Lproee

Hello again,
Well I replaced all the servo extensions in the sbach to heavy duty servo extensions.
But still the problem returns. As I move fast all the servos the reciever voltage that shows on my transmitters drops all the time from 6.6V to 4.5v and even less!
Is it normal? Im pretty concerned about the voltage drops and dont want my reciever to stop working mid air��
What can I do?
Oh and it was connected to 6.6 single 2300mah 30c LiFe battery.
Thanks!!!

speedracerntrixie

My Feedback: (29)

Hard to know without looking at it. Pictures may help. Where do you have the switch pluged into the RX? As stated previously, I too use an Aurora 9. I have not had this issue even while running a 850 mah LiFe pack on a pylon airplane with electric retracts. My guess is that it can be anywhere from the battery to the RX. You did replace the jumper into the SPC right?

Lproee

Yes, I installed the jumper back into the SPC port.
the battery is connected to its ch9\battery port.
Another interesting thing. Using dual battery setup (dual 1700mah 6,6V LiFe 20C)
the voltage drops from 6,6 to 5,7V both in high rates and low rates.
Could it be the wire coming out of the battery? It looks thinner than the HD extensions.

ahicks

My Feedback: (2)

"4.5v and less" is not normal, and I wouldn't fly it like that until you figure it out. That's exactly how I lost my Funtana. It would be OK on the first flight of the day, but somewhere around the second or 3rd flight, that's exactly what it would be doing, accompanied by beeps coming from the transmitter warning there was an issue (A9 here too).

You say you have a dual battery setup, and it's able to maintain 5.7v. That leaves me with 2 questions. Why aren't you trying that, and how are you hooking up the power coming from the second battery? Also, I would be suspect of power leads coming from your battery that is smaller than the wire used in a HD "Y" or extension.

Have you tried setting it up as I suggested earlier (using a "Y" in the rudder lead)? It would only take you a minute. I can tell you with absolute assurance it took me from problems like you're describing to flying with confidence for the last several seasons.

speedracerntrixie

My Feedback: (29)

Something is not right. I too suspect that the voltage line into the RX is not up to the task. At this point there is a single battery and switch in use the way I read the OP last post. On a model this large I would be going with dual inputs. I think either going with a single battery with dual 22 gauge outputs ( or dual batteries ) to two HD switches with 22 gauge wires, plugging one of them into ch9 the other into any other available slot and leaving the SPC jumper intact should fix the problem. If not then I would check for binding control surfaces/linkages. It may be a bad RX as well. The only time I used an Optima RX in a giant scale without a power box, I ran a single 7.4V 3000 mah Lipo. It went to an MPI regulator set to 6V with a single 18 gauge input and two 22 gauge outputs. While moving all controls quickly the most drop I could get was down to 5.8V using 4 Savox 160 oz digital servos and one analog throttle servo.

Lproee

Using Y harness with the rudder servo and the second battery results drop from 6.6V to 5.4V. I guess its a little better.
Anyway, Im going to try this little part: http://www.amain.com/Spektrum-Voltage-Protector/p6570
It may be good protection from those voltage drops.

BarracudaHockey

My Feedback: (11)

Not really, unfortunately

jim billings

While discussing the size of the wire making connections to servos, don't forget the connectors at the end of the wire. The pins in the connector body measure about .0225 inches in diameter. A pin that size has the current carrying capacity of 23 gauge copper wire. Using wire any larger (like 18 gauge) provides no safety factor because the connector will fail long before the wire.

flycatch

My Feedback: (26)

Don't buy any extensions made in China. Don't believe me than do as you please.

Len Todd

Did you try totally bypassing the switches (i.e. feeding the battery directly into the Rxer?) Most of the switches out there and their small gauge wire and connectors are not good for Giant Scale Plane loads. Got to really look at the switches specs and calculate the worst case loads, etc. (e.g. Nine servos times up to 5 amps = 45 amps.) Now think about it. Some folks are really trying to get 45 amps thru one or two JR connectors all the way out to a giant's servos?

Where exactly are you measuring the voltage, when you see the drop?

Did you measure the voltage out at the servos to see what the real voltage is at the servo (i.e. end of the line.)? Less than 5 volts at the Rxer, to me, is a problem.

I ran into these types of voltage drops before trying to use the Rxer Bus for the power distribution. After a lot of froggin' around I went to powerboxes. They also add the failsafe switching and power source redundancy. Although, ... I am trying a smart-fly power expander in the next plane. But it has the failsafe switch and power source redundancy also.

Also, I like HV servos. They are quicker to respond and seem to hold up really well to 2S LiPo voltage. Don't need a regulator either. But if you do regulate them down to 6V, them seem to last forever.

As to extension wire gauge, I use JR HD (22 Gauge) on everything except the PA planes I have. The PA Planes' are small & light and use the thinnest gauge servo wires I have seen and they have you cut them to length without the extra connectors. My AW Extra has a 108" in wingspan. I don't see much drop out at the servo at all.

Another route is to hardwire all the servos directly to the power source and just the signal lines come from the Rxer. But again, the switch, if used, on that harness becomes a limiting factor.

I use 2s LiPos and they come out for charging. So all my planes w/o power distribution boxes have EC3s for switches. Have not seen an EC3 fail or cause a voltage drop yet.

hobbychina2010

1Y harness for ailerons2 for (split) elevatorThrottleRudder

Lproee

Hello again.
I tried many setups and the best results shows with this one:
Y harness connecting between the rudder servo and 2300 mah LiFe battery. The male connects to the rudder channel in the RX.
Novak Glitch Buster to 8th channel, and 1700 mah LiFe to the original battery port.
Using this setup on high rate the voltage drop from 6.7V to 6.2V.

Is it safe ?
Thanks!!

speedracerntrixie

My Feedback: (29)

I would not fly with that voltage drop off. I would try a different RX or send that one in to Hitec for a check up. I have an airplane with 8 400 oz plus digital servos and with moving the sticks to full travel I only see a .2V drop. Something is still not right.

Lproee

Could it be the battery?

Lproee

Could it be the battery?

Muttdog

Running 2 batteries with different Mah ratings like you are doing can have adverse effects. I would recommend a smart fly bat share device when using batteries with different mah ratings. This way it will deplete the batteries evenly and it's cheap insurance against one of the batteries shorting out. Spektrum powersafe Rx's have this feature built in

Lproee

I tried also using dual 1700mah LiFe batteries but nothing changed...
Also, in some cases the Rudder servo stucks. Nothing wrong with the pull pull system, and this problem also occured in one of the elevator servos.
update: The system has been tested with another rx. Same results.

Thanks again.

Muttdog

How are you getting those numbers? After I fly I check my min/max report from my telemetry module (spektrum) for that flight and I routinely see voltages in the 4.5V-5.5 min range and lower. This alarmed me in the beginning but in my case I think it is just the design of the tm1000 telemetry module. I believe that there is no delay or hold when it reads the voltage and just records the absolute min and max voltages. The problem with that is the voltage can spike to extremes but that is most likely only for a very small period of time (milliseconds) and otherwise would be almost unnoticeable. I would prefer that the tm1000 would require a voltage to hold for some specified amount of time before reporting it to avoid reporting spikes. I have also noticed that if the engine dips below 900 RPM my telemetry will report over 100K RPM as a max for the flight so the tm1000 is not exactly foolproof (I'm proof of that). I have been flying my 35% Yak with 2 LifeSource 2100 Mah packs for a year now with these same results and zero issues.

Lproee

I am getting this numbers from the Hitec telemtry. The optime 9 rx sends the battery voltage back to the a9, and like you said, it shows the min/max voltage. But every time Im playing with the sticks the voltage that shows on the A9 drops down and goes back up when I let go of the sticks.
So you say it may be OK?

BarracudaHockey

My Feedback: (11)

You can get rid of the useless "glitch buster"

Lproee

Already done.

speedracerntrixie

My Feedback: (29)

I would call Hitec and pose the question to them Be sure to let them know that you had a battery hooked up to the SPC and battery port at the same time. Was this done with both receivers you have tried?

Lproee

I tried both with the spc hooked up abd also without it.

OldRookie

My Feedback: (13)

How much total amperage are the switches you people use capable of?
I was checking some quality switches and found the following.

Fromeco Badger switch...13 amps...http://www.fromeco.org/Products/04FRCBADSW-420s/

Fromeco Wolverine dual redundant...15 amps each switch...http://www.fromeco.org/Products/04FRCWO-430s/

Electro Dynamics Ultra Switch...10 amps...http://www.electrodynam.com/rc/usw/index.shtml

If you have several servos pulling 3-5 amps as some of you have suggested, wouldn't the amperage demand exceed the switch capability?

Greg

OldRookie

My Feedback: (13)

My set up for a 50cc plane is as follows:

Dual A123 6.6v 2500 mAH batteries...http://www.electrodynam.com/store/product297.html
Wolverine dual redundant switch....http://www.fromeco.org/Products/04FRCWO-430s/
Tech-Aero IBEC...http://www.tech-aero.net/ultra-ibec
Servo City Power Board...http://www.servocity.com/html/servo_...l#.VF4hPGfzj6U

This set up allows me to use 18 gauge wire from the battery to the switch, and then to the power boards buss bar, and has proven to be extremely reliable.

Greg