Hello everyone.. if you could just give me some advice on this i would be grateful.. So here is my problem:
When designing my octocopter, I figured out what size of ESC to buy based on ecalc.ch calculations. They say for my exact current built that the max going through a single motor will be 8.63 Amps. I have 30 Amp ESCs, so I am assuming that should be PLENTY of room for safety.. Though after flying for just 2 minutes, the ESCs are way too hot to touch, and actually a few of them melted the double sided sticky foam i used to secure them.. I have no idea why they would get so hot from so little current based on their "max" current.. I almost bought 15A ESCs, but thanks to some gracious advice from a member on DIY Drones, I bought the 30s. They are Turnigy Multistar 30A ESCs.
Attached is my Ecalc page.
Thank you so much!
Replies
Hi There
Are you using 4S packs?
I had exactly the same issue with those ESCs. I initially ran 3S lipo packs and although my motor's did not nearly pull 30A each, the ESC's became warm to the touch after a 10 minute flight. Not a big issue there. I then decided to upgrade to 4S packs since the spec sheets says the ESCs suppor 4S.
After doing that and calibrating the ESCs again, the ESC run so hot after 2 minutes of flight that they overheated so badly that they shut down and my craft fell from the sky. I did some reading and on RCgroups there was a post about the Multistars that did not really support 4S pack.
I tried various settings mentioned on RCgroups and did a couple of test flights, but had no success. During my last flight with them, they overheated again and caused the craft to fall once again. This time I was close to ground and nothing got damaged. After that I tried to change some more settings and one ESC failed to go into calibration mode ... i pulled of the green plastic covering and then realized the ESC is fried.
I then ripped all of them out and replaced all the ESCs. According to me the Multistars are CRAP!
Hello Johann, Thanks for the quick response.
Yes, I am running 4S lipos... I had no idea that could affect it, considering they are supposed to work with 4S.
I have only flown for at most 2 minutes at a time, and I noticed on my last flight as i was coming down for a landing one of the motors completely stopped 10 feet off the ground and it started to tilt , so i had to drop it from about 5 feet. Luckily I just rebuilt my frame with 1 inch aluminum so that was not problem for it.
So you have replaced them all now? What ESC did you go to?
Hey
Yea I replaced them. I put these in <link below) and I'm VERY VERY happy.
After 10-12minute semi aggressive flying on a 4S pack, I can barely feel any change in temperature on the ESCs. I have been flying with them for just over 6 weeks now and have not had a single issue.
ZTW Spider 30A
Calibration on my APM2.5 was a breeze. They are MUCH more responsive that my MultiStars.
They are a little pricy at 16 a piece, but well worth the investment. Im buying 8 of these as we speak. Thanks so much for your help!
No Worries
You can also look at the Afro's. They are also awesome. Only reason I did not buy them is I could not get them in stick in South Africa at the time I needed them so I went for the "next best"
Keep me posted on your upgrade and please let me know what you think of them once you added them to your bird.
Have a good one