csm 720 9256 problem at 5.3v regulated

[harmdive]

Hi all

Just had a pretty scary problem with my Titan 50. Here's the story, maybe you can help. I had a maiden flight yesterday having just changed over to fromeco li-ion power. Using reliaswitch and 2600 battery. Went careful for the first couple of flights and then pushed it pretty hard - elevator tic tocs and general 3D. Started doing tail down tic -tocs and then suddenly the tail conpletely lets go - no control until I stop the move and then everything is ok. This happened each flight I did this move.

At first I thought the battery was faulty - checked (no problem there). Charged up and then went again. Sport flying first and then hard 3D, tic toc again and same problem. I'm running csm720 gyro with 9256. I've set the voltage to everything at approx 5.3v. Wondering whether this is too much for the servo to handle under excessive load during this manoeuvre or the battery is not supplying enough current to run everything. I am running jr 8715 on cyclics -
pitch - 8711
throttle 810g

Anybody had the same problem? Now off to fly but I'll be back later hopefully with the heli in one piece!

[Jafa]

You may have to data log the battery voltage - it may be dipping with those servos

Do you have the 2 cell 2600 pack or the 4 cell pack?
The 2 cell pack has high internal impedance, 28mohm
That's why the large IMAC planes don't use it, they use the 4 cell pack
cos it halves the impedance and delivers better sustained current/voltage

[harmdive]

I have the two cell 2600 pack. I have a 5200 4cell pack ready to go and I'm hoping this will solve the problem as it will supply enough current for servos under load. Don't know what the discharge rate is for fromeco batteries - i hope it's enough or I'm back to using nimh.

[harmdive]

I've just looked on realraptors website and found that the discharge rate of the 2600 pack is 4amps. I'm wondering whether my titan draws more than 4 amps during extreme moves and so the battery can't supply enough. 5200 pack discharges at 8 amps - this looks like a better figure with the servos I'm using.