I’ve built a Tarot Fy680 Pro hexacopter, with Tarot 4006 620 KV motors mated to 30A OPTO ESC’s. I’m using a 3DR (not a clone) APM 2.6 autopilot, and an external 3dr GPS/magnetometer. When I apply power to the aircraft, I hear three melodic tones, followed by 4 beeps and a long beep. Then the #6 motor starts sputtering erratically - none of the other motors exhibit this behavior. I disassembled the aircraft, checked each boom individually and confirmed that it’s wired correctly and the motor spins.
After reattaching the booms to the upper chassis the problem persists. I reflashed the APM, repeated the accel, compass, radio calibrations to no avail. I then tried swapping ESC connections to the APM - for example, plugging the $6 ESC into the #5 port and the #5 ESC into the #6 port - the #5 motor sputters, so the problem seems to be with whatever is plugged into the #6 port of the APM.
Could I have a defective APM???
Here is a video I uploaded - at the time, I was suspicious that I had a defective ESC, but I’ve eliminated that possibility after further testing, so disregard my comments - just observe the behavior when I apply power:
Since this post, I contacted 3DR support. I’ve been going round and round with them - reflashed memory, sent logs, assured them that this particular APM was not involved in a crash (my hex hasn’t even left the ground!)… I even pulled an APM (a Chinese clone) from one of my quads, flashed it with the hexcopter firmware, mounted it and the #6 motor didn’t sputter. Oh, with the other (3DR) autopilot, I took my hex copter outside, powered it up, got GPS lock and was able to arm and spin the motors, even though #6 continues to sputter when I disarm the aircraft…
So, do I take a chance, cross my fingers put the aircraft back together and attempt to fly it, hoping that nothing goes awry? I’ve put quite a bit of money into this project - each motor cost $35, each ESC was $25, $150 for the APM, $80 for the GPS, $50 for the telemetry transceivers, $150 for the airframe…
I’ve asked for a replacement - will wait and see how they respond. I’ve spent the extra $$ on 3DR products as I expected that they’ve gone through better quality control - only bought a clone APM when 3DR was out of stock - lucked out with it, as it worked, though a hole for one of the screws holing the case together was stripped - I fixed it with glue…
So, after a few more email exchanges with a support guy from 3DR, I finally got him to concede that perhaps my APM is indeed defective. But there’s a problem - I ordered it along with all the other stuff for the hex back in August. I didn’t open the APM package and start using it until around November, and I didn’t get to power up until early December, when I discovered the problem. Of course, even more time elapsed as I had to take the aircraft apart, test motors individually, and put it all back together. Meanwhile, the 90 day warranty expired. So, 3DR is off the hook, and I’m stuck - just have to eat the $150…
So, I guess I’ll cross my fingers and order a $40 clone…
I ordered a Chinese clone APM 2.6 from Amazon ($40) and it arrived today. So I flashed the memory with V3.2.2 hex firmware, calibrated the accelerometer and hooked it up to my Tarot hex copter. I then crossed my fingers and powered it up - I heard the melodic tones from the ESC’s and the slow steady beep, beep… as the receiver was searching for a transmitter (I didn’t have it turned on as I only wanted to see what happens at power up). The motors all behaved as I expected - no sputter at all!
So, I pretty sure I’m over the hump. I now have to go through the compass, radio and flight modes calibration and then go through the parameters - for example, I need to set magnetic deviation to -.075… I will do this tomorrow as I’ve got some other stuff to do the rest of the day. I’m hoping that I can get the aircraft to arm and take off on its maiden flight - a simple hover in my front yard while I test out the controls and then test Loiter, Alt. Hold, etc.
Success! I had a successful test flight this morning! After completing the rest of the autopilot configurations (I had to reverse the sense on the aileron and elevator controls), I was able to arm, throttle up and take off. I hovered around a bit testing aileron and elevator control (forgot to test rudder, but I’m sure it’s okay).
When it gets lighter outside, I will go out again in my front yard and test Alt. Hold and Loiter. On Monday, I will take it to a nearby driving range and fly a waypoint mission.
The Chinese clone works. My lesson here is that I must be mindful of limited warranties on stuff I buy and make sure I try them out before the warranty expires.