coolbean

I've been flying for some time with a 9.6V 650mAh NiMh pack with my Phoenix 25 ESC set to 5V cutoff on a HIMAX 4166 motor on 4 to 1 gearing with a 10X6 prop. Have had no problems at all.

I switched to a Thunder Power 3 cell 1200mAh LiPo pack with the Phoenix 25 ESC set to 9V cutoff on the Himax 4166 on 6 to 1 gearing with a 12X8 prop (sounds big to me, but the motor specs recommended it with a 3 cell pack)

I can run the throttle up about 2/3 then (i assume) the voltage cutoff kicks in and shuts it down. I dropped the cutoff back to 5V and it runs fine, but I don't want to risk ruining my battery. The esc does have a LiPo auto detect cutoff, but if that is working properly it should put the cutoff at 9 volts and would work just the same as if I manually set it at 9V, Right? Any suggestions?

Also I'm having problems getting my esc into programming mode. On my computer radio it simply won't acknowledge that I am at full throttle when I plug the battery in. I tried changing the travel all the way up to 120% and the trim tab all the way up and it still doesn't work. I had to go back to my old basic 4ch radio and it only works if the trim tab is all the way up and even then only about 1/4 of the time. Any ideas there?

exeter_acres

My Feedback: (2)

try a smaller prop...

as for programming, I use the USB cable, so can't help you there...

coolbean

Well I found the spec sheet and it turns out I am overpropping it. 12X8 is suggested for 2 cell lipo but for some reason it reccomends an 11X7 for a 3 cell. Seems odd to me, but OK. Could i go for a 12X5 or 12X6? The plane I am flying is pretty heavy and I need the largest prop I can get.

bhole74

The CC controllers have a 3-cell cutoff of 9v, which in my opinion, is too high. If you get the Castle-link, you can adjust the voltage cut-off down a bit and it should eliminate the problem. I had this problem with a CC 10 until I got the link, adjusted cut-off at 8.4v, same as a Bl-8. My Hacker has a 7.8v cut-off for 3-cells.

Mayday!Mayday!

Cool, the reason the 11x7 was recommended is as you go up in voltage(the 3s lipo) you need to prop down. You will be turning at higher rpms and with a large prop you will be pulling too many amps through the esc. So using a smaller prop usally takes care of the amps and you still have the thrust and rpms you need. I suggest getting a watts up or astro meter and use moto calac to get an idea of what you need/like as a prop, cell, esc combo. BG

coolbean

Well I tried a 12X6, that kicked in the cutoff at about 3/4 throttle. Tried the only other e-flight prop I had a 10X6 and it ran that just fine. Guess I need to pick up annother prop or two to test with.