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JR g500t Gyro Problem

tk62flying

Heliman

Helena,Alabama

Heli : Ergo 30 SS ccpm
Radio : XP 662 ....

Switched gyro 's monday flew yesterday afternoon Heli spins to right have tried correcting problem with trim function on radio ... spin gets worse ....at 8 + or - ....gryo gain was +50 reduce to + 46 no ghange what am i doing wrong ? need help thanks ...

01-30-2004 Over year old.
Darren Bradley

Veteran

UK

Sounds like you need to REVERSE the gyro sensing on the gyro. I think on the 500T there is a little switch on the side.

Go back to the manual to check you left and right throws and gyro sense .. ie.

Move your stick to give a right tail input , and notice the direction of the tail blades and servo arm . Then pick up the heli and move the nose to the left and see if you get the same movement ..

Hope this helps

Daz

01-30-2004 Over year old.
Fifer

Senior Heliman

Fife Scotland

yep had the same prob last weekend with my caliber just fitted the G460T flicked the reverse switch and it held great.

01-30-2004 Over year old.
tk62flying

Heliman

Helena,Alabama

I'll cheak again , but think it was already in rev. hey Fifer I had the 460t and really had bad results (crashed) sent to horizen they cheaked it and replaced with the 500 was really impressed with horizens warrenty on that gyro....

01-30-2004 Over year old.
shootist

Senior Heliman

New York State, East Coast US

I found that my 500T would move slowly to full lock (on the bench) if I had even a few clicks of trim or subtrim.
Try turning on the radio in HH, then turgning it off before you lift off. Carefully lift off, and see if your mechanical tail set up is okay. If its not, the tail will start to rotate. Adjust the linkage until non-HH is solid in a hover.

01-30-2004 Over year old.
Fifer

Senior Heliman

Fife Scotland

Thanks tk62flying I just needed that info now I will wonder every time I fly if it is going to come down with a crunch.

all jokeing aside It has been a good gyro to me I had it in my nexus with no probs.

hope you get yours sorted out.

01-30-2004 Over year old.
tk62flying

Heliman

Helena,Alabama

Fifer, no jinks intended , the r/c gods will always fly with you...

shootist , yep ; thats exactly as you describe , will try it out tomorrow

Thanks for the Info guys

01-31-2004 Over year old.
Joe P

Heliman

Morristown, NJ

If the Heli spins fast around when you get light on the skids, the gyro is reversed. If you do TR left and the nose goes right(from behind the heli) then the radio is reversed. Optimal gyro gain should be above 70-95ish%

01-31-2004 Over year old.
jbiter

Key Veteran

Sebring, FL

Was your old gyro a simple rate gyro?

If so, the fix might be to turn off your tail compensation (JR) or revo mix (Futaba).

Just a thought

Jeff

01-31-2004 Over year old.
tadawson

Elite Veteran

Lewisville, TX

Shootist -
Drifting to lock when a trim input is present on a HH gyro is normal - for ANY HH gyro! Since you are effectively commanding a piro rate, the gyro will keep increasing output until it senses that rate, which on the ground will be never, and it will hit limit. Try putting trim into a Futaba ?01 and you will see the exact same behaviour - it's just part of HH!

- Tim

01-31-2004 Over year old.
135boom

Senior Heliman

Deerfield, Illinois

G500T

The problem you are having initially sounded like the reverse switch is wrong. After you fix that issue, take out ALL trim, subtrim, and disable Rev0(tail to throttle mixing). JR tried mixing rate and heading hold instructions together and used an "*" or dot indicator to state that those instructions marked with the indicator are for RATE SET GYRO's ONLY!
Because you set subtrim, your basically telling the tail to move. Bad move. Now if you did that instruction my guess is that you also set up the Rev0. again take that out. That will really make your tail spin.

To simplify things for all you G500T users here are some setup instructions for those that will connect the remote gain wire:
(these instrcutions assume the gyro is properly mounted)

1) Set ALL rudder trims to zero (0). This includes the subtrim.
2) Disable your Rev0 (rudder input to throttle change).
3) Set the rudder travel to 150%(or whatever max travel you have)
4) Set the channel you will be using for remote gain to +75%. (I used the gear channel at +75 for heading lock and -100% for rate mode....the negative defines rate mode)
4) Connect the gyro to the receiver (again, I connect my remote gain to the gear channel, but you can use whatever channel is open)
5) Disconnect the tail ball link. (This will prevent overtravel damaging anything.
6) Power up the system and wait about 3-5 seconds.
7) Move your rudder stick left and right and check if you will have any binding by looking at the difference between the ball link position and the max travel of your rudder(tail rotor) bellcrank for that direction. If there is a difference and it is roughly equal adjust the LIMIT potentiometer on the gyro to limit the travel, reconnect your pushrod and go to the next step. If the difference is NOT equal, adjust your linkage and bellcrank position until it is, connect the ball link, and then go to the next step.
8) Check the gyro response to yaw movements. I do this by moving the stick left and noting the rudder servo bellcrank direction. Center the stick. While watching the rudder servo bellcrank push the tail such that the helicopter nose goes right. The gyro response should drive the servo bellcrank the same direction as when you put in left rudder stick.
If you need to reverse the gyro response direction, you MUST cycle the power to the gyro.
9) With everything working properly fire up the machine and get it into a hover with the gyro in HEADING LOCK MODE.
10) If your have tail drift or it doesn't seemed locked in, first check you mode switch. If switching that doesn't fix the problem land and add gain.
11) With hover set-up fly around in fast forward flight. Here you might get tail wag. If you do, land and lower your gain. Some people use Aux 3 and can have multiple gains for the tail, but I personnaly sacrifice hover tail lock for forward flight performance.

If you need to reduce gain below 75%, take you machine back to the bench and move your balllink on the servo side in one hole. JR says the G500T performance drops off when below 75% gain.

To adjust your tail in Rate Mode, set the machine to rate mode and perform adjustments on the tail pushrod. Note that when you do this that you may need to recheck youu travel limits to prevent binding or overtravel in one direction or the other.

That's the nuts and bolts of it. JR didn't do the best on the instructions, but it's basically the same as a Futaba GY401.

Good Luck.

03-14-2004 Over year old.
reefguy

Senior Heliman

palmdale california

gyro

anyone using a futaba 9chp with a jr gyro like 500t or 5000t, the question is in the advance menu, is gyro sensing act or inact, is the mode 'gy' or 'std', also, according to the jr gyro manual, and to use end points and sub trims to control gain, is this correct for you guys using this setup? thanks

03-30-2004 Over year old.
135boom

Senior Heliman

Deerfield, Illinois

GT500T With Futaba

After some work with Horizon/JR I learned some new tricks about the G500T. I don't know about the 5000 settings, but that gyro is not as good as the 500T according to people I know and trust that have flown it.

If you use your radio in Std mode, and the particular channel you are using can achieve +/- 150%, the ACTUAL gain setting on the gyro is 1.5 x channel endpoint setting.

If you use GY mode, the gain is what you set on the display.

ALSO, I was wrong about the subtrim portion of my bantering before. Apparently JR allows subtrim to take out minor tail drift. This is a cool idea and it makes setting up the gyro and heli tail that much easier.

My G500T has been through many flights on my JR Voyager 50 and it is THE best gyro I have ever owned. In backwards flights, tail slides, backwards loops, backwards rolls, etc...this gyro just holds. My Futaba GY401 and 501 couldn't even come close to this performance. The 601 should be able to, but the complex setup, size and multicomponent design, plus the enormous cost of it are just too much for me to swallow.
By the way, I am replacing another Futaba gyro with another G500T this week.

Good Luck and I hope this helps you with your setup.

03-30-2004 Over year old.
cjss79

Heliman

bloomington,il

I expierenced something weird with my tail today, after the engine had quit running i went and picked up the heli and my tail rotor was moving left and right so fast the tail was vibrating. I am running the JR8417 servo. I know a lot of people have had bad luck with it, but others feel its a great servo? After reading your information , I discovered i have mine set up wrong also. I was just wondering if anyone has had this problem or should i set it up right and go from there.

boom135 what tail rotor servo are you running in your heli(s)?

04-03-2004 Over year old.
cjss79

Heliman

bloomington,il

opps... 135boom

04-03-2004 Over year old.
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