Help! Simple Cub Takeoff/Power Problem

[Crutchy]

I recently built the FT Simple Cub and painted it. I tried taking it off and it seems that the B Motor, battery, or propeller (don't know which) is causing the airplane to not be able to take off. At first I tried to take it off, and it drove on the ground, but didn't takeoff. Then I tried to hand launch it, and it did just a straight nose dive in the ground. The propeller broke, so I replaced it. Had the same problem the next day with it not being able to takeoff. Any suggestions? Should I change to a C Pack? Bigger battery? Bigger propeller? All of the above? Anything will help!

 

[LitterBug]

Trim it with more up elevator. sounds like it may not be balanced out and have too much nose weight.

 

[Matthewdupreez]

Check that your control surfaces are traveling the right way... When you pull down on the elevator stick the control surface should move up.

 

[Crutchy]

The control surfaces are fine. I don't have as much left rudder as I would like, and i will probably have to replace the push rod for that (I'm getting a little bit of flex). I think that the plane is actually slightly tail heavy. I tried to balance it a couple days ago, and it wouldn't even move, so I tried to just fly it without the weights, and it wouldn't takeoff. It might seem like an obvious solution, but I'm sort of new to this hobby and I'm not sure what to do.

 

[Matthewdupreez]

The control surfaces are fine. I don't have as much left rudder as I would like, and i will probably have to replace the push rod for that (I'm getting a little bit of flex). I think that the plane is actually slightly tail heavy. I tried to balance it a couple days ago, and it wouldn't even move, so I tried to just fly it without the weights, and it wouldn't takeoff. It might seem like an obvious solution, but I'm sort of new to this hobby and I'm not sure what to do.

Could you post a video of how it balances?

 

[LitterBug]

If it nose dives when you hand launch it, you either have too much nose weight, not enough speed so it is stalling, or not enough up elevator.

 

[Crutchy]

It is not letting me attach my video for some reason

 

[quorneng]

Crutchy
You have to download your video onto You Tube or similar. Once that is done you can use the link button (or Ctrl K) to load the URL of the video on that site.

 

[Crutchy]

Here is how it balances. I thought it was more tail heavy, but I actually think it's right on level with may a hint on nose heavy: https://youtube.com/shorts/RVmIQ60NneQ?feature=share
Here is how much elevator deflection I have:

 

[Tench745]

A little hard to tell from the video, are your fingers on the CG marks from the plans? Your plane is balancing a little tail low in the video.

Another thing to check is that your prop is on the correct direction, and the motor is spinning the right way. The numbers on the prop should face forward, and obviously, it should be blowing air back over the plane.

 

[Crutchy]

Yep. My fingers are in the right spot. I have a few glue drops over them so I can find them easily. And my prop was facing the right direction. That's the first thing i checked, so I know the direction isn't a problem.

 

[Matthewdupreez]

Here is how it balances. I thought it was more tail heavy, but I actually think it's right on level with may a hint on nose heavy: https://youtube.com/shorts/RVmIQ60NneQ?feature=share
Here is how much elevator deflection I have:

Are you applying full up elevator when you throw it or takeoff??
If so you could be stalling the plane, I do think you've got wayyyy to much up elevator throw.,.
I would adjust your throws if you can... Use the throw gauge that's included in the kit... And use low throws

 

[Matthewdupreez]

You could possibly also have down thrust on your motor by accident...
That could cause it to not takeoff.....
Because the prop+motor is pulling the nose down...
If you look at the motor, it should be perfectly parallel to the wing, if not you've got a problem.

 

[Crutchy]

The wing and motor are parallel. I've tried using as little elevator as possible, and using as much as possible. Not sure why it's not working.

 

[Matthewdupreez]

Try trying to take it off and record a video of it, then post it here..

 

[Crutchy]

Okay. I will. It might not be for a day or 2 though.

 

[Crutchy]

I also need to oder new propellers. On the store, there isn't any 9×4.5 CCW props, so would I be okay getting a 10×4.5 CCW prop?

 

[Matthewdupreez]

I also need to oder new propellers. On the store, there isn't any 9×4.5 CCW props, so would I be okay getting a 10×4.5 CCW prop?

No not on a b power pack...
Try ordering from a different store, and if you want one that'll last just about forever get an APC. I've crashed mine really hard five times and it's still perfect

 

[The Hangar]

No not on a b power pack...
Try ordering from a different store, and if you want one that'll last just about forever get an APC. I've crashed mine really hard five times and it's still perfect

10” prop is totally fine on a B pack. I’ve done it many times and the motor doesn’t Have any problem with it.

 

[Matthewdupreez]

10” prop is totally fine on a B pack. I’ve done it many times and the motor doesn’t Have any problem with it.

Oh... Ok ..
I didn't realise that it could work...