Mighty Mini Mitsubishi A6M Zero

After Flitetest released their Mighty Mini Corsair and Mustang last week, I really wanted to build one.  However, I'd just purchased a UMX Micro Corsair for indoor flight, and there are lots of Mustangs out there.  I decided that the other side of the warbird picture was sorely lacking and in need of some attention.

Decided to build a Zero that will be swappable with the Mighty Mini Power pods. It was a close call between the Zero, Fw-190, and Ilyushin-2.  I wanted to have something that could be combat capable, within the same size range as the other mighty Minis, and able to use the same electronics.

I watched the flitetest build videos for the Mighty Mini Warbirds, and took a close look at the plans and saw several innovations that could make my design easier to build.

Going from an idea to the above picture isn't actually that complicated if you use the tools available on the net and the massive amount of information to be had from Flitetest and the forums.

My first step, other than the vague idea that I wanted to build a Zero was to track down a decent 3 View image.  10 Seconds on google found me this:

Next I tracked down PDF copies of the Flitetest warbird plans, and a bunch of Zero pictures for inspiration. By the time I'm done designing a plane I have a pretty good story board going.  Just about any graphical drawing program will work for plane designing.  I happen to use DoubleCad XT as it's free and very easy to use without a lot of clutter.

Here's a current screenshot of my Plans and all the stuff I used to get there:

 My third step, if I'm counting right was to match the 3 views size to my wingspan goal and then start tracing and taking measurements.  Building with foam starts out as a 2 dimensional process and tracing things will get you a very long way.

Using the tracing, as well as taking measurements off of Flite Test's plans for things like servo cutout sizes you end up with something like this:

Monkey see, monkey do.  Flitetest has made things simple, you can get a lot done by using their example.  The rest of the process was pretty straight forward.  Draw up all the pieces you need, cut out the pieces and start trying to assemble the plane.

There were two things about the Zero that made things a little difficult for me.  First off, the nose is very short, which made it hard to fit everything in place to achieve a proper balance point.  My first prototype was destroyed in seconds when I tried to fly tail heavy.  It's all part of the fun.

Second, the Zero tail is a bit oddball compared to the other Flitetest designs.  The elevator is forward of the rudder, and only the section of rudder above the elevator is functional.  I solved this problem by building a split elevator.  A piece of wire and some strategic foam removal....

The key here is to keep going.  After I destroyed my first prototype I did a bit more research to figure out where the CG should be, and then modified my plans.  I stretched out the nose, used a bigger motor (the prototype had a tiny one much smalled than the Flitetest F pack), used a bigger esc and still had to add a little nose weight.

Here's the result:

It did remarkably well in the high winds. Wind a pretty steady 14 mph without much gusting which helps. Thought I was still tail heavy at first, but that was just the wind and being out of trim. Roll rate is pretty crazy, but it's very stable in the air, probably as a result of the Zero's high level of dihedral.

It's also much faster than I expected it would be. The 2206 2150kv motor and 6045 prop put out 610 grams of thrust, which is a whole lot for such a small plane.

And after a successful maiden, you need to test the limits of your machine:

I'm pushing the limits of my thumbs more than air frame here. During lunch break at work today I took the plane out to take advantage of the calmer air. It was handling very well, the two crashes in the video were my fault. I tried to do a barrel row down the tree line and used too much rudder the first time, and the second I purposely stalled it to see what would happen and got caught up watching it fall. When I punched the throttle, it went from full stall to tip stall....

Makes me wonder if I should go slightly away from scale on the wings and make them more friendly for lower speed performance. I'm torn between that, and not losing the handling it has now, because the flight experience is excellent when you keep your speed up.

Any opinions?

Right now it's quite stable, very responsive, and inverted is excellent. I need to build and fly the Corsair and P51 to see how they handle.

We'll have to see how this goes.  If you have any opinions I'd like to hear them.

You can follow the build more closely, take a look at the latest beta plans, and see detailed build instructions here on the Flitetest forums.

http://forum.flitetest.com/showthread.php?23703-Mighty-Mini-Mitsubishi-A6M-Zero-Swappable-Build-Thread

Keep in mind that the plans as they stand aren't perfect.  I have a few things to tweak before the final non beta release.  If you still want to build one now, the plans will get you there, and I'd love to hear how things went for you.

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Final Plans are out.  Thanks everybody for you comments and suggestions.

Mighty Mini Mitsubishi A6M Zero v1.0 - Full 

Mighty Mini Mitsubishi A6M Zero v1.0 - Tiled