I have a DJI F550 hexa running AMP2814 motors with 11"-4.7 props and 30Amp esc's. I have a full FPV setup with transmitter, 600TVL camera and gopro hero3 using a 3S 5000 battery. After 5 minutes of hover the esc's are hot as in uncomfortable to where you can only hold your fingers on them for a short time. The hexa weighs in at 6lbs 9oz. And the motors have a max thrust of 2200g at full throttle per motor. The motors are pull 15Amps each.
Hot speed controllers
- Thread starter Chalagi
- Start date
gtranquilla
RadioActive
Motor startup current can peak around 200% of the normal running current..... 11 inch props are too big for the 30amp escs. Also you are carrying too much payload weight for these Escs. Ecalc for MRs will tell you that if you input your data correctly. Invest in 45 amp Turnigy Multistar ESCs or equiv and your issues will disappear.....
Then why do other folks that are running the same setup don't have this problem. And some have copters that weight upwards to 10lbs and are running 12" props. Doesn't make any sense. One guy is running a carbon core 650 with the DJI opto 30Amp esc's and 12 inch props and no problems. But I do think that I need at least 40Amp esc's even thou my motors are only pulling 15Amps each.
gtranquilla
RadioActive
IMHO - there remains several possibilities........
a) Motors and ESCs get hotter and hotter as airtime increases (normal)
b) sudden rpm corrections drive up current demand..... smooth running hover keeps current demand lower.
c) g force increases rapidly when recovering from downward travel...... MR weight due to downward momentum doubles and triples.
a) servo frame rate too high..... switch from high speed to normal speed (configure your receiver for lower frame rate)
b) ESC hardware simply not compatible with MR controller
c) your flying altitude and air temperature are significantly different from those you are comparing with
d) C of G not at the center of your MR airframe (some motors carrying too much weight relative to the others).
e) ESCs not correctly configured to be compatible with your MR controller.
But in summary you still have a lot of weight on a F550 airframe and the 550 mm restricts your options to use larger, slower motors with longer props which is always more efficient.
a) Motors and ESCs get hotter and hotter as airtime increases (normal)
b) sudden rpm corrections drive up current demand..... smooth running hover keeps current demand lower.
c) g force increases rapidly when recovering from downward travel...... MR weight due to downward momentum doubles and triples.
a) servo frame rate too high..... switch from high speed to normal speed (configure your receiver for lower frame rate)
b) ESC hardware simply not compatible with MR controller
c) your flying altitude and air temperature are significantly different from those you are comparing with
d) C of G not at the center of your MR airframe (some motors carrying too much weight relative to the others).
e) ESCs not correctly configured to be compatible with your MR controller.
But in summary you still have a lot of weight on a F550 airframe and the 550 mm restricts your options to use larger, slower motors with longer props which is always more efficient.
I have arm extensions that will allow me to use up to 14" props. And the motors are rated for the heavy lift copter. As far as "Hot" esc's I can keep my fingers on them but its very uncomfortable. I will be switching to the carbon core frame with 40Amp esc's soon so that may make a ton of difference.
mbsteed
aerial video centric
I use 30 A ESCs on 5Kg octo HL, 12 inch props, because that was recommended in these discussions - I would have gone with 40 A (safer option) but at the time there weren't a lot of options. My ESCs do get hot but I think that is normal. If they get hotter than what you can hold then that might indicate that you are stressing them out. I have one that gets that hot but it hasn't caused problems yet.
helloman1976
Ziptie Relocation Expert
Answer these questions
1. Does your copter hover at 50% throttle in manual mode?
2. 6lbs 9oz is pretty heavy and with a 3S battery it's pulling major amperage to keep those 11" blades spinning which is why they are getting hot. Have you tried 10x3 DJI props with 4S? You'll pull less amps which means less heat and gain efficiency.
3. Is the craft oscillating from side to side quickly or anything even remotely like that? Is it flying in heavy winds?
There's your problem right there in your OP. Stop hovering so much. Fly the thing around for 5 minutes, I bet your ESC's don't come back nearly as hot.
helloman1976
Ziptie Relocation Expert
Yeah, I don't think that's it though. I think the main problem is that he's overloaded and/or the bigger props have those motors overworked. If he's not hovering at 50% in manual mode then something is wrong etc...if he's hovering at 80%, he's way overloaded etc etc. I hover for 15 minutes 2-3 times a week just practicing and my motors and ESCs come down barely warm. If I ram the throttle from zero to max and have the thing going up and down as fast as I can then they will get warm but never hot.
gtranquilla
RadioActive
Hence the reason for Ecalc for MRs...... a poor substitute for intense engineering level design of these but better than trial by error which can result in a man cave full of useless parts. Also the experience of others can be helpful if it is from reliable sources.