L1 certification build - King Krãken

[JimiB]

Though I'm still pretty green, I've decided to start my L1 Certification build.

It's only my 3rd rocket build since re-finding rocketry earlier this year so I hope I'm not getting ahead of myself. I plan to take it slow and not attempt anything really outlandish. Should be able to do a few more launches with my previous 2 rockets on larger engines before this one is ready. Hopefully will learn something useful from those along the way.

That said, instead of picking a really simple rocket, I chose the King Krãken. If you ignore the tube fins it seems to be a very simple build. Ah, but those tube fins. Plenty there for me to screw things up along the way. We'll see. My previous build was a Pemberton Technologies Screamin' Green Meenie which also has tube fins of a different sort. Guess I'm attracted to the look.

Photo is attached (hopefully) of all the parts unboxed. Along with the basic kit, I picked up a 29-38mm adapter, a 38mm retainer, and some Fix-It Epoxy Clay - all purchased from Apogee.

I'll try to post and document along the way. Sarcasm, mockery, and derisive commentary is expected and mostly welcome. I know you all mean well. :wink:

 

[Bat-mite]

Have fun with the build. FWIW, epoxy clay is heavy and brittle. I wouldn't put it on my rocket. YMMV

 

[JimiB]

FWIW, epoxy clay is heavy and brittle. I wouldn't put it on my rocket. YMMV

Thanks for the tip. It was recommended on the Apogee site for this kit so I picked some up just to see what it was. Feeling spendy I guess. Thought I would research it here before applying it.

 

[Bat-mite]

It is awful for fillets -- too brittle and will crack and separate from the BT. At least one of Apogee's videos shows it being used to fill spirals. I tried this once, and it was okay, but a lot of work. Do some searching for better ways to fill spirals.

 

[A-N-D-R-E-W]

Welcome and good luck on your build! Plenty of good information on this site if you ever have questions or want to see what other people have done! Take plenty of pictures along the way.

 

[AHansom]

Follow the destructions and you wont have any problem with it making a great flight. Its a super cool rocket just not a speed demon design, so don't overpower it!!!

 

[qquake2k]

Here is rbelknap's build thread of a King Kraken used for a Level 1 cert. I was there for his successful cert flight.

https://www.rocketryforum.com/showthread.php?38181-King-Kraken-(L1-Certification)-Build-Thread

 

[G2Rockets]

Good Luck with the build and flight. Level 1 seems scary when you are attempting it, but looking back it won't seem so bad. Have you planned what motor you will be using? I agree with the others. The clay isn't the most efficient way to go. I use 2 part jbkwik or weld on my L2 and under builds with no problems. You can also use West systems G5 which is also a two equal parts epoxy. G5 is a little runnier but if you like it, you can add filler to thicken it up.
Tube fin rockets are nice because they have a lot of drag and altitude is rarely an issue. Just be aware that if you sim it, there can be some dependencies in the altitude due to drag, which in return effect your delay time. I flew a 6" upscale of the estes super neon on an M1230 and only reached 4400 ft. Please post pictures as you build and when you launch. It is a lot of fun for us to watch you build your project and fly it. If you get the urge to try other tube fin rockets, try the LOC Precision Cyclotron. It flies well on anything from G64 to H200+.

 

[JimiB]

Well this has certainly taken me longer than expected. Seem life gets in the way of rocket building - I'll have to fix that.

I have managed to cut the four tube fins, lightly sand, fill a bunch of spirals and sand again. Oh, and I used my new dremel that my wife bought me to cut holes to fit the "squiddly" little fins into the nose cone. It looks pretty cool when I fit it together with a little green tape to hold it.

But looking at the rocket in it's fitted together state I have a question. My club (Austin Area Rocketry Group - AARG.org) encourages the use of rail launchers for all HP flights. Looking at the space between the tube fins I see just barely 1 inch clearance. (See photo.)

Has anyone launched a King Kracken on a rail? If I install with standoffs to get the clearance, how much of a standoff could I use?

I'm going to do some actual in person measurements before I build but thought I would check with experts here as well.

 

[Rainmaker]

Well this has certainly taken me longer than expected. Seem life gets in the way of rocket building - I'll have to fix that.

I have managed to cut the four tube fins, lightly sand, fill a bunch of spirals and sand again. Oh, and I used my new dremel that my wife bought me to cut holes to fit the "squiddly" little fins into the nose cone. It looks pretty cool when I fit it together with a little green tape to hold it.

But looking at the rocket in it's fitted together state I have a question. My club (Austin Area Rocketry Group - AARG.org) encourages the use of rail launchers for all HP flights. Looking at the space between the tube fins I see just barely 1 inch clearance. (See photo.)

Has anyone launched a King Kracken on a rail? If I install with standoffs to get the clearance, how much of a standoff could I use?

I'm going to do some actual in person measurements before I build but thought I would check with experts here as well.

View attachment 358448

If we fly next weekend, you could bring it out and do a test fit.

 

[Thorfire]

My son built a cyclotron for his 1M cert flight. A 10/10 rail fit through one of the tube fins (with standoffs under the rail buttons).

 

[JimiB]

If we fly next weekend, you could bring it out and do a test fit.

Good idea. If I can make this weekend's launch I'll do that. Not sure if I can be there - maybe mid-day only.

 

[JimiB]

My son built a cyclotron for his 1M cert flight. A 10/10 rail fit through one of the tube fins (with standoffs under the rail buttons).

I had wondered if that might work. Good to know it's been done.

 

[HandsomeRob]

I have nothing to really add to this, other than to say "hey!" to a fellow AARG member and also, good luck!

Hope we can have a launch soon, last one was rained out, and this coming one might be stopped by a burn ban. Argh!