Re: Motor stick sideways bow?

From: Jake Palmer <82.jake_at_gmail.com>
Date: Mon, 5 Nov 2012 13:32:15 -0800

My guess is the sideways bowing is because the stick is twisting. I
believe 2 bracing wires spaced apart will help with twisting to an extent,
but it might not eliminate it.


On Mon, Nov 5, 2012 at 10:48 AM, Tapio Linkosalo <tapio.linkosalo_at_iki.fi>wrote:

> **
>
>
>
> I have been recently working on my new F1M model. Initially it showed a
> tendency to fly rather flat in the start, and this turned out to be too
> loose rigging line, letting the stick bow, increasing downthrust and
> reducing decalage. Tightening the line helped, now the model even tries
> to stall in the start.
>
> However, in the latest trim session I noticed that the tube now bows
> sideways under full motor load. I have never seen such behaviour, and it
> seemed so alarming that I decided to abandon flying that model before
> strengthening the tube. I have not made up my mind yet: adding boron
> would be the easiest way, but (to show the simplicity of the models to
> our Finnish newcomers) I'm more tempted to replace the single rigging
> wire with two, at an angle.
>
> Anyway, my question is if this bowing is due to too stiff a rigging
> wire, as the bow seemed to start only when I thightened it? I have been
> trying to figure out the loads and geometry of the rigged stick; if the
> support point in the middle is brought below the support points at the
> ends, would this make the setup such that the setup is unstable
> sideways? Thus, would only loosing the rigging slightly end the bowing?
>
> -Tapio-
>
>
Received on Mon Nov 05 2012 - 13:32:16 CET