Kraken MK III

Maingear

Flugzeug Liebhaber
This is my third Kraken. They take less time to build every time, but the time seems to pass more slowly for some reason. Still looking for the speed build kit!?!

The first was configured with a keel fairing to make the 6400mah battery aerodynamic. lost it due to a fun cub mid air collision. Plagued with ESC problems, I now use heavy duty servo extensions and 9x4.7 props.

The second one was a true workhorse. I would fly it thirty min at a time, pausing to swap batteries, and flying for another 30 min. The concept of flying from a lounge chair became a necessity. Having drinks brought to me, and mandatory restroom stops during preflight became part my SOP. I used a very large piece of Velcro to secure the battery on the belly. I left off the keel fairing because it got in the way, taking for granted the function it performed. The last flight was in very turbulent wind. App 20 min into the flight the battery departed the airframe and the plane glided at a 45 degree angle and crashed dead center of the runway. Very lucky no one got hurt! Always use a strap or tether your battery to the airframe.

Now may I present you with a work in progress, the Kraken Mark 3. It is in the final stages of construction and will sport features that do not deviate too far from its original design.

More pics to come....
Justin

 
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JamesWhom

Project Air on YouTube
That is such a nice colour scheme! I was trying to go with something along these lines with my first Versa wing. Sorry to hear about the end of your previous (mk II) one. Is this one going to have a fairing of some kind around the battery to stop another catastrophic crash? :) As Winglet said, I'm looking forward to more photos!

Best of luck with the maiden flight man.
 

Maingear

Flugzeug Liebhaber
Thanks guys! I will be using the faring. The original keel faring was held on with bunge chords. This was great protection against shock for the battery during hard landings and in the crash.

I will again mount the ESCs externally just aft of the power pod's firewalls for cooling. Finally a tail wheel will be mounted for the taxiing required at the local club. People are comming out of the woodwork as the temp drops.

Justin
 

Maingear

Flugzeug Liebhaber
MK III went down Sunday morning due to a servo failure. I had a little too much hot glue on the control surface's hinge points, they were ok until I painted them. The paint made them even more ridge combined with handling the plane by hand, it was too much for the right 9G metal gear servo. From now on I will put regular size metal gear and ensure the control surfaces are floppy, but not sloppy. :eek:

Pros:
Flight performance was incredible. Everyone at the airfield has to come up and look at it. Wing loading with 1 lbs battery has the ability to make this monster look like it's hovering in mid air during slow flight, and limitless vertical climb. 5 mph crosswind landings are totally uneventful. Deadstick finals are docile with plenty of reaction time. It settles well in ground effect and likes to have up elevator added as the speed bleeds off for brisk walking speed landings. Strong headwind allows it to hover at takeoff and touchdown.

Differential thrust is nice, but not necessary.

Counter-rotating props is recommended for stable flight in engine out procedure due to beneficial torque. As with all tailless twins, torque pushing the engine out side down is worse than no power at all. It is worth the trouble of buying the pusher prop. Single engine return to home is not a stressful event when props are set properly.

Gears are well designed and very effective in preventing prop damage.

Cons: They are petty, but you do need to know.
Battery containment is required and not addressed in the basic configuration. I recommend a keel fairing.

If you fly at a club and don't want to go "on the field" to recover the kraken after flight, install a tailwheel so the Kraken can turn. Controlling turns while taxiing is not predictable with diff. thrust. Without a steerable tailwheel in basic configuration, even then it tends to spin out. If you don't taxi, this does not affect you.

Recovering motors after a crash is nearly impossible. As the nature of the tractor configuration, they have been the first to impact every time, it is not unique to this model. The plane flies so well, that's the only way it could crash is nose/engine first. I need to go to the electric motor section of FT Forums and find a shaft source, so I can replace the bent shafts.

My next step in this platform will be a pusher blunt nose with a steerable nose wheel. Sneak peek can be seen here:

http://forum.flitetest.com/showthread.php?14396-Blunt-Nose-Kraken-Need-Your-Advise