N5C vibration. Help!

[Will Campbell=Crashr30]

It is both the Aileron and Elevator Expert Menus.  I assume you are running 1.2 software?  If you are on 1.0 or 1.1  then the value can not be changed. 

If you can not change then do not worry about until you are ready to update the software.  I would not update just to make this change if you are happy with the machine flys.

[flyboynellor]

My 750 is the 1.1 version. I agree with you on the upgrade to 1.2. Not worth it. I'm going to up my HS to 1950 and not worry about the shaking. I've decided over the winter to replace the engine bearings for next year. Can't hurt. Thanks for all your help resolving this problem.

Merry Christmas
Bob

[Will Campbell=Crashr30]

Enjoy and glad I could help.

Merry Christmas!

[Matt Botos]

flyboynellor,

Some of this may have been stated already so sorry if I am repeating.

The OS55 (depending on the pipe) is in its power band at around 17500 - 18000rpm. With that in mind the N5c gear ratio is 8.5:1 which means at a minimum you should be running 2050 on the head. Most people are getting peak performance around 2150 on the head. If you choose to not run 2150 on the head, read below....

I designed the dampers to create a very rigid head. This is optimal for performance of the 750 and other FBL systems in hard 3D with peak power head speed of 2150. If you would like to run a lower head speed, you may want to try different shimming options on the head dampers to relieve compression and allow for more damping. Make sure you grease your head axle and dampers so that the head centers freely.

Keep in mind, I designed the N5c to handle the stresses of todays hard 3D. It can be flown in more of a "sport" configuration but stock out of the box it's configured to be driven like a race car.

Hope that helps!

Matt

[Jake]

Another thing to try, if you're willing, is to turn up yourI Gains in Aileron and Elevator expert menus.

I had the exact same issue on the first flight of my CGY750. I found it was a combination of headspeed (as I first experienced it at 1600, and to an extent, right up to 2050) and I gains. Bringing the headspeed up to 2150 helped a lot, but when the engine loaded, the heli would shake, which is where I turned up the I gains. I think the default is about 35, mine are now at 75.

Flies perfectly, smooth and locked in now.

Hope that helps?

[flyboynellor]

Thanks Matt and Jake,
I have increased my HS to 1950 in normal mode and 2000 in stunt mode. Just increasing the HS by 100rpm eliminated the shaking. I will further increase my HS up to 2050. Jake I also ran my I gain up to 45 on both aileron and elevator. That alone didn't cure my shaking. The HS increase accomplished that. It's OK to run the I gain up to 75? Whats the down side of too much I gain?

Thanks guys

[Jake]

Hey mate,

I can't comment on the effect of running the I gains *too* high, as the highest I've run mine at so far is 75. I think it just alters the overall feel of the cyclic, but I'd have to experiment with that to say it in confidence..