My "Corro-Kraken Build Thread

rcgreaves

Member
So I've been enjoying flying wings since 1999 when I had one shipped to my hotel at a trade show in Vegas. Im not a gambler and a week in a hotel for me isn't about the town or even the theatres, but what to build on that second bed! I built a Zagi 400 and Chip Hyde even flew/signed it at the TOC the following weekend. It paid to plan my show attendance dates accordingly.

So my FT wing experiences have been great too. My son and I enjoy our Mini Arrows, but only a few plops in our less than groomed high grass and the noses collapsed far too easy. For us the whole fun of wings is fly where you are.

To some extent, the nose crush problems on all Dollar Treem Foam fliers could be minimized with what I term "an ejecto-chute" a block of EPP under the battery with a 45 angling cut in front of the battery attached ONLY with flat velcro-no strap. in the event of an abrupt stop, the velcro releases. There is a science to this..less velcro can be more..and the mass of the battery contributes less...to the shattering of the foam nose. In truth, my EPP Zagi nose is still intact on retape # infinity... Note that experience taught me to tether my ESC wires back with zip ties so the shock of separation doesn't rip the wires out of the ESC. Castle Creations stock investment- a good idea..

So I started recently to think about how to improved mini arrow/Kraken durability.

About a year ago I visited a sign shop and walked out with a 4x8 sheet of 2mm Coroplast fluted vinyl sign sheeting. "$20 left over, you bet I'll buy it"....Then, It languished in a corner, my wife even used it as a blotter when staining a table...But with the cold blast in the midwest this past week I broke out my Kraken plans. With the landing gear the Kraken isn't so vulnerable, but I've had sooo many small wings, Zagi Razor, Arrows etc, and hey, I have enough material for a Kraken right? Weight savings is not a big priority with this design. I slope soar too, the Big M hill in Platteville WI is visible from my yard-so a huge "mother ship" for sloping has always been on my short wish list, not to be confused with my tall wish list. I'm short so that's nonexistent.

A few build details:

The corroplast to foamboard bond on the spar box is fiercely strong. I wiped the corro with laquer thinner to clean off release agents etc.

I added a couple lengther of carbon fiber. a ridgid tube on the leading edge to add vertical dimension to the leading edge of the air foil, and some added but seemingly unnecessary rigidity.

I plan to slope with this so I added a square carbon fiber tube that spans and ties to the foam core box spar. I didn't want to discover after folding that the corroplast would permit a flexy spine. This triangulating spar did the trick.

Servos. Kudos to Bixler, but 9gram servos even metal gear versions just aren't my speed..literally. All my other wings struggle to get the C/G forward, but with the tractor motors that's just not going to be an issue here. I opted for standard sized MG servos installed on their sides.

So that's my build progress report. My wiring harness is done...Man buy that $9 power harness from FT my soldering iron got a major work out heating 13g wires. Honk on those connections to be sure they are not "cold soldered

For sloping it occurs to me I can remove the swappable pods...it might be worth the extra effort to attach my landing gear with brackets just so I can plop this one in the grass to prove my point about having built a more durable nose.

Cheers!

PS Flite Fest 2018 was a highlight of my family's year. We spent a week at Air Venture, I earned my PP in 2018, but Flite Fest in OH despite the heat was a great memory. Thanks all.
 

rcgreaves

Member
Merrixs recently queried how the Corro Krakken has held up. His question didn't post here so I'm attaching it with my thoughts. 2mm makes an excellent bottom skin choice on a Kraken.

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Merrixs greetings from SW Wisconsin. I received your query about my Corro Kraken. Oddly your question didn't show up in the forum thread. I'll reply here and paste both on the thread ok?

So the Corro Kraken proved extra durable when my Spectrum gear did an untimely brown out in 2021. I stuffed it vertically from 100' plus. Along with the corro leading edge fold, I embedded CF rods that largely weathered the crash intact. One narcelle collapsed and required a rebuild. To bind servos to corr I highly recommend a combo of hot melt, a thin ply backing plate and most importantly double zip ties that perf the corro. I combine two ties with the joiner forming on a corner of the servo for a snug fit indeed. Belly landing with tractor props has never been a success for me. Trick RC once released a twin Zagi 400 that taught me some tricks, primarily that pusher motors only work with the motors forward of c/g. I struggled long and hard and required the patience of a teen to program throttle mixing so I will be slow to relinquish the stock motor set up. That said- a center pusher zagi 400 style would by my thought for an alfalfa field belly landing. Maybe an investment in twin folding props would enable a simpler migration to no l/g operation. On the slope the Kraken is awe inspiring. Over my 30 years of modeling I've pined to try sloping the "mother ship" flying wing. The Kraken in corro top and bottom would be a tough cookie. Contact me directly should you wish further inputs. Happy Independence day. God Bless you Bix and all my FT brethren!
 

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