First I really wanted to put the word out about Hifei, who makes the King Kong ESCs (also Turnigy SuperBrain ESC's). I knew going into this project it would be a mess since a lot of things in our hobby are not standardized in the least bit yet. I already have encountered a few problems that left a sour taste in my mouth, mainly with manufacturers not willing to even respond to simple questions. Not sure if it's just me but it seems more than a few of the "big guys" in our hobby have elitist attitudes when it comes to dealing with the public, and always have the "your just one person, we don't care" attitude...you don't really see that in the mainstream corporate world. That said, this hobby is exploding so fast that I have to give them some slack as a lot of these companies went from a person or two in a garage to factories and warehouses in a matter of months.
Anyways....after seeing all the crash threads on here it seemed the biggest similarity was an abundance of crashed for undetermined reasons. Even flying my first quad I had a few motor/ESC cut outs and all I had to go by was my memory of which arm dropped out...hit or miss at best. Gets even worse when you go FPV and can't see (or hear if your using telem) your MR when it does down. It seems while we keep getting really cool features like RTH, IOC etc, it seems data logging is always left out for the most part...I know OP and the big money systems have it, but mainstream hobby flying it seems to be lacking quite a bit. When I saw the King Kong with the data logging capability I knew it would be priceless to be able to see each individual motors specs (Amps, Watts, Volts, RPM, Temp, Throttle Position) after a flight to see if your wires are big enough (voltage drop), props are right (Amps and RPM) etc...and especially important after a crash to immediately rule out or pinpoint an ESC or motor failure. I am building a heavy lift Hex so I bought 6 60A King Kongs (had to go with 60A because that's the smallest they make besides the 45A that was out of stock, that can handle 6s that the motors require) along with theTurnigy 4830 480Kv motors that would be controlled by DJI of course. When I got them I had issues connecting them to my PC and they seemed bricked....one email to Hifei and I had a response in 10 minutes with some attatched new firmware and instructions/apologies for the issues. Got them all working great...then remembered the DJI stuff is picky when it comes to ESC's when it comes to throttle travel and refresh rate. Knowing these ESC's are tailored for helicopters I emailed Hifei again about my concern of compatibility. They let me know they now offer two ESC's that support 400+hz rates but when I checked they were only 3s versions, no 6s yet. I asked them what I should do with $300 worth of ESC's that might make my hexa fly away on me....about 2 hours later I had a custom firmware in my inbox tailored just for my 60A 6s ESC's! I wasn't expecting that AT ALL since every other time I've contacted manufactures about issues like that I either got no response at all or a simple "we don't care" type of response. Tons of kudos to Hifei and anyone who wants what I want (complete data logging of each motor) definitely check them out!
Now to the prop testing question....I've never done any prop testing before so I'm not sure what is normal and what's not... the specs of the motors are 22A constant, 31A max @ 25v, 680w max. The suggested props are 14x5-15x5...but all the discussions about them said that they could handle much more if needed up to 17x5.5, and according to eCalc 15x5.5 wouldn't be an issue so I went with 15x5.5. I got one motor/ESC wired up to the throttle channel on my Rx and a 8Ah 6s battery...proceeded to calibrate throttle then ramped it up to full throttle and back a few times. First impression was "holy shytttteeee"....I had a 40lb car jack sitting on top of the hex and with just this one motor spinning it almost flipped it over at full throttle! Anyways....once I did that I connected the ESC to my PC and downloaded the data and I was shocked! My max amps were 42A at 994 watts!!!!!!!! Calculated thrust at that power level is around 4kg!!! This would tell me that the motor is wayyyyyyy over propped, right? If that is so...I don't understand why Ecalc said it would be fine, and everyone talking about them said they use even bigger 17x5.5 without problems??? The only thing I can think of is simple physics in that since the prop/motor was "tied down" and couldn't move, the load was much higher than it would be in flight, so I'm seeing these inflated numbers? Not sure if I'm right though...I did a search for prop testing/motor combos etc and found some really good threads but there was tons of math and big words and I haven't dusted off my degree in a few years so I figured I would look here for a "simple" answer before delving into that techno babble.
Thanks for reading my book of a post!
Anyways....after seeing all the crash threads on here it seemed the biggest similarity was an abundance of crashed for undetermined reasons. Even flying my first quad I had a few motor/ESC cut outs and all I had to go by was my memory of which arm dropped out...hit or miss at best. Gets even worse when you go FPV and can't see (or hear if your using telem) your MR when it does down. It seems while we keep getting really cool features like RTH, IOC etc, it seems data logging is always left out for the most part...I know OP and the big money systems have it, but mainstream hobby flying it seems to be lacking quite a bit. When I saw the King Kong with the data logging capability I knew it would be priceless to be able to see each individual motors specs (Amps, Watts, Volts, RPM, Temp, Throttle Position) after a flight to see if your wires are big enough (voltage drop), props are right (Amps and RPM) etc...and especially important after a crash to immediately rule out or pinpoint an ESC or motor failure. I am building a heavy lift Hex so I bought 6 60A King Kongs (had to go with 60A because that's the smallest they make besides the 45A that was out of stock, that can handle 6s that the motors require) along with theTurnigy 4830 480Kv motors that would be controlled by DJI of course. When I got them I had issues connecting them to my PC and they seemed bricked....one email to Hifei and I had a response in 10 minutes with some attatched new firmware and instructions/apologies for the issues. Got them all working great...then remembered the DJI stuff is picky when it comes to ESC's when it comes to throttle travel and refresh rate. Knowing these ESC's are tailored for helicopters I emailed Hifei again about my concern of compatibility. They let me know they now offer two ESC's that support 400+hz rates but when I checked they were only 3s versions, no 6s yet. I asked them what I should do with $300 worth of ESC's that might make my hexa fly away on me....about 2 hours later I had a custom firmware in my inbox tailored just for my 60A 6s ESC's! I wasn't expecting that AT ALL since every other time I've contacted manufactures about issues like that I either got no response at all or a simple "we don't care" type of response. Tons of kudos to Hifei and anyone who wants what I want (complete data logging of each motor) definitely check them out!
Now to the prop testing question....I've never done any prop testing before so I'm not sure what is normal and what's not... the specs of the motors are 22A constant, 31A max @ 25v, 680w max. The suggested props are 14x5-15x5...but all the discussions about them said that they could handle much more if needed up to 17x5.5, and according to eCalc 15x5.5 wouldn't be an issue so I went with 15x5.5. I got one motor/ESC wired up to the throttle channel on my Rx and a 8Ah 6s battery...proceeded to calibrate throttle then ramped it up to full throttle and back a few times. First impression was "holy shytttteeee"....I had a 40lb car jack sitting on top of the hex and with just this one motor spinning it almost flipped it over at full throttle! Anyways....once I did that I connected the ESC to my PC and downloaded the data and I was shocked! My max amps were 42A at 994 watts!!!!!!!! Calculated thrust at that power level is around 4kg!!! This would tell me that the motor is wayyyyyyy over propped, right? If that is so...I don't understand why Ecalc said it would be fine, and everyone talking about them said they use even bigger 17x5.5 without problems??? The only thing I can think of is simple physics in that since the prop/motor was "tied down" and couldn't move, the load was much higher than it would be in flight, so I'm seeing these inflated numbers? Not sure if I'm right though...I did a search for prop testing/motor combos etc and found some really good threads but there was tons of math and big words and I haven't dusted off my degree in a few years so I figured I would look here for a "simple" answer before delving into that techno babble.
Thanks for reading my book of a post!