It was a smashing success.
Smashing because some of it got a little smashed.
Successful because there was little damage (nothing about five hours of reworking the engine mounts won't fix)
and I learned a lot.
I set Mothra down on the runway and taxied her to and fro several times. The differential thrust really controlled the thing nicely on the ground. Those two DT 750 motors spool up the 1147's without issue very quickly, quite responsive. Had to be mindful that unlike a rudder, diff thrust works only when a prop is spinning! I may program another mix for ground control where the rudder will increase throttle when the stick is down. As it is now, the rudder decreases throttle on one motor. Anyway, it was pure excitement, my first twin experience. Sounds awesome.
So, the taxiing reached a crescendo and she jumped up a foot or two and really seemed like she wanted to be in the air. Now, an experienced pilot would have done something different but I was indecisive as to whether or not I wanted to keep her up. After a moment of vacillation, I settled on bringing her back down. I must have allocated a bit too much brain power to decision making, as pilot error became a huge factor at this point. I slammed her back to terra firma. The shape of this wing puts the elevons way back and they have great influence. There's a name for that cycle of over-correction, the up down thing, but I forget exactly what that word is. Any way, hit the gear a little too hard, gear folds a little, unbeknownst to me, the prop hits the ground. Mothra took a bounce back up and I figured that would be a good time to keep her there, so I just "poured the coals on." This is about when the heretofore unbeknownst prop-ground incident entered into its new category: the beknownst prop-ground incident. Half of an 11" prop at full gas is mildly unbalanced and proclaimed as much by tearing off the nacelle.
Here's the great part, from about twenty feet up, Mothra leveled off, dead stick, and glided so sweetly into the tall grass adjacent the runway. Thank you engineer for the cg suggestion, 30 was quite nice! Only damage was the torn nacelle, and two bent gear.
Since both nacelles were compromised, I am refitting them in a more secure manner. I'm also going to braze a support or two on the gear and perhaps add some shock absorption.
Going to dial down throws and ramp up that expo a bit.
What I learned is that designing your own airplane is not always fun in the classic sense of the word, but really a great challenge, gratifying and quite exciting. Quite enjoyable. And I do think she might actually fly, certainly well enough to keep the concept and refine the design, I should think. I also learned to have realistic expectations. I was not attached to the idea that it had to fly great, there's no reason my first design should! I expected to learn from whatever happened and i did. It was awesome. Sorry, no video, I had no camera operator. I should have asked my three year old to try, it would have been interesting.
So thanks for reading, not sure if anyone actually cares about this, I know I like to read about everyone's builds and maidens, so maybe others do? Can't wait to try again. I'll take comfort in the knowledge that I have some building to do this week. I do enjoy the building. I have to get better at drafting plans, cutting on the fly, marking the foam board and trying to figure out how to get all the b and a folds measured up correctly to make the boxes for the nacelles/pods, cooks my brain. Practice will bring about myelination of my brain's foam board circuit. Neurons that fire together, wire together. That's my hope, anyway!
Ramble ramble ramble! Here's a picture of Mothra ready to go. I will need to decorate her if she flies well.
Question: I'm thinking of setting the nacelles into the wing, right above where they currently reside, glued to the bottom inside of the wing. This would allow a better bond as it will be supported by the spar and by the cross section of the airfoil. So the motors would wind up a bit higher, is this ok? Any reason that would change things for worse?
