Hi,
I had my first flight test of my new DJI F550 build yesterday. It's an F550 kit with Naza V2, E300 propulsion with stock 9.43inch props, iosd mini, ImmersionRC VTx, FrSky X8R Rx, AeroXCraft landing gear, Zenmuse H3-3D gimbal and GoPro HD Hero 3+ Black. Power is 4S from a Zippy Compact 5800mAh 25C battery.
Weight is about 2kg excluding gimbal and gopro.
During testing in gig left the gimbal and gopro off so the flying weight was 2kg, it took off perfectly and was very responsive, I was monitoring voltages using the feed from the iOSD Mini.
There re seems to be some big voltage sag going on, after a bit of use with the pack sitting at 15.3v when I start the motors the voltage dropped to 15.1, then on take off with full throttle and forward pitch, it drops to 13.9v trigger the voltage protection (set at 14.8/0loss and 14.2/0loss respectively). I charged the pack after that and it took 2700mA according to my balance charger, so it wasn't even 50% depleted and slightly warm to the touch after flight. I'm thinking that this level of sag must be an indicator that something is wrong? I'm using XT60 connectors which I guess could be a bottle neck - I'd imagine maximum current would be 15A (rating of E300 ESCs) x 6 so 90A way above the rating of XT60. I also found them pretty difficult to solder onto the big gauge wires on the LiPo so I guess that the soldering could be an issue. The battery at 25C 5.8Ah should be able to deliver a constant 145A so don't think that's the issue.
Any ideas?
thanks,
FJJ
I had my first flight test of my new DJI F550 build yesterday. It's an F550 kit with Naza V2, E300 propulsion with stock 9.43inch props, iosd mini, ImmersionRC VTx, FrSky X8R Rx, AeroXCraft landing gear, Zenmuse H3-3D gimbal and GoPro HD Hero 3+ Black. Power is 4S from a Zippy Compact 5800mAh 25C battery.
Weight is about 2kg excluding gimbal and gopro.
During testing in gig left the gimbal and gopro off so the flying weight was 2kg, it took off perfectly and was very responsive, I was monitoring voltages using the feed from the iOSD Mini.
There re seems to be some big voltage sag going on, after a bit of use with the pack sitting at 15.3v when I start the motors the voltage dropped to 15.1, then on take off with full throttle and forward pitch, it drops to 13.9v trigger the voltage protection (set at 14.8/0loss and 14.2/0loss respectively). I charged the pack after that and it took 2700mA according to my balance charger, so it wasn't even 50% depleted and slightly warm to the touch after flight. I'm thinking that this level of sag must be an indicator that something is wrong? I'm using XT60 connectors which I guess could be a bottle neck - I'd imagine maximum current would be 15A (rating of E300 ESCs) x 6 so 90A way above the rating of XT60. I also found them pretty difficult to solder onto the big gauge wires on the LiPo so I guess that the soldering could be an issue. The battery at 25C 5.8Ah should be able to deliver a constant 145A so don't think that's the issue.
Any ideas?
thanks,
FJJ