JR G770T Gyro and DS 8900G SetUp

[malc1]

I`m trying to install a JR 770T and 8900G combo in my TRex 600 N.
Has any one else any issues with the servo being very very noisy and twitchy as soon as either rate mode or heading hold values are switched in off the transmitter?
The tail linkage does not need to be connected so it is not a binding or smoothness issue.
I`m using a JR PCM synth tx and 3810 TX.
Just wondering if there is something I`m missing somewhere :dontknow

[terrebse]

IT is supposed to be "normal". It is almost like the gain is too high. mine does exactly the same. It does not affect flight performance. :shock: :twisted:

[agiaffa]

I have a DS8900G fitted to the G770T and my G8900 is very noisy and twitchy as well.

[malc1]

Is it the Gyro or the servo causing it?
It does warn you in the instructions for the 770 about using the 49% to 51% range on the gain menu as its unstable. :dontknow
I`m sure all will be ok when in flight but I still don`t like it :!:

Anyone else getting the same thing :?:

[DJC]

So how is it going with this gryo?????????????
I was waiting for this.
Am I wasting my time??????????????

[terrebse]

The g770 gyro ang 8900g servo is one awsome combo. I have now removed my futaba 401 and replaced it with g770 combo aswell.
Now my Trex nitro pro and kasma raptor have this combo on. Both gyro's seem to noisy on the ground but when they leave the deck the gyro is awsome........

[jet78]

greetings all,

I'm having the same problem with the gyro twitching on the ground... I have brought my gyro gain down
to like 53% on my futaba 9chp radio.... I'm using a webra 55 with a tuned pipe combo on a Trex 600 n sport

even at hovering, the tail seems to wag alot...( not sure if my head speed is too low... cos I'm still running in
the engine)

I have yet to determind the problem as this is the FIRST heli being build by me...

[EatMorePizza]

Wow i thought i was going crazy. My servo also make sthat crazy noise. It lurks me so much It reminds me of binding. Does any of your helis durring hover see that the tail swings by its self with no rudder input.

[jedijingle]

what is the performace like with this combo. Is it better than the gy 611.

[JC]

Did the specs (http://www.jrradios.com/Products/TechnicalSpecs.aspx?ProdID=JRPG7703DC) of this tail servo change? If you would have asked me before yesterday, I would have bet $ that I read on JRs website for this servo/gyro combo that the tail servo DS 8900G was capable of 6 volts.

I looked at the site yesterday as I was sending the link to a friend and it clearly shows 4.8 volts only. I'm fairly certain I would have noticed the only part as it kinda sticks out there. The spec states "Speed: .05 sec/60 deg @ 4.8V ", and thought it also showed .02 sec/60 deg @ 6.0V before. ??
I also now see the line that states "(Note: Most tail servos are limited to 4.8V)".

Maybe I just confused it with the 4.8 or 6 volt specs for the 8717 servos I also got. :thinking

I ran it on 6 volts for 5 flights before I saw this as I was sure it was listed as 6 volts. I hope now that I didn't damage it.
I put the 5.1v step down regulator on it and it sure has quieted down. It's now only slightly noisier than the intermittant chatter I get with the 8717 cyclic servos. Seems to be still working fine.

Am I losing my mind or did anyone else know (or think) that this was a 6 volt servo?

[Soren]

From the manual:
The rudder servo may shake slightly while
sitting on the ground. This is the Gyro's
characteristic feature, and not a fault.

[phantom1500]

JC, The JR site did state that the gyro was 6v and 4.8v rated, I use a 7.4 lipo with a 4.8 reg which outputs 5.1v. Mine is also noisy but some tinkering with the heli not running but power turned on to the rx, you can move the heli on its axis slightly and the noise will stop....think from all I've read that its normal and just the gyro doing its thing.

[gbeeusae]

Hello, I am setting up the same combo on a Titan 50. I planned to step down the voltage to the servo initially but where the gyro is located I would have to put the step down there and I don't really want to have those extra connections out in the open.

I then thought I would step down both the gyro and the servo at the RX but there is that white connector and wire for the gain. Would it matter if that was at 6 volts? I am using a 7.4 lipo with a 6Volt 6 amp regulator.

I looked at the JR site and they have 4.8 volts only listed for the 8900G.

Any suggestions would be great. Thanks.

[idigrc2]

I have mine pluged into a spektrum regulator, Keeps the gyro and tail servo at 5v. If you want to use just a step down then plug the step down in between the gyro and the servo. The gyro will still be at 6v but the servo will be at 5v