Zeal blades + low headspeed setup?

[madeye]

I decided to try a different set of blades (ZHM-350R) instead of Radix I flew for a while. Now having pitch oscillations in forward flight, guaranteed, and, interestingly enough, sometimes in hover as well.

The first observation from more experienced pilots was that since these blades are much lighter, cyclic elevator gain needs to be lowered. Next time I was flying, I did lower the gain a bit, didn't help. Maybe I didn't lower it enough (didn't want to overreact and wanted to see how the behavior changes), but then another pilot made an observation that this may be due to the lower headspeed I'm running (2100RPM).

So the questions are -

- When you have oscillations, what's the percentage of gain change that makes a difference? 5? 10? 25? 50?

- Given there are no other telltale signs of the headspeed being too low (the infamous "wobble"), can this be related to low headspeed, or it's just the gain is too high?

- What other malfunctions can cause pitch oscillations?

- Are Zeal blades indeed that much lighter than others? I've flown the stock MSH, Lynx (which are essentially the same with a different brand on them), two different Radix (FB and FBL), and never before I had to touch cyclic gains.

[jmtyndall]

Loaded questions

The amount of gain change required is based on the fbl unit. 5 points on my fbl could be 50 on yours

Zeals aren't lighter. They are stiffer, this often requires a gain adjustment

[madeye]

Originally Posted by jmtyndall

The amount of gain change required is based on the fbl unit. 5 points on my fbl could be 50 on yours

Sorry, should've mentioned. It's the Brain. Default elevator cyclic gain is 40, I dropped it to 37, if I remember right (can't look right now, away from it).

[madeye]

Update: Looks like blades are irrelevant for this problem. Changing them back to Radix didn't change the behavior. More: https://www.helifreak.com/showthread.php?t=704873