sk 540 tuning advice

[jchen]

Hi Guys,
Need some advice. Im still on the 3.4 firmware. Want to tune out the issue before I update.

1. Heli tends climb in ff.
2. In rolls it does the same thing & instead of axial its barrel like
3. In tic tocs heli tends to roll to the left. Thought was my fingers but confirm not.

So how do I go about tuning this out with the handheld.

Many thanks guys

[RontaryUS]

Verify your CG first but v4 firmware solves the dolphin dance behavior in fff. In 3.4, increase hiller gain and decrease hiller decay.

[jchen]

Cg is spot on hiller decay at 110. Will try hiller gain. Strange that when inverted it climbs out as well. There's also a strange behaviour on the gyro. At times the servo will jitter by itself as like when initializing & this is happening on both Sk540. In flight no strange behaviour though.

thks again

Thanks again.

[RontaryUS]

You should upgrade to v4.

What size heli?

For the climbing issue: is you pitch at 0 and swash leveled at mid stick? Is your swash leveled throughout the whole pitch range?

Jitters: what and how are your electronics setup?

[jchen]

Yes Rontary swash is level & through out the range. Both my Goblin 770 behaves the same. Running Jeti Dc 16 with kosmik . Quite unnerving when i see the jitter. Been this way since day one. Again jitter is on both my helis

Thanks again

[RontaryUS]

I have a 770 with Kosmik and Jr servos running with a SK540 and it works great. I may insist but upgrade to v4, at least one heli to see if some of your issues get resolved. V4 tuned out a few issues to me on a couple helis regarding cyclic behaviors...

Re:jitter, do you use the kosmik BEC? Directly connected to SK or Jeti receiver? You kept the toroidal rings on both power cables? How does bus voltage look in the SK log? How are the IBEC and UBEC in the kosmik log? I am thinking at power issues or maybe interferences??

[jchen]

Hi Rotary,
Bec direct to SK . Toriod rings are installed for both master n slave. Never look into the logs. 1 heli is on Futaba n the other is on Savox servos. I doubt its power related. Are u using Jeti as well ?

Thanks

[jchen]

Been searching on Jeti thread. Possibility of jitter might be tx related.

Thks again Rontary

[RontaryUS]

I am not using Jeti. You're good with BEC cables directly to SK and toroids so as you found, it may come down to the receiver (or TX). Posting in the Jeti forum may get you a solution...