Flying and then motors stop...

[step...@shenandoah.k12.ia.us]

We have been practice flying the past couple of days.  Today we hit a snag.  When we are throttling up the motors everything powers up like it should and then before it lifts off the ground, the motors stop turning.  Is there something wrong that we need to address?  What might be causing this to happen?  Any suggestions?

[Dr. Huett]

This is weird. If you can, post/send a video of what is happening. 

When you throttle up you will start to pull a lot of current from the batteries. My first guess would be the battery.

A couple of things you can try:

Make sure the battery is fully charged. 

Use a different battery

Balance the battery. The battery charger that was sent out has a balancing mode. The battery itself contains 3 cells. In balancing mode it makes sure that all the cells charge up to the same voltage.

Second possibility is that the trim offset on the controller got moved. You can use the vertical trim switch to adjust the offset on the controller (see attached picture).