Ultra-Micro J-3 Cub BNF

I bought this airplane at my LHS in the RTF form and not the BNF like this one. I am rating this BNF version at 5 stars though because it doesn't come with the standard little Park Zone "dual rate" transmitter, you have to supply your own TX on this version which is the best way to go.

If this were the RTF version I would rate it at 4 stars instead of 5. I'm a thumb flyer and not a thumb and forefinger flyer but with the RTF version, the only way I could control it was with the forefinger method. You come out ahead if you bind this little airplane to your Spektrum DX6i or DX5 where you have a LOT more control over the Exponential and Dual Rate functions. The PZ TX is set up for 70% / 30% in expo and dual rate and this is not enough for this twitchy little airplane.

For the first time I own a Park Zone that's better suited for indoor flying but I don't have access to a gym so I have to fly outdoors in my yard. It has to dead calm to fly this little tweeker outside. After transferring my Ultra-Micro J-3 Cub to my DX6i TX it finally became "calm" enough to fly outdoors in VERY MILD breezes. The PZ TX was just way too sensitive for me to fly with which is strange because I can fly my Sukhoi 26xp with the PZ TX on dual rate. I don't any more, but for a short while I did.

Out of the box there wasn't enough down trim to make my J-3 flyable. After running out of down trim I then took some hemostats and squeezed the "U" bend at the end of the pushrod together (but not to where they touched at the top of the "U" bend) and put my trim back to neutral and it flew then. I can actually see the negative pitch of the elevator but that's what it took to make the thing fly straight instead of trying to loop itself because the wings give it so much lift. It looks like it should slam into the ground with the large amount of down elevator it took to make it fly straight!

Then we come to the rudder... on the PZ TX what would normally turn my micro T-28 or Polecat will throw this little tweeker into a death spiral. The good thing about this is (if there is a good thing) just let go of the right joystick and throttle back and the J-3 brings itself out of the death spiral. Apply a little up elevator and throttle and you're back flying again.

Tiny, tiny rudder input is what's needed on this plane to be safe and stable. That or "mini-bump" the right joystick to turn. It's not a problem with your Spektrum DX radio though since you can adjust the expo, dual rate and servo travel.

My U-M J-3 tamed down when I took the landing gear off too. I tried it with a eRC Micro Stik 3.7v 130 mah battery also and that made it more stable except I had to "up" the speed a little because the battery was a tad bit heavier.

With the DX6i TX, loops became easier to do and inverted flight was possible too. I've tried doing an outside loop with several times but could only get 3/4 th's the way through before it rolled out to level flight. It was only after changing to the DX6i was I able to move the pushrods all the way to the next to the last hole on the control horns.

I like to climb to around 100 feet then cut the throttle and give it full left rudder and full up on the elevator and watch the death spiral, knowing that all I have to do to pull out is return the rudder and elevator to neutral then when it straightens up, give it a little throttle and "up" and get back to mischief.

One more thing, it flies using the 6mm Ember 2 motor and prop. The Ember 2 has a larger tail control surface but it doesn't react as violently as the J-3 does in a turn due to it's larger main wing. The J-3 has a thin, scale main wing which could have something to do with it being so touchy on the controls. Of the two, the Ember 2 is for a beginner while the J-3 is more for an advanced beginner to intermediate flyer.