Does anyone have any experience using a electro-permanent magnet?

Hey guys! I’m still waiting for my Navio+ but in the meantime, I was looking for some mechanism for lift objects with my drone…

I found this interesting thing, the EPM688… http://copter.ardupilot.com/wiki/common-optional-hardware/common-electro-permanent-magnet-gripper/#connecting_to_a_pixhawk

Do you have different ideas or recommendations? I will be happy to hear it!

I do not own the EPM, but Arducopter on Navio+ drives all PWM outputs at 490Hz, as far as I know.
The EPM only accepts PWM signals with 50Hz.
It is not possible (at the moment?) to change the pwm rate for selected outputs.