atrr

Please help w/ Align gyro causing tail on T-rex 450x to waggle back and forth in hold heading mode. I'm using Futaba 7CHP. Need setup help.

tanasit

This is a the copy from my recent post: Hope it applies to Align Gyro too.

The 2 terms being used on the all in one controller are similar to GAIN and PROPORTION on the other controller.
The GAIN or LIMIT will set the strength or sensitivity of how much the rudder response to the yaw movement, normally set at 90% and go down from there.
The PROPORTION or DELAY will dictate the amount of signal sending to the rudder control per unit time, again good starting point is 90%.

The DELAY should be set first, you want to set it so that the rudder speed is proportion to the rotor speed. If the heli is on the ground and the throttle is a lowest position, move the heli side to side by hand, if the tail spins you have to decrease the DELAY.
Then fly the heli and adjust the LIMIT, if the tail osscilates then the gain must be reduced the LIMIT but if you reduce it too much the nose will not stay put.

One manual suggests that you set both at 90% then go down from there if needed. On my Esky 3D, the gain stays around 85% (arrow points at 7 o'clock) and the proportion is about 75% (arrow points at 3 o'clock), this is with 1800 mAH lithium pack.

Look down, the rotor turns clockwise so the body would want to counteract by turning to the left (nose to the left that is), now come the rudder to help pulling the nose to the right (pushing the tail to the left that is). So if you need to trim the rudder to the left (nose moves to right when fly), which means the rudder has TOO MUCH power then you must LOWER the proprotion by turning the pot counter clockwise. If the tail oscillates, then the gain must be reduced (as mentioned above).

If all above still gives the tail hunt, you have to set ATV of channel 5 to lower number. For example, my Futaba GY401 on Trex with Futaba 9Z radio I have to set ATV of gyro (CH 5) down to only 30% to stop the tail waging. Make sure you set this at the higest rotor speed you plan to fly because it will wag more at higher head speed.

It is okay to have to adjust the trim on the TX, sometimes it changes with ambient temperature or the efficiency of the motor(s).

atrr

Thanks Tanasit, it stops wagging now but tail slowly drifts to the left side, is this normal for head holding mode?

tanasit

It is normal especially when just lift off and less when up higher. HH will hold the tail but drift sideway is out of HH control since sideway drift still has the tail points at the same direction (N/S/E/W). If we can have a side drift gyro, then

tanasit

OH, if you mean left yaw, then use the rudder trim to stop it but it may come back when the other factors change like, temperature, low battery power, motor deficiency, belt stretch, ball bearing worn out, etc, etc.

ClemenTang

Anpother possibility is vibration which can cause left yaw too check for any bent shaft. Try to avoid using trimmer for HH gyro.

Clement

disguy2k

You should have it in normal mode if you are just trimming it in anyways.you can't get your trims down as well in HH mode I found. Trim everything in, and get it hovering nicely, then when you're ready for forward flight, adjust up your gain in HH mode (and possibly re-trim the rudder)