Gavin2407

Good day Everyone

We had a great flying weekend with almost perfect weather, little gusty at times though. Well yesterday after the 4'th flight, I had to rebind my heli after making some setup changes. When I removed the canopy, I felt than the Rx battery (Sanyo 4.8v 4600Mah Sub C Nimh) was quite hot. Felt over the rest and found the rudder servo (JR 8900G) almost untouchable it was so hot, other servo's (Align 610's) also warm but not hot. JR 721 Rx also quite warm. The Titan 50 SE has a FRP canopy that fits more snuggly over the nose than the old plastic "bleach bottle" canopies, could it be a ventilation issue? the rudder servo sit on the tail boom out in the open, would hate to think what it would've felt like if it was inside the canopy. Please if anyone has ideas on what I could look at or if this is "normal", let me know. I have never felt the components after a flight before, just normally refuel, recharge and test functions before the next flight.

Regards,
Gavin

BarracudaHockey

My Feedback: (11)

Rudder servos get too hot from too much gain, too much voltage, or binding in the control system.

I'm curious as to what would make the battery heat up like that unless you're really pulling some amps from somewhere.

I'd really suggest an inline amp meter and see what your system is pulling when you're moving all the servos.

Gavin2407

Hi Andy

I have an Hangar 9 inline amp meter that I use for my setups. With links off, current draw is between 2 and 2.5 amps. With links on, current draw is between 2.5 and 3 amps. This current draw is while really banging the sticks around, which I don't do while flying. whether this is a clear representation of my system, I don't know as heli is stationary on the ground with engine not running. factors like wind, rotor resistance, vibration, etc... are not having any effect on my test but will have an effect while flying. From your post about the rudder servo, I can just say I know there is no binding and that the gain is not to high because tail doesn't "wag" on me or let go/ over correct while flying. I agree that it could be high voltage but I'm running a 4.8v pack and it should only be high voltage for this servo if straight off a charge. I do quick charge at the field but will leave the heli to "rest" for awhile, maybe 15 - 20 minutes before flying it. If the rudder servo is drawing major current during a flight, thus getting hot. would it not then cause the battery to get hot also from the current demand? Is there something that I could get to measure maximum in-flight current draw and voltage?

Regards,
Gavin

BarracudaHockey

My Feedback: (11)

2 amps just sitting??

Disconnect servos one at a time, my guess is one of them is causing excessive draw.

helifan06

Silly question, but did you check the voltage rating on your rudder servo? Some futaba rudder servos works at lower voltage, so you need a step down voltage regulator, those given on the TREX600. I use Align servos, so I don't need this regulator.

my 2 cents,

Gavin2407

Andy

Yes, 2.5 amp is max current draw while banging the sticks around while on the bench. Will check with disconnecting 1 servo at a time and post results.

Helifan06

I'm running Align 610's on cyclic, collective and throttle. Running the JR 8900G with the JR G770T gyro. I know 8900G can only work on 4.8v, which is why I'm running a 4.8V Rx pack. yes voltage could be to high just off charge but my pack drops voltage quickly but settles on about 5.4v

Thanks guy's
Gavin

BarracudaHockey

My Feedback: (11)

Oh ok.....i thought you meant while it was sitting there. Thats about right then.