Do I need to adjust my gyro gain? - HeliFreak
Fun, Learning, Friendship and Mutual Respect START  HERE

Go Back   HeliFreak > R/C Helicopter Support > 450 Class Electric Helicopters

450 Class Electric Helicopters 450 Class Electric Helicopters manufactured by Align, Tarot, SYMA, Airhog, Chaos, HK and similar.

LinkBack Thread Tools Display Modes
Old 05-06-2009, 05:32 AM   #1 (permalink)
Registered Users
Posts: 605
My HF Map location
Join Date: Apr 2007
Location: Trenton, MI
Default Do I need to adjust my gyro gain?

Hey everyone!

This last weekend, I finally got to really fly for the first time this season. I was running through some simple circuits and everything looked okay, so I went to fly a couple loops and rolls. Everything looked and felt good there, so I popped a few backflips. I noticed that when I'm transitioning to the inverted part of the maneuver (maybe 140 into the rotation), I get a mean little shimmy in the head. It stops as soon as the disc loads up again.

It's my understanding that stiff dampers can cause this to happen (I'm using the Trueblood reds), but this seems like a lot- more than it shimmied last year, at least. I just got done rebuilding the bird and I'm confident that everything is right, mechanically speaking. The only thing that I changed was the tail servo horn, and extended the length by another couple of millimeters.

I'm hoping that it's just improper gyro gain that's causing this shake, because I haven't yet changed the gyro gain since I changed the horn.

I'm using a Futaba GY401 with a Futaba S9650, remotely adjusted from a DX7 with the HH gain set to 73%. I'm using the wheel that came with the servo, and the furthest hole out on it... looks like 8 or 9 mm. Servo specs are ~45 oz/in @ ~.11 sec/60.

I just want to be sure that I've isolated the problem, and if anyone knows or has suggestions about what's really going on here, I'll be happy to hear from you!

Fired up!
Ray K. is offline        Reply With Quote
Sponsored Links
Old 05-06-2009, 12:08 PM   #2 (permalink)
Registered Users

Join Date: Apr 2007
Location: Wichita, Ks

If it's in the head, it has nothing to do with your tail gyro.

Does your RPM drop during this part of the maneuver? If the headspeed is dropping below where the dampers are happy, it'll do weird stuff like this.

Bergen Gasser EB ~ GY611 ~ DS8611As ~ Raja's Jewel Generator \\ RXCharger Free since 2008!
TT Raptor 50 Titan ~ Slowly becoming FBL
BEAM E4 ~ 6s ~ ICE Lite 50 ~ Scorpion 1630KV ~ Spartan DS760 ~ HS65MG/HS5084MG
rccardude04 is offline        Reply With Quote

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

Copyright © VerticalScope Inc. All rights reserved.

SEO by vBSEO 3.6.1