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Spektrum flap system freeze


Active member
Question, When you pin the control sticks, are your servos making a lot of noise?
Not any more, they were initially but that changed after I went through it a second time. There have been a few iterations of this problem so far. I thought I had it solved because I couldn't get it to do it again on the bench, which is why it came to the airfield. It was behaving perfectly till I tried to actually fly it.

The old ESC has a 3A BEC, the new ESC ordered has a 3A UBEC, but that doesn't exactly matter because the plane is getting a standalone 5A UBEC before it goes back together. I just wanted to eliminate the possibility of the ESC itself being faulty while I'm in there taking everything apart. I already have to rewire the power pod, I'd rather not have to rewire it twice.


Well-known member
Not any more, they were initially but that changed after I went through it a second time....The old ESC has a 3A BEC
A 3 amp BEC will be good for about 4 - 9 gram servos. If you are moving more than 4 at the same time you are running the risk of an drawing too much power and browning out.

The servos should just about go silent when they have reached the desired position. If you pin the sticks and they sound about like they do while they are moving, you are stalling the servo. That is, the servo is trying to move but can't, because it's hitting something . The amp draw for the stalled servo will max out.

Try adjusting the end points of the servo travel until you can pin the sticks and the servos will go silent when they each the desired position. Or find out what is keeping them from moving further.


Active member
Like I said.
They were stalling, they aren't any more since I went through it a second time.
Everything was nice and clean, which is why I tried to fly it but it quit on me when I put it in the air.
It's getting a bigger ESC and an external 5A UBEC.


Well-known member
Sounds like the BEC isn't outputting the rated 3amp or something is drawing too much. The plane in the below video has a 3 amp switching BEC.

New electronics are in, new prop is on. Just lacks a battery hold-down and a re-do of the CG to make sure everything is square. Should be flying this weekend.
Second maiden flight? Second maiden crash?
We shall see.
The good news is, the control problem is officially solved. Runs like a top.
The bad news is I have the thrust angle wrong.
I taxied it around a bit, did a few ground loops and all that. It would start to pop the tail up but didn't seem to want to rotate so I did what any sensible person would do. I gave it a bunch of throttle to see what it would do. Well it hopped up into the air and as soon as I tried to level it out she torque rolled even against full opposite aileron and went into the ground like a power drill. When I got it back I sat it on the stand and looked at it, and realized that the motor has a little bit of up and left thrust angle instead of down and right. I thought I had the power pod and everything done correctly but I guess not.
So it'll come apart AGAIN and I'll see if I can get that straight.
I'll be honest, I'm really starting to get tired of screwing with this plane.
Such is life I suppose, but I'd really just like the damn thing to fly.


Well-known member
Have you throw launched it? Ground take offs are much harder when the plane isn’t trimmed. I never take off from the ground, it’s easier starting higher up already!
I usually prefer to run up and lift off, I pretty much almost never hand launch anything except big gliders. At this point I suppose it's moot until I get the thrust angle corrected.
I might try to throw it next time just to see if it'll hang without all the complexity of trying to get it away from the dirt before it wipes out. Until then I have to rip the power pod apart. I'm officially confused about that too, because it's a speed build kit plane and that should've all been fine.


Well-known member
Make sure you built the power pod the right way around. I built a mini one where I put the firewall on the flat end instead of the angled one. Also if you crash a bit the power pod bends or breaks which can throw the angles off.
If you throw it you can launch at less throttle, meaning less torque roll and you can correct a bit so you can eliminate trim from the equation. Get it up to 50+ ft before you do anything but climb so you can observe what’s happening for longer.
If it comes down to it I'll grab the plans and cut another one out. We'll see, I've got a couple other planes to work on before I dig into that one again. This one didn't even have the chance to get a couple mistakes up.
Oh well, rebuild and try again, better luck next time.


Well-known member
I am as guilty as the next at times when taking off do a long run to let the airframe get up speed and lift. Normally wing overs on take offs is usually not building enough speed to actually fly, to slow of speed renders control surfaces useless.