Hi guys, thought I would ask the highly respectable peoples of this forum a question that has been nagging at me for a while. I built my X8 a few months ago and it was suggested to me by the dealer that all I needed was the t-motor 35A esc to power the U5 motor. However my esc temps when I land are fairly hot. I don't have any data to look at but they are too hot to touch. My motors are a little warm but seem fine. I haven't had a problem yet but concerned. Here are the specs: http://montorc.com/Tiger-Motor-U5-Power-Series-400Kv-Motor.aspx My AUW will be around 22lbs here very soon so my question is, should I be upgrading my esc's? And which ones are good to look at? Thanks!
If your getting temps over 160f, I would be concerned with the 35amp esc's you are using. 220f is a typical power down temperature you never want to hit. I have a X8 with U7's, 17" props on top and 18" props on the bottom and get temps of around 145f with a 26lb copter weight running Maytech 65A OPTOs at 75f ambient temperature. I think that temp is a little high for my taste, especially when flying at 100f ambient, my esc's will be hitting 175f+. What I have done is added heat sinks to my esc's and 25x25x7 mm hobby wing fans. I have now been seeing temps of around 115f at 80f ambient temperature.
AJ if you can't touch them they are underpowered. An IR temp gauge would help. What ESC's are you using?
Motor overheating is rarely an issue in my experience. I’ve personally never had a motor fail in that way. It’s probably partly due to the cooling effect of the props and the motor keeping air flowing over them. But the ESCs are typically not in the airflow of a copter, and especially when our AP platforms spend a a good deal of time hovering in one place, the ESCs can get very toasty if they’re at their redline, or anywhere near it. It’s a small investment relative to the cost of your kid to upgrade to more powerful ESCs. Correct me if I’m wrong, but I don’t think you can have too much ESC capacity. You might want to look at KDE’s new ESCs. I have a lot of faith in their stuff, and I hear a good buzz about them.
I feel the same way Steve, hence my questions... The dealer I bought my U5's off of said they were plenty but I am having my doubts. The ESCs are T-Motor 35A. I fitted them with full heat sinks but need to see exactly what temp I am reaching. My motors are always cool and only very slightly warm sometimes. Also ever since your build I have been drooling the KDE stuff.. if indeed you can't have too much headroom then I should just bite the bullet and upgrade. Thanks for all the info guys. And on another note, SYNAPSE!!! I have money burning a hole in my pocket guys!
I think that oversizing the esc is important, but part of the issue is the voltage range of the esc. The Maytech's Im using are 3-6 cell and I am running them at 6 cell and they run a bit hot due to running on the upper limit of the esc cell limit.. If I could use a esc with a high cell count rating like the t-motors 70A or 80A 5-12S esc, they supposedly run cooler due to the higher voltage range.
One thing you’ll find if/when you move from a 4S to a 6S system is that the higher voltage can result in lower operating temps and less stress on the components, assuming they’re all truly 6S (22V) compatible. That’s because in order to get to a particular wattage figure (the actual thing that spins your props), a 6S system pushes 1/3 less current to get there. When I was flying 4S, I was right on the edge of all the components’ heat limits. Now that I’m running MK’s BL 3.0 at 6S, often my BL temperatures are only 10°C or so above the ambient temps.
Guys Im running an Octo AUW 24 Lbs U5 motors 16x TG CF Props Maytech 65Opto Esc with heat sinks Power hungry distribution 2 6S QC 10000 lipos 10 minutes flight hover & side to side test flight 39% left after 10m the Esc are slight warm but the motors are hot could it be a timing issue ?