Hello all,
I was given a used APM 1.4 by a friend (who moved to a Naza some time ago) with a new Flamewheel 450 frame (only frame no motors). As I had 4 brushless motors and 30Amp ESCs and 2 sets of 10x4.5 props I decided to assemble everything. I flashed the latest supported firmware for the APM (3.2.x I believe) as suggested by the latest Mission Planner. PIDs are default. I had to disable the magnetometer check as it wasn't working as reported unhealthy (I ordered another: powering it with my bench PSU I get no data from the SCL or SDA IIC lines which it should output shortly after reset). I calibrated the accelerometer successfully though. Long story short, when (in stabilize mode) I lift off and hover about 3 feet off the ground (more in this state is pretty risky!), the first 3-4 seconds are ok but the more it hovers the more it starts tilting backwards and drifting in that direction and I if I don't land it will eventually drift off unrecoverably. The commands are responsive at first then apparently become sluggish and unresponsive. I have it's GPS connected but it makes no difference with or without as the only thing that should be relevant in this mode and situation is the really accelerometer. I don't think the fact that the magnetometer is removed makes a difference either. The APM is on 2 layers of thick silicon adhesive and is very stable. There are no noticeable vibrations in flight.
Does anyone have any pointers as to why it starts drifting more and more out of control always backwards? I can hover at max 10 seconds before I need to cut throttle and land. As I said, as soon as I throttle up and hover around 3 feet it seems ok and responsive, but the more I hover the less it becomes responsive and starts drifting backwards more and more and I am unable to correct it.
Thanks!
P.S. I might buy an APM 2.6 at this point as I already have the GPS and the rest of the gear, I'm sure it will be performing better!
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