[HAL9KPCM]

Factory setting of 80%... I'll try dropping it to say 75? Probably give it another fire tomorrow... it's a little cool out and I need to let the nerves calm a bit LOL.

[HAL9KPCM]

Finally got back on it... 75%, still wagging... 70%, wagging less, 65%, starting to wander.. 68% seems just right.

[Cougar429]

That seems a little on the low side. Is there any vibration from the tail rotor? Usually shows up by blurring of the tips of the horizontal fin once at speed.

Also, is the gain channel ATV set to 100% both directions? If above that then you will get a false indication of the real gain setting.

However, only your flight tests will confirm if the tail holds to your satisfaction. Don't forget an adequate head speed is mandatory for many reasons.

I did not mention this in the original post, but from what I can gather most gyros will peak out at 10% away from maximum channel gain reading. What this means is, with a channel readout of 0-100% full sweep the gyro will be at peak HH with the gain set to 90% and peak RATE with the gain reading 10%. Any further away from the center point will do nothing. If this is correct then your 50% gain point in HH would show 70% on the display and 50% RATE would be 30%.

Some transmitters will display the gain as a 0-100% either direction away from that 0% center channel mid point. In this type the math would show max gain at 80%.

Don't know why this is the case.

[HAL9KPCM]

The heli is running smoother than anything I've ever previously run before. Since it is a larger machine, I took my time with the main rotor balancing and tail balancing. The gain channel ATV is 100% both directions.

In the end... like I said at 70, there was a very tiny wag... less than an inch total... at 65.. the nose seemed to wander slightly, nothing uncontrolable, just with various throttle positions the nose heading would change slightly... added a tad more and it seems totally solid.

[cool pool]

Hi,I'm having two problems with a Futaba GY401 gyro. First on the gyro rate for 0 and rate 1 .Have a setting of 80% for switch position 0 and a setting for one is 60%. I'm setting up a Blade 400 and using the DX6I.
I've noticed when going from position 0 to position to one on the TX the LED still stays a solid red on the gyro. Do I have the rate for position 0 too high ?
Second, I must have a brain cloud, when reading the GY401 functions, I'm confused with the DIR / DS switch. With the Blade 400 the direction of the main rotor is clockwise and the tail rotor is counter clockwise. The servo for the tail rotor is the S9257. Question, which way do I select the switch on the gyro to DIR or DS ?
Any thoughts on this would be very helpful.
Thanks in advance.

[Cougar429]

Had to go have a boo at the programming on that radio, but have to admit the gyro function settings are not really well described and I do not have one in front of me to experiment. You may have to do that to confirm some suspicions.

If you have access to the Ch 5 output on the Rx try plugging in a servo in place of the gyro gain. I recommend this since I believe BOTH settings are still in the HEADLOCK side of neutral.

With the servo plugged in see if switching modes has the servo swing from one side of neutral to the other. I suspect that 60% in Pos 1 would keep it in HH mode, just with very low gain.

If you do not have that option, try setting position 1 below 50% to see if the light goes out. Just ensure you always power the gyro up with the switch in HH mode, even for this test. Only once initialized try that lower setting switch position. I do not believe if the 401 is powered up in RATE mode it would then go to HH mode adequately and the light may not come on at all.

As for the DIR/DS, these are two separate switches with discrete functions.

DIR sets ONLY which direction the corrective signals from the gyro are biased. This will not affect inputs you make from your transmitter. You can test this before even spinning up the rotor by initializing the gyro and then rotating the body of the heli. If looking down from the top you spin the heli nose to the left, (CCW) you should see the gyro try to increase the pitch of the tail rotor leading edges in toward the boom. I believe this would pull the pitch link to the servo forward. Not 100% sure and my "Caffeine Low" light is on. Basically what you are looking for is if the gyro corrects in the proper direction. If not things get entertaining in a real hurry if you try to fly.

The DS switch sets the output frame rate sent to the tail servo and is for analog or digital servo options. With that switch turned ON you are on high frame rate and should ONLY have a digital servo plugged in. You can quickly fry an analog servo trying to keep up, (don't ask). You can run either a digital or analog servo with it turned off, but are not taking advantage of the faster response time available to digital servos.

NOTE: The 9257 is a digital servo so the switch should be up, or ON. The only limitations I found was for input voltage. Both servos are close in specs, but the 9257 has a max limit of 5V, whereas the 9650 can run as high as 6V. Since I run the swash servos on mine at 6V for better torque and speed this allows me to avoid adding a voltage limiter just to the tail.

p.s. The 9257 was a bit quicker and there was a bit of a cheat we used with the 9650. By switching the two center gears in the 9650 with those from a 9257 gear set we could get quite a bit faster response with very little drop in torque.

Hope that helps. Let me know what happens with that gyro gain setting. It's been quite a while since I played with the 6i and none of my group still own one to test.

[cool pool]

Thanks Cougar 429, your suggestions were very helpfull. For the gyro rate I changed switch position 0 to 70% and switch 1 position to 49%. With that now when I switch from 0 to 1 the LED turns off.
As for the DS/DIR, placed the DS to the on position and the DIR to the reverse position. Thanks for the tail rotor check, the leading edge in when moving the helicopter to the left, I had it backwards. Now I know what you meant that the flight would be interesting, try to turn left and it would turn right.
Also I noticed when moving the tail rotor left and right with the TX that I wasn't getting an even blade angle between the blades, the tail rotor pitch control slider ring was hitting the the screw for the right hand tail rotor case. Then adjusted the scew on the tail rotor linkage and set the pitch control slider ring to neutral. And now the tail rotor blades move evenly both left and right. Got a little more work to do on the helicopter, I'll let you know how things work out. Thanks again

[Cougar429]

What I meant by "entertaining" was that when the gyro sensed rotation the corrective signals generated would accelerate the spin, rather than counter it. You would be surprised how fast they can rotate about the main axis when full over.

With the 401 you can set the total servo sweep range with the "LIMIT" pot on the gyro itself. This also influences your transmitter input, so do not try and control the servo movement with the ATV or TRAVEL option in your Tx parameters. Leave it to 100%. The reasoning for this is that if you did, the gyro itself could still send corrections that could overdrive the servo to mechanical bind. By having that set by the gyro you limit the servo travel under any condition.

Also, ensure you do not have any throttle/rudder mix enabled. For some reason that holdover from before effective and inexpensive gyros came on the market remains available within a lot of the programming options. It is not needed, nor wanted, (it basically tried to compensate for variances in torque with different throttle/pitch inputs). A properly set up gyro and tail servo will do all that automatically.

[mrrandyman]

I have been bitten by the Heli Bug and have two. The first is a Blade 200SRX and it is a ball. The second one is the Blade 500x w/7200bx BNF and can not get it programmed properly into my 9503 Airplane mode radio.

I have followed all the instructions but for some reason I can not program the gyro to the Gear switch on my radio.
I have spoken to or emailed a couple other people and have been told that the 7200bx uses the Gear channel by default to control the gyro but won't or can't tell me how to program the radio to use the gear switch for that purpose.
So what I am left with is a helicopter that won't hold it's position when I spool it up on the ground and wants to spin around.
If I input rudder to compensate it will continue to rotate in that direction even when I neutralize the stick. The same happens in the opposite direction.
Should the tail rotor not zero it's self out when I am not making any stick input?
I have a DX7 Airplane Mode radio also that I tried to setup with the 500x and it has the same issue.
I'm almost tempted to buy a Heli radio but am determined to try to use my Aircraft radio for the time being.
I hope I have given you enough info to help me.

Randy

[Cougar429]

Not familiar with that system so not able to offer any direct advice, although unlike my 10X that is aircraft only, yours at least has heli programming resident with the rest. It`s just the switch/pot/slider names that I find different between one version and the other.

I may be able to help you find a general solution.

First off, depending on the mode the tail servo may return to center or remain over in the last direction you commanded. Normally, RATE mode will return to center as this is a direct command for the gyro to look for any turn RATE you ask for. If the stick is centered it will look for whatever turn rate was present at the time the rudder channel went to neutral.

That may sound a bit confusing, but think of it this way; the gyro is looking for "Rate of Acceleration", not rotational rate. If the stick is anywhere but neutral it is looking for either an accelerating, (increasing) rate of turn or decelerating rate of turn and it all depends on a difference in the amount between one signal frame and the next.

Let's use an example. The heli is hovering in a stable attitude and heading. You input rudder for either direction. The gyro sees this change and moves the servo to have the heading change accordingly. Once it sees the signal steady out it will try and have the heli maintain that rate of turn. It is only if it sees an input signal shift or a change in the rate of turn, (from external forces) will it work to correct it. Even if the heli is spinning like a drill bit, if the rudder stick is centered it will continue to hold that rotation rate. It will continue until you command a change in that rate.

If the heli is sitting on the ground the rotation rate will be stable regardless of the rudder input, so the gyro will have the servo follow your imputs directly and immediately.

Heading Hold will look different, especially if sitting on the ground as it is looking at the rudder input signal and trying to match whatever you last requested from neutral. If you input left stick, (even a touch) and release, the servo will continue to move further into that direction as it is looking for and not seeing any heading change at all and will work harder and harder to make it happen. This is why you want to set the servo travel with the gyro as this can continue until hitting mechanical stops, (and causing damage to the linkage). If allowed to continue against a physical stop the servo can overheat and fail.

Now, back to your system. One way that may make your changes more evident, (and one I often used until I understood my new transmitter programming setups, is to plug a servo in place of the gyro gain lead. This will give you direct feedback on what your changes to the Ch 5 output programming are doing.

I found on mine that 3 positions was often a big help as it allowed for one RATE gain setting and two HH settings. As I only used RATE for initial flight setup to show if the tail servo was at or close to the optimal center position for hover, I then would fly exclusively with HH for the rest. If I found the tail too twitchy or had an oscillation, (usually the result of vibration effects) then I can back it down a touch by selecting the center switch position.

So, what you would expect to see would be the servo to one side of center for RATE and to the other side in HH mode. The further away from center the higher the gain.

What also may help is a video I found directly relating to the 9503 and 7200bx:

https://www.youtube.com/watch?v=gwOJNK0uAs0

Just gave it a cursory glance, so let me know if that works out.