I'll start with what I have: Assan GA250 with a HK1518A Digital tail servo. My problem: once the heli gets in the air, it rotates sporadically. I've watched YouTube videos on setting it up but I must have done something wrong. This is my first build so I expected some hiccups. I feel I need to start from square one...
FBL Gyro done all I know how to
- Thread starter yayupp
- Start date
Derek
Well-Known Member
Is the servo horn on your tail servo at 90 degrees to the servo case?
Is your tail slider centered?
Are you sure that the gyro is compensating in the correct direction? Lee has done an awesome tail gyro video. Here is the link:
I hope some of this helps
Is your tail slider centered?
Are you sure that the gyro is compensating in the correct direction? Lee has done an awesome tail gyro video. Here is the link:
I hope some of this helps
Last edited by a moderator:
Thanks for the information! Turns out my gyro was reversed. And of course my battery died while I was trying to figure it all out. Charger gave me a low voltage warning. Just another speed bump. The travel on my tail servo seems excessive/binding. However, when I adjust it on my DX6i, the speed seems to degrade dramatically. Any insight on that issue?
Graham Lawrie
Well-Known Member
Like Lee said, mechanically shorten or re-do the limits in the gyro
murankar
Staff member
Do the limits in the gyro first. Keep your tx limits at 100.
The ga 250 needs a perfect mechanical setup while in rate mode. You want no drift in the tail, or as close as possible.
When adjusting for drift first do the linkage rod until you get it real close, then finish it by doing sub trim. Once the heli hovers without drift then go into head hold mode (dx6i is over 50, start at 65) and hover. Check for shakes or slow wags in the tail. If it is a fast wag then back off the gain, if is a slow wag; appears to be hunting then add gain. Wash rinse and repeat till the tail is solid.
Fir the tail gain I would not go below 55. It's just way to close to no gain which is 50.
Sent from my LG-E980 using Forum Runner
The ga 250 needs a perfect mechanical setup while in rate mode. You want no drift in the tail, or as close as possible.
When adjusting for drift first do the linkage rod until you get it real close, then finish it by doing sub trim. Once the heli hovers without drift then go into head hold mode (dx6i is over 50, start at 65) and hover. Check for shakes or slow wags in the tail. If it is a fast wag then back off the gain, if is a slow wag; appears to be hunting then add gain. Wash rinse and repeat till the tail is solid.
Fir the tail gain I would not go below 55. It's just way to close to no gain which is 50.
Sent from my LG-E980 using Forum Runner
Last edited:
murankar
Staff member
Drift is what the tail is going to do when the set up is nit right. It will either move left or right without input from you. You don't want that while in rate mode. Rate mode is the gear switch on a dx6i or th9x radios and is the off or down position.
(Before doing the next step, there is a good chance that 35 on gain will work on your setup. So the next tuning step may be optional)
The setting is gyro gain and it should be around 35 to get started. Again that number is for dx6i or th9x. Now you may see a slow wag or a fast shake while in rate mode. Do not confuse that with drift. If the tail is wagging then drop from 35 to 20, if it is still a slow wag then drop from 20 to 17 or 15. If the tail has a shake to it then add 5 to the 35, which is 40. I would not go higher then 45 on rate mode.
50 is no gain either way so the closer to 50 the less gain and the farther away is more gain.
Once rate mode is setup then check for drift. Again the tail will move left or right without input from you. (Drift is something that trim will fix) on this gyro you want 0 trim, but you can use sub-trim to get the servo horn center and at 90°.
Now after all that is done you can setup head hold mode in the same fashion.
Sent from my LG-E980 using Forum Runner
(Before doing the next step, there is a good chance that 35 on gain will work on your setup. So the next tuning step may be optional)
The setting is gyro gain and it should be around 35 to get started. Again that number is for dx6i or th9x. Now you may see a slow wag or a fast shake while in rate mode. Do not confuse that with drift. If the tail is wagging then drop from 35 to 20, if it is still a slow wag then drop from 20 to 17 or 15. If the tail has a shake to it then add 5 to the 35, which is 40. I would not go higher then 45 on rate mode.
50 is no gain either way so the closer to 50 the less gain and the farther away is more gain.
Once rate mode is setup then check for drift. Again the tail will move left or right without input from you. (Drift is something that trim will fix) on this gyro you want 0 trim, but you can use sub-trim to get the servo horn center and at 90°.
Now after all that is done you can setup head hold mode in the same fashion.
Sent from my LG-E980 using Forum Runner
Thank you so much for the detailed info. I finally got it to hover without spinning like a top. The relief, happiness, and excitement... I can tell this going to be a good hobby for me. Unfortunately it is bit winding here so I was fighting it more than I wanted on a first flight. I believe I noticed some wag, too winding to detect drift. Battery charging now, can't wait!