Shaun,
I had your problem in its entirety! The most important two thing is to;
1. Ensure the Torque Tube is horizontal with the front of the airframe!
2. Ensure the distance from the front of the airframe to the end of the torque
tube on each side is equal!
Then the aircraft will fly straight in both Lateral and Vertical planes.
I opted to leave the inherent twist in the canoe as these measurements COULD BE
altered once the jig holding the
canoe in place is taken off or the aircraft may tend to revert back to its
twisted "natural" state. Debatable I know, however
the result of the twist, if left in, is small (in my case) and can be covered
cosmetically to ones satisfaction.
Cheers,
Tim
Shaun Simpkins wrote:
> All right, this is getting confusing and putting my SHORTS in a twist.
> If I go out and measure my raw fuselage bottom, the port stablilator
> fairing is at most 1/8" forward of the starboard fairing.
> The port torque tube crosshairs are 1/8" higher than the starboard
> relative to the tops of their respective fairings, but are equally far aft
> of the nose of the fairings.
> I haven't checked the waterline, nor the vertical displacement of the
> fairings from the waterline. Let's assume that they are the same for
> now. If there is no twist and you drill on the crosshairs, your stabilators
> willwind up with the port end skewed forward and up, and the port root
> 1/8" higher than the fairing. If there's a twist, it could be horizontal,
> but
> still out of line with the fairing and still vertically misplaced.
> Untwisting
> a pure longitudinal twist could make things worse, since the crosshairs
> are misplaced vertically.
> So from what I see, the proper procedure would be to:
> 1. untwist the tail cone ( and hope that the twist is purely about the
> longitudinal axis ) if warranted.
> 2. measure aft equal distances from the firewall for the torque tube
> centers.
> 3. measure up equal distances from the waterline for the torque tube
> centers, but adjust to equalize any misalignment with the fairings.
> There's another argument about whether twisting to align the tail is bad
> from a structural point of view...
>
> Shaun
> A207
>
> ----- Original Message -----
> From: "Miles McCallum" <milesm@avnet.co.uk>
> <europa@avnet.co.uk>
> Subject: Re: Tailplane to root fairing alignment, -and servo
> pins
>
> > Longitudinal position is fine - vertical position isn't - if you "untwist"
> > the tail end in a jig...
> >
> > M
> >
> > > Forwarded from the bounce bin. Message is from
> > > "Cliff Shaw" <dm25shannon@home.com>
> > >
> > > ****************************************************************
> > >
> > > All
> > >
> > > I just went out in the shop and made a mesurement on my taleplane torque
> > > tube. It is 141.5" from the front surface of the fire wall to the front
> > > surface of the torque tub at its outboard end. Both P & S sides are
> > exactly
> > > equal. My installation was done on the scribed X points. It turned
> out
> > > right on the MONEY and I am happy.
> > > Cliff Shaw
> > >
> > >
> > >
> >
> >
>
--
Timothy P Ward
12 Waiwetu Street,
Fendalton,
Christchurch,
NEW ZEALAND
Ph. 0064 03 3515166
email ward.t@xtra.co.nz
Mobile 025 2649325
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