to add glue and an Aeropack to the back of the rocket so the CG will still move back a little. The first picture is just the rocket, the second is my CG mark (the little piece of masking tape), the third is the picture on the destructions, the fourth is a picture that Layne posted on another thread of his stable one, and the fifth is mine at a similar angle.

 

[Pem Tech]

Hey!
Beautiful rocket you got there....
Did you get the zipper fixed?

13 inches is about right for those tube fins, as for nose weight you got the bag of lead with your correct?That should be all you need.One suggestion I have though you might want to sand out you launch lugs a bit the Loc lugs tend to expand and contract with varying temps so I find its a good idea to run some sand paper through them a bit.

PS Heres a pic of mine before the nastie zipper that the big bad G76 put into it a couple weeks back.

 

[JAL3]

If a navy blue pickup driven by some long haired teenagers shows up in the recovery area...shoot first.

Then see if they have mine in the back of their truck.

 

[Luv2launch]

Hey!
Beautiful rocket you got there....
Did you get the zipper fixed?

I just got the coupler in the mail a couple days ago with a couple bulk heads I am thinking of making a baffle when I rebuild it.I just need to make a jig to cut the body tube straight and figure out how much I am going to cut off.And scrounge up a bit more lead to drop into the nosecone to make up for the extra weight towards the rear end.

 

[Pem Tech]

If a navy blue pickup driven by some long haired teenagers shows up in the recovery area...shoot first.

Then see if they have mine in the back of their truck.

FOr stealin' your KK, shootin' is too good for em'!

 

[JAL3]

FOr stealin' your KK, shootin' is too good for em'!

You're right. The cure is a tall tree and a short rope.

 

[MartyAMC]

I thought the same thing when I designed and cut the tube fins for my monster. But after checking and rechecking my calculations I was convinced and proceeded with construction. Still need to finish the nose cone and add the canards, but it's coming along.

 

[roadkill]

I thought the same thing when I designed and cut the tube fins for my monster. But after checking and rechecking my calculations I was convinced and proceeded with construction. Still need to finish the nose cone and add the canards, but it's coming along.

WHOA !!

Would that be the King Kong Kraken....
:jaw:

 

[MartyAMC]

I'm just callin' it "Kraken-Up".

 

[BsSmith]

Glad to see that I didn't mess up the rocket! Now, if only my red paint didn't look pink...

Marty, that is a great looking rocket! The flight should be spectacular!

 

[MarkII]

You're right. The cure is a tall tree and a short rope.

Which is why I figured that it would be better to hire that job out...

Hey, you didn't do a half bad job on it!

MarkII

 

[Pem Tech]

I thought the same thing when I designed and cut the tube fins for my monster. But after checking and rechecking my calculations I was convinced and proceeded with construction. Still need to finish the nose cone and add the canards, but it's coming along.

Marty, you still interested in a scale pattern for finishing? If so I will pin Trudy down and make her draw one out for you.
Some jiggly eyeballs would be cool too...

 

[Bill P]

I'm just callin' it "Kraken-Up".

Love the name.

 

[MartyAMC]

Marty, you still interested in a scale pattern for finishing? If so I will pin Trudy down and make her draw one out for you.
Some jiggly eyeballs would be cool too...

Layne,

No decision yet. I do plan to put eyes on the canards but still undecided about the body. I can do pretty good with rattle cans but I'd like to step it up a notch with this one. I've got my daughter asking around her college art department to see if anyone's interested in painting a squid design.

I'll keep you posted.

 

[MartyAMC]

Love the name.

Thanks Bill

It was the best I could come with before I submited my TAP package. Although I like roadkill's suggestion too.