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E-flite . Next D . Fast Lad Performance

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Radio - Servo - Gyro - Gov - Batt > gy401 travel adj.
 
 
SRXripper
Senior Heliman
Location: ocala, fl

on intial setup on my evo, you set the servo limit wtih the gyro, not the tx. -atv's100%. now the problem i have is the when i move the rud stick to 3/4 the max travel is met. But if i continue pass 3/4 stick it doesnt bind nor does the servo move, now that should be correct do to setting the limit on the gyro. so now my tx has about 1/4 of max stick movement that does nothing.

playing around I decreased the rud atv's to where i have full range of servo and stick movement

is what i'm doing correct?

jr8103 gy401 9254

EVO50, OS50, JR8103DT, 9252's, Gy401/9254
02-22-2005 Over year old.
 
 
Drunk Monk
rrProfessor
Location: Preston, UK

The ATV's only control the piro rate and have nothing to do with the amount of travel of the servo. What you are describing is normal. When the heli is in the air, the gyro will behave normally.


Stephen

I only open my mouth to change feet.....
02-22-2005 Over year old.
 
 
Dr.Ben
Elite Veteran
Location: Richmond, VA, USA

Put the ATV's back to 100% and leave them there. Put the gyro in HH mode and adjust the limit so that the linkage goes full travel with no binding. Your final piro rate will be set with the AFR or rudder d/r, especially with a Futaba transmitter.

It is normal behavior for a HH gyro for the servo to not exactly follow the rudder stick position while the model is on the bench. The limit function avoids binding up the system when you carry the model about and otherwise sets the maximum travel for the system. The actual position of the servo in flight is determined by where the gyro thinks the servo needs to be to yield the desired yaw rate.

Ben Minor
02-22-2005 Over year old.
 
 
Capt. Bly
Heliman
Location: Whiteoak, TX

Ditto

I just talked to Al Magaloff about this same problem with mine. I bought an 8103 and put in a new receiver (Spcm). Mine is even more pronounced. I just barely take my stick off center, maybe 1/8th to 1/4 of the available stick travel and the servo zips to full travel. It is not binding or anything it just goes right to the travel it is setup for.

I'm pretty sure it is doing the same thing in the air because I hovered it the other day after getting a GREAT Lesson from Al on a quick 401 setup and it was very touchy on the tail. It is acts this way in both HH and Normal Modes.
02-23-2005 Over year old.
 
 
TMoore
rrProfessor
Location: Cookeville, TN

Ben is right about the 401 setup. I use an ATX radio and I'm running the longest Futaba arm you can buy. The gyro limiter pot is set for no binding. The rudder ATV's are set to anywhere from 90% to 115% depending on the gyro gain and the desired piro rate. I use the gyro program in the ATX Stylus and I'm running about 50-60% gain. This equates to about 40% on a Futaba TX.

With any HH gyro you no longer are in control of the tail rotor, you now must fly the gyro. In HH, this is the way it is. That's why you seem to run out of travel at around 3/4 stick. Flick the tail rotor stick back and forth 3 times and the gyro will re-center the tail servo just as if you flicked the switch into rate mode. If the tail servo drifts after you do this something else is wrong like a subtrim or center adjust is in force.

When you boot up the gyro, the AVCS light should stay on steadily after the initialization flashes are over. Like Ben said, you really need to have the 401 airborne to see how it works and the bench won't show you much of anything.

TM
02-23-2005 Over year old.
HOMEPAGE  
 
 
stevenpph
Heliman
Location: Phoenix, AZ

Here's a neat way to think about it. Your rudder stick no longer commands the rudder's degree of deflection - it now commands the piro rate. Move the stick 1/4 of the way and you're commanding 1/4 of the max piro rate. Since you are on the ground, the gyro detects zero yaw rate - so it will move the rudder a whole lot. Maybe a perfect HH gyro would move the rudder to max left or max right whenever you touch the rudder stick while on the ground.
02-23-2005 Over year old.
 
 
Capt. Bly
Heliman
Location: Whiteoak, TX

What about in normal mode though?
02-23-2005 Over year old.
 
 
SRXripper
Senior Heliman
Location: ocala, fl

so how do you adjust the yaw sensistivity?

EVO50, OS50, JR8103DT, 9252's, Gy401/9254
02-23-2005 Over year old.
 
 
TMoore
rrProfessor
Location: Cookeville, TN

Use the gyro gain program in your radio or use the ATV/EPA on a gear channel that is switched.

If anyone wants to fly in rate mode, be my guest, I don't.

TM
02-23-2005 Over year old.
HOMEPAGE  
 
 
SRXripper
Senior Heliman
Location: ocala, fl

i thought the gyro gain only helps how well the tail holds!? but what your saying it adjust how fast or slow the tail moves.

EVO50, OS50, JR8103DT, 9252's, Gy401/9254
02-23-2005 Over year old.
 
 
TMoore
rrProfessor
Location: Cookeville, TN

OK, here is what I do.

Adjust the gyro gain to a level like 40-60% depending on the radio. Basically if the tail holds and doesn't wag then the gain is somewhere in the ballpark. Once you have the gain close, the piro rate is adjustable with the tail rotor end points. The higher the endpoints that faster the heli will pirouette. If you use a Futaba radio use the Dual Rates to adjust the endpoints because different end points on the Futaba radios change the tail rotor center pulse on the TX and this will cause an out of trim condition. This is per Ben Minor. ATX doesn't exhibit this issue. I'm not sure about JR as I haven't tested it. Dual rates alleviate this issue.

Once you get the piro rate to a level you can live with then back off of the gyro gain until the tail won't hold in the maneuvers that you want to do, then bring up the gain a little. For instance if you do forward and backward flips and you see the heli rotating as you flip the machine, make sure you aren't inadvertently putting in rudder input as you do the maneuver, increase the gain until you get the tail to hold nicely. Backwards inverted is the same. Increase the gain until you get the tail to hold.

Bear in mind that if you get the gain to ridiculous levels that you will have to increase rudder end points to get the piro rate back. As the gyro gain goes up, so does the workload on the servo so you need to balance it out with adjustment of the gyro gain and stiffer tail blades like carbon blades. It is easy to tell if the servo is over worked due to the gain being too high by taking a heat gun and measuring the heat of the servo at the motor end. The temps should be around 120 degrees F.

A 401 won't hold like a 502 or a 601, so don't expect it to be flawless in all sorts of wild aerobatics because it won't be. Piro rate consistency is harder to achieve on a 401 so you really have to balance out the overall gain and the tail rotor endpoints. When you get the adjustments to the point where they are about as good as you can expect it will seem like the tail rotor is very smooth and seamless when you go from no tail rotor to full deflection. IOW it will seem to feel smooth with no sudden wild change in piro rate when you get to full throw.

TM
02-23-2005 Over year old.
HOMEPAGE  
 
 
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Radio - Servo - Gyro - Gov - Batt > gy401 travel adj.
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