5810

Hi i have a newbie question. What is COG mean & what do people mean when they say --- Add counterbalances to the elevator---
what is that, what does it do.

Thank you.

jdetray

COG = CG = Center of Gravity. This is the point where the plane balances, fore and aft.

A counterbalanced elevator is one where a portion of the elevator on either end extends forward of the hinge line. This provides a greater effective area for the elevator.

- Jeff

Scar

My Feedback: (3)

Take a look at the reasons for adding balance area or weight to the elevator. One mentioned, extra area in front of the hinge, reduces the control load on the servo, at speed.

I always think of the situation where your plane drops into a rough landing. Picture the tail hitting the ground like a flyswatter. Then think what happens to the elevator - it slaps down after impact. Now think of the load that puts on your linkage and (more importantly) the servo gear. The way to keep from stripping a servo gear in that situation, is to keep the elevator from slapping down upon impact. The way to do that is to put balance weight ahead of the hinge. Then when the tail slaps down, the elevator - balanced around the hinge - won't deflect.

The same could apply to those barn-door ailerons, too. Good luck,
Dave Olson

5810

Thank you for your replys, but im having trouble understanding the counterbalanced, do you have any pictures of the counterbalanced elevator.

jdetray

This diagram might help. The counterbalance portion of the elevator is the part that extends forward of the hinge. It is shown in light blue in the diagram.

- Jeff

5810

Hi ,so basically the elevator is U shaped??? Is that correct.

is this picture correct

[link=http://members.aol.com:/burninhell5810/abc]picture[/link]

jdetray

Yes, you have it now!

- Jeff

5810

Thank you all for helping out.