JR G770 Gyro Setup Videos + some new 101's

[Tomek]

I'm a total n00b and can't at all figure out any of this stuff for the life of me. I'm trying to mess around w/ my trex 450 that i bought on ebay which has this servo. whenever I turn the heli on and move the rudder, i get max deflection of the tail blade very quickly...as in i deflect the stick maybe 1/3 of its full range and the tail blade is already maxed out. I have to dumb down my end points way down to get full resolution (way down to around 20-30 from 150%). what am I doing wrong???

[hotdogbun]

Hi Fin, I need some advice.
I am using JR G770T with Futaba 9257 on my Protos.
The servo ball link set at 11mm from centre of horn, I am not getting full throw on the tail slider even with Gyro's servo throw at maximum. Reason for setting to 11mm is because if I use another further hole, it seems to be quite far out. With all this, I am causing the link rod to rub against the rod guide.
Strang thing is, my gyro is holding rock solid even at fast tail slides and reverse flights.

My question is, can i use a further hole (3rd from centre) on the servo horn? With this hole I do not need to max our my Gyro's servo throw and the rod will not rub the guide.

Many thanks.

[hotdogbun]

Sorry forgot to add, I am on 2nd hole from centre which is about 11mm. Using the 3rd hole from centre the distance between will be about 14mm.

[Pinecone]

Originally Posted by Tomek

I'm a total n00b and can't at all figure out any of this stuff for the life of me. I'm trying to mess around w/ my trex 450 that i bought on ebay which has this servo. whenever I turn the heli on and move the rudder, i get max deflection of the tail blade very quickly...as in i deflect the stick maybe 1/3 of its full range and the tail blade is already maxed out. I have to dumb down my end points way down to get full resolution (way down to around 20-30 from 150%). what am I doing wrong???

You aren't doing anything wrong, that is how a heading hold gyro works.

The rudder input is telling the gyro to make the heli piro at a given rate. But since it is sitting on the bench, it doesn't move, so the gyro puts in more tail pitch to try and get the piro rate. But hard to piro with no power and sitting on the bench.

Do NOT lower the end points. Set them at 150% to start.

Don't worry, this question comes up about every other day.

[Tomek]

Well that's reassuring Now who can tell me how to set one of these 770's up on a JR XP6102 transmitter?!

[Finless]

Dang Piney... How many times have we answered the stick to servo movement question?

I gotta cover that in this vid and I WILL! In fact I really need to do a Gyro 101 video over to cover this as it comes up a million times!

No offense to you all guys that ask but this is a COMMON question that gets asked over and over again... So I gotta re-shoot the gyro 101 and this time maybe cover MANY gyros!

Bob

[darrenwootton]

I have solved the bounce back problem on the right piro, I used aligns metal giro plate with two lots of self adhesive pads and a Velcro strap, the tail is real solid now and the stops on the tails are crisp fast with no bounce back , it now feels like a different gyro , now its awesome gyro when you know how it works.

My latest setting are

• rudder left end point is 100 and the right is 90
• My gear is -24 and +24
• Dual rates are now 84%
• Expo is 55%
• The gyro pot is at 100%
• All controls are set mechanically to 90 deg vary important needs to be spot on
• Set on the first hole on the servo wheel
• Set up in HH MODE NOT RATE MODE get the pitch slider in the centre which will give you about 8 deg of pitch that’s it the gyro will do the rest don’t make it more complicated it not need be, I fly in HH MODE all the time the same as finless bob does so no need to play with rate mode.

I have spent the last three months playing around with this gyro it has been a real pain but when you understand how it work its ace and worth the time and effort to get it right, The piros in both directions hold better and more consistent then the 611 with no tail whipping over the top side of the piro.

Upgrade your tail to metal tail grips and you will be able to turn the gyro gain up even more

I think with some small adjustments this gyro can be even better but you must remember if you turn the gyro gain down the piro will speed up and visa versa .
Find a fine balance with both gyro gain and rudder duel rates and keep the settings together so if you move the gain up or down remember to adjust the rudder d/r the same amount


I hope this information will help other JR770T Gyro user have fun and happy flying

[Finless]

Personally, I would NOT mount the gyro that far forward on a Trex600 (Electric or Nitro) as I have seen MANY times that noise from the drive shaft bearing causing gyro glitches or drift! I think with all that tape and the metal plate you have masked this issue when probably all along you should have just moved the gyro back as far as possible.

You have the gyro sitting RIGHT on top of a bearing and it can cause NOISE to the gyro sensor! It maybe working great now but as the bearing gets wear, thus more noise so don't be suprised if you start seeing random "tail hits" or glitches later!

Bob

[Empot]

I have mine on the gyro plate on top of the servos for the 600N so far so good is that ok?

[TheBum]

Originally Posted by Empot

I have mine on the gyro plate on top of the servos for the 600N so far so good is that ok?

The noise is going to drop off exponentially as you get farther away from the bearing, so you should be fine. I've been flying with my G770 in the same location as your gyro for quite a while with no issues.

[Finless]

Yes you are OK using the gyro plate on the 600N above the servos but you do need the metal plate which helps block the noise. That is where mine is with the plate and no issues thus far.

Bob

[DarkHeli]

My gyro is mounted on the front plate but I had to move it maybe 5-8mm BACK. I drilled new holes in the carbon fiber and its working fine. I had to do this because my canopy was rubbing against the gyro corners and that was transferring vibrations.

[TheBum]

The G770 has a metal case, so I would think that the plate is less critical with it.

[Pinecone]

Originally Posted by Finless

Dang Piney... How many times have we answered the stick to servo movement question?

I gotta cover that in this vid and I WILL! In fact I really need to do a Gyro 101 video over to cover this as it comes up a million times!

No offense to you all guys that ask but this is a COMMON question that gets asked over and over again... So I gotta re-shoot the gyro 101 and this time maybe cover MANY gyros!

Bob

Several times a day on average, for at least 2 years for me.

Yeah a Gyro 101 vid would be a good idea.

[zaboaa]

Flew my first flight with my new/just built CF TREX 500 today with the 7703D. Tail held rock solid. My gain is really low (see below) and I definitely see a lot of back lash, have to read up and see how to get rid of that. But over all initial set-up by the manual is a good start. Here are my DX-7 settings as relates to the 770:

No sub trim
Rudder end points: L 150%
R 150%
Gain settings (using the gear channel and end points):
+ 51% (does this seem really low, starts to wag a little any higher)?
- 30 (rate mode, I get a slight drift to the left in rate mode)
D/R & Expo:
RUDD

EXP +50
D/R 75% (gives a nice controllable pirouette, but rockets a full stick)

I am brand new to this gyro (450 has a 401) so any thing that sticks out/pointers appreciated.

Thanks..

[Finless]

If your using gear end points instead of the gyro menu then +51 is high! Remember on JR it is not 1 to 1. e.g. 30 end point is not 30 gain. My futaba 611 which has a display on it shows a gain of 28 when my end point is 40. So 51 is a lot higher! I think that is probably too high for the 770.

The math to figure out true gain using end points (not gyro menu) is
End point / 1.44 = true gain
So 51 / 1.44 = 35.4 gain. I don't run my 401 or 611's that high. more around 32 at the highest.

Bob

[zaboaa]

Alright then I was confused (referring back to the manual I see what you're saying). I just recently went to the gear channel on my 450 so this is a little new. That probably explains the rebound/backlash I had. So just to be clear if I am below 0 than I am in rate mode ? Also I know in previous posts I think you say not to take away the drift in rate, just center the slider mechanically and move on. That is the way I did mine (centered mechanically), seems to work great. Are you still convinced that is the way to go? Thanks for taking the time to help me....

BTW the numbers/math are a huge help....

Mark from Texas...

Originally Posted by Finless

If your using gear end points instead of the gyro menu then +51 is high! Remember on JR it is not 1 to 1. e.g. 30 end point is not 30 gain. My futaba 611 which has a display on it shows a gain of 28 when my end point is 40. So 51 is a lot higher! I think that is probably too high for the 770.

The math to figure out true gain using end points (not gyro menu) is
End point / 1.44 = true gain
So 51 / 1.44 = 35.4 gain. I don't run my 401 or 611's that high. more around 32 at the highest.

Bob

[Finless]

The JR manual is NOT telling you to set up in rate mode and telling you to center the the control. So based on that seems you do not have to setup in rate mode. The Curtis Gyro is like this as well and in fact doesn't even have a rate mode!

Well using end points you cant go lower than 0 on either end point. So one end point is rate mode gain and the other is HH mode gain. Bringing both to 0 means 0 gain in either mode.

Bob

[satl]

My Zeal tape arrived in the mail. It is some neat jelly stuff.

First, I put a whole square on, and it helped, but I still had a slight drift.

Then, I cut two 8.5 mm strips, (the instructions suggested using 5 - 10 mm strips), and that did it.

I've also got it secured with a velcro strap.

It's nice to finally have the drift gone.

[Empot]

Thanks guys for confirming that. I had to remove the carbon tail blades and put in K&B and up the gain 2 clicks. I get severe wagging with the carbons when I fly FFF and make a right turn none on left turn. If I turn down the gain a little it drifts a little when I do hard 3d. Now its on a happy medium it holds well on 3d and no wagging on tunrs with K&B blades. My endpoints are 138 left and 150 right with 53% DR an 63% gain on gyro menu on DX7. By the way I fly a 600N