Help! Major trouble with EZ first flyers

[ToeMoss]

Hi, I have been working with my local school building the EZ first flyers plank with the 5th graders. Yesterday we finished the planes and went to fly them, and we had some issues. I have run summer kids programs with the EZ flyers before and not had these issues. All but one of our planes did a hard nose dive. As soon as they left the throwers hand, they would dive straight into the ground. Why would it do that? I haven't had this issue before. I checked and double checked the planes. All of the electronics are set up correctly. I adjusted the flaps higher and it helped some, but I have them where it is recommended, and I have not needed to put them higher than this before. If it was just one plane, I would be more inclined to think that this plane is an anomaly, and crank them way up. However, since they were all doing it, I thought I might be missing something else.

I will attache pictures of the plane that I built.


Any help will be much appreciated.

 

[LitterBug]

Props reversed? CG too far forward?

 

[ToeMoss]

Props reversed? CG too far forward?

The props are on correctly. I can feel the wind from them pushing the plane forward. The CG is pretty good. The plane sits level, so if anything I could add some weight to the front.

 

[toryander]

The props are on correctly. I can feel the wind from them pushing the plane forward. The CG is pretty good. The plane sits level, so if anything I could add some weight to the front.

Did you ever figure that out?

 

[Bjohns67]

Same issue with me. I do this every year with 30 9th graders in my Technology Engineering class. Usually they fly great - this year mostly duds.
What I learned was:
1. I need to buy new electronics (without the controllers) each year. The crashes they take can damage one motor and it never spins the same as the other motor.
2. I made a poster that shows which direction the props must face - letters towards or away from the motor. That helped with some of them.

Mostly, even after V2, we still need more POWER and lighter planes for these to really soar.

 

[AIRFORGE]

The #1 problem I've noticed when people fly EZ planes is they lower the throttle to zero while flying. As soon as they do that the plane has no controls.
The THROTTLE MUST ALWAYS BE ACTIVE for the gyro, stabilizer and controls to function. A minimum of ~5% to 10% is needed for it to be controllable.
EDIT: I should add that about 90% of the pilots did not know how the EZ boards worked or that a little throttle was needed for control.

 

[L Edge]

Same issue with me. I do this every year with 30 9th graders in my Technology Engineering class. Usually they fly great - this year mostly duds.
What I learned was:
1. I need to buy new electronics (without the controllers) each year. The crashes they take can damage one motor and it never spins the same as the other motor.
2. I made a poster that shows which direction the props must face - letters towards or away from the motor. That helped with some of them.

Mostly, even after V2, we still need more POWER and lighter planes for these to really soar.

A) As for the motors and one never spins the same as the other, there are a three things that can happen.

First, in the crash, check if the prop backside is binding against the blue or red frame that hold the motor.
Second, one of the prop blades make be ground down(due to throttle not shut down on crash) so you will get oscillations.
Third, the prop shaft gets slightly bent so it never runs the same due to oscillations.

By the way, save the crashed spare good motor and match with another( reverse wire if same color motor) and use if lacking funds.

2) agree with.

3) Actually for the tech class, the V2 set is an excellent tool. The electronics weighs about 27.8 grams and most planes can fly under 55grams if designed right. Isn't that the purpose of the engineering class, to build something within the limitations? Some will pass, some will fail.