I just dusted off my old xk x251 and set it up on my jumper v2 plus. After setting the channels to switches, channel 8 is what turns the gyro on and off. The stock transmitter limits it to stagility mode i think that just flips the quad over if it goes past a set pitch or roll. However, with the jumper transmitter, it is in full acro mode (as far as i can tell from the first flight) when the gyro is turned off. I hadnt heard of anyone else trying this so thought id share and see if we can give some new life to this old quad.
If there is a way to increase the rate speeds, especially the slow yaw rate, the x251 would be an awesome true acro flyer.
