9303/G500T/8700G Setup Tips?

[rob_jones]

I want to try out the JR G500T gyro and 8700G servo combo on my 9303. I've heard good things about them and found a good deal on a combo. I've used the setup guide for the Futaba 601 on JK's web site and it works great for me. I haven't found a similar guide for the 500.

I actually broke down and read the directions and it looks very simple, but I don't know what a good starting point for the gain would be, or if there are any other tweaks I should know.

TIY, Rob

[marked23]

I'll have my 9303 tomorrow (just bought one), but I use the 8103 right now and it's likely the same.

I have a Hawk set up with the G500T and a 8700G.

In the [GYRO SENS] menu you can set the gain.

100 is full HH gain
50 is No Gain
0 is full Rate gain
A good starting point is 75HH or 25rate. I'm using 72 on my Hawk.

If you use the gear switch, then the numbers go -100 for rate and +100 for HH... in that case a good starting point would be 50 on either side.

The screw setting (pot) on the gyro sets the limits. Set it so that it doesn't bind at full stick movements.

Your ATV for the rudder stick controls your max piro rate. I set that down to about +/-75, but this value floats around as you mess with the gain setting. The more gain you have, the more ATV you need to get the same piro rate.

For more info, read the sticky messeage in this forum http://www.helifreak.com/about4373.html It covers more details like how to mechanically set the centering. I never bothered and still had great results.

-Mark

[bigrcr]

Here is a decent starting point and why for your 500T/8700G/JR9303.

-First Install the gyro as normal. I prefer the 3-M (clear) double sided tape (I get mine at WalMart) to mount the gyro. The stock stuff will deteriorate quickly and come apart, then your bird takes a BAD ride :badair: .

-Plug the rudder into the receiver directly and make sure that the rudder goes the correct way.

-Next, Plug the gyro into channel #4 (rudder) and the rudder into the gyro. Next plug the mode connector for the gyro into channel #7 (Aux #2).

-Go to the "Device Select" menu and ensure that Aux #2 is on "flight mode" switch and "Gyro" shows up below it.

-Set the Rudder Travel Adj to 150% each way. This sets the sensitivity of the gyro to it's optimum position.

-Set Rudder D/R to 70% or a little below. This will set the pirro rate (if left at 100%, a rudder command will spin the model so fast you may blow a crown gear or break something).

-Set Rudder Expo to 45-50%. This sets how quickly the gyro reacts (how hard it hits).

-Turn on the system and set the gyro sense (make sure the gyro is not reversed).

-Go to the "Gyro Sensitivity" screen and set Position #0 to 70-75% (this should be HH) and Position #1 to 28-30% (this should be normal Non-heading hold). To see if you have HH or not in the correct mode, hold the rudder stick to one side and let go. If the rudder follows the stick and returns instantly back to center you are in NON- HH mode.

-First flight. Switch the gyro in the "Gyro Sensitivity" menu to non- HH position in normal flight mode and set the tail rod mechanically to hold the nose of the machine steady without pulling to either direction.

-Set the "gyro Sensitivity" to HH mode and go fly.

NOTE: If the model drifts at all (it will actually be pulling to one side or the other, not drifting), use the rudder sub trim to stop the movement. This can be done on the bench if the rudder creeps to one side or other. YES, you can sub trim the rudder!!!

When flying make sure that the tail does not wag in FFF. If it does take out a little gain in the "Gyro Sensitivity" menu.


Hope this helps!!


-

[rob_jones]

Thanks, guys! I printed this page and will take it home with me when I do the initial setup. I'm looking forward to trying this system out!

[rob_jones]

Oh, and I also printed the Word doc from the thread linked above. I wonder why JR didn't see fit to include any of that info in the instructions?

[bigrcr]

By request from Horizon a couple of years ago, I wrote a set of Instructions including diagrams for the 500T gyro. The instructions were supposed to be changed so that pilots could actually use them. It's a shame that they did not do better or the gyro would be far more popular than what it is now as it is a superb gyro. Most pilots don't want to mess with it since the instructions are SEVERELY lacking. :arggg:

Later,

[Kenna]

-Set Rudder Expo to 45-50%. This sets how quickly the gyro reacts (how hard it hits).


Is this really correct? Doesn't expo on rudder effects how sensitive the stickrespons is around midstick, how can the gyro now if it is you that i s really smooth with the stick or if there is expo, and if you don't even touch the stick, how can the gyro read if there is expo or not? :roll:

[bigrcr]

The setting for the gyro on expo is not seen by the gyro as exponential. It is seen as "damping" for the pirro rate.

Later,

[Kenna]

Ok, this is totaly new knowledge for me, I have 3 birds with this gyro but they all worked well but I'll try to experiment with this to get even better performence :lol:

Thanx for the info