All:
Let’s be careful about what we are saying here. The bob weight in the LNC2 control system is a classic “forward bob weight” its location in the longitudinal control system is as if it were attached to the front of the stick on an arm. Its purpose is to resist the onset of g forces by making the stick harder to pull aft. Its purpose has nothing to do with flutter.
Actual control surface balancing is done with the over balance extensions on the outer edges of the elevator. I do not think it is wise to fiddle with the bob weight, remove it, or alter its mass.
I have a Trio autopilot in my LNC2 and it is “nervous” in pitch control, especially at the more aft allowable CG’s. I use a nylon collar to attach the linkage to the pitch servo. I believe I have a little too much lash in that linkage and need to tighten things up.
Regards,
Pete Field
LNC2, St. Louis
From: John Barrett [mailto:2thman1@gmail.com]
Sent: Tuesday, March 18, 2014 9:41 AM
To: lml@lancaironline.net
Subject: Re: [LML] Autopilot servos and L360 bobweight
Bob weight is there to balance the control surface . Out of balance can carry risk of flutter. Be sure to research before changing that relationship.
My Tru Trak autopilot altitude hold is inconsistent, and opinions are that the servo had difficulty working properly because of the mass of the bobweight on the elevator idler arm. One possibility is to remove the weight and expect more pitch sensitivity (lighter stick force) in turns. Has anyone found other alternatives?
What if the mass of the bobweight is reduced?
My servo is behind the seat and connected to a ring clamp on the elevator control tube with a smaller, roughly parallel, rod with bearing ends.
Jack Dysart