WIP: Swappable Piper PA-12 Super Cruiser

[thatjoshguy]

1 > It's tail heavy. Forward your CG.
2 > More bands, two like yours, and two crossed over the wings in an "X"
(#64 bands, and use alignment slats, wing to fuselage)
3 > Go back and read your entire thread again. Many of your solutions are there already, like your landing gear issues.

No offence, my brother! But it seems to me like you asked for help about many/certain issues,
and didn't incorporate any of the advice you were given?

No offence taken, so long as you keep in mind I'm a very new pilot with no local help yet I just got my AMA membership and am meeting with a local club this weekend.

The new design reduced the weight in the tail a good bit, and I thought I had the CG correct. Maybe I don't though, next time I'll move the battery forward. When I balanced it the CG was about 1/3 back on the wing.

This was my third iteration of landing gear. As I think I mentioned, I hadn't realized one of the rubber bands had broken at first which is why I hand launched it. After the first crash I replaced the rubber band on the gear and it was stable for the second takeoff from the ground.

To rule out a loose wing entirely, I have gone ahead and glued the wing onto the fuselage for my next flight. If that corrects the yaw/roll, then I will know for certain that it was the issue and can work out a better mount with rubber bands or something. I have made certain that the wing is straight as well. between the servo wire extensions and Y cable for the ailerons I can make my connections without removing the wing anyway.

I'm listening!

 

[thatjoshguy]

I now know that the problem is not the wing, it's a poorly matched motor. Got her in the air today, longest flight so far at a whopping 30 seconds. Pretty much a total loss though. Forgot to mention, in the video posted earlier one of the props was a right hand rotating, the other was a left. It's the torque of the motor causing the roll. I know this because when I got some altitude I cut the throttle and the plane glides beautifully, but at 1/3 throttle it starts to roll in the opposite direction of the prop spin. I've still got a lot to learn. I'm considering the plans successful, but I don't have the budget for a smaller motor right now so I'm taking a break.

 

[Michael9865]

It is great that you receive constructive advice so well. (Many don't.) Nice idea to gain altitude and glide it to rule out structural issues. Keep flying and learning. Thank you for sharing. Job well done.

 

[thatjoshguy]

Thanks. Trying to stay positive. I new going into making my own plans things wouldn't be perfect, but it's hard not to get discouraged. At least the electronics are still good, and I've learned that I should put this motor on my Bloody Wonder!

 

[Jaxx]

Josh,
I think you did a great job with this project. You have definitely inspired me. I will try to get mine built a soon as possible so I can give you some feedback, and a motor/prop recommendation. Thanks again for all the work you put into this.

 

[NewZee]

Hi Josh....I watched your video, and I can tell you my Cub acted the same way! I think it is tip stalling a bit? I now launch straight and gain altitude before I attempt any turn, and then use very slight aileron try not to bank more than 30 degrees, WE have all been there (I'll be there again) we are all pulling for you, don't get discouraged! my cub which is the same size flys best on a sf 8X6 prop
see my maiden video below ...look familiar?

.

 

[thatjoshguy]

Lol familiar, yes, but yours looked better! My last flight I was using a 9x4.5 APC prop, and from what I've been reading I need to ease the throttle with this motor vs. gunning it like I usually do on the HexTronix. I've also been reading that a prop with less pitch won't have as many torque issues. I can scale up if I need more thrust with less pitch.

I'm going to try these motors in my swapable Eagle I built. The wings are HUGE (54" WITH an 8 inch cord) so I shouldn't need much throttle at all and it should be able to deal with the torque a bit better I think. otherwise I'll save them for a multirotor build later on