Remember. Any holes drilled in the TP4 tube have to be horizontal.
Vertical holes would weaken the tube too much.
Graham
glenn crowder wrote:
> I like it. I'm doing it this way rather than trying to improve the
> TP6 bond! Thats nuts!
>
> Glenn
>
> > Date: Sun, 15 Jul 2007 22:57:39 -0700
> > Subject: Europa-List: Tailplane retention
> > From: fklein@orcasonline.com
> > To: europa-list@matronics.com
> >
> >
> > Far be it for me, a humble late-builder, to chime in on this very
> > technical discussion thread; nonetheless, in the spirit of "open source
> > communication" with its underlying premise that an optimal solution to
> > the problem will arise out of the clamor, I have a few thoughts to
> > share. If I seem long-winded, my apologies, but clarity is my goal, as
> > I've had difficulty understanding some of the posts of others whose
> > brevity obscured (at least to me) some aspects of their intent.
> >
> > As I look at my "pre-glassed" tailplanes which came w/ my "accelerated"
> > kit, the first thing I notice is that the pip pin recesses as supplied
> > bear no resemblance to the drawings in the manual...at the skin
> > surface, the recesses are round...about 1.25" diameter...and taper down
> > to a .50" hemisphere in which is centered the hole for the pip pin. So
> > I really have no assurance as to what extent the TP6 is properly bonded
> > in or exactly what is going on...I ponder this while reading about
> > variations (such as TP6 location) which others are discovering.
> >
> > As I review Mod 73 and digest the insightful posts regarding the
> > process of accomplishing it, I can't escape my sense that...while it's
> > doable and apparently (at least to those with both the hands-on
> > building skills and technical knowledge to make such an assessment)
> > solves the problem...the mod seems like a bit of a band aid solution.
> > If I understand it correctly, it relies upon a proper bond between a
> > small crescent of a portion of TP6 to some bid cloth which transfers
> > any loads to the skin of the tailplane....I question whether I want to
> > rely on that bond to resist impacts from normal (and sometimes not so
> > normal) rigging.
> >
> > If the fundamental goal is to simply keep the TP12 pins fully engaged,
> > I'm looking elsewhere from the pip pins.
> >
> > I'm looking at the tailplane root close out which, on my tailplanes,
> > looks like about .088" of solid FG skin. I'm referring to the flanges
> > which measure a full inch in width...from edge to innermost surface of
> > the inboard plywood insert with the bushes which receive the TP12 pins.
> >
> > I liked Carl P.'s suggestion (as I understood it) of a hardened steel
> > pin extending thru both top and bottom skins and lying inboard of the
> > TP12 driveplate. The FG flange could be suitably reinforced...perhaps
> > with an embedded plate which could be threaded to receive a threaded
> > rod, thus eliminating fasteners extending beyond the plane of the
> > tailplane surface. I did not understand Carl's calling for the rod to
> > be 9" long, as the depth of the tailplane at the root is just under 5",
> > but perhaps that was a typo. The beauty of Carl's suggestion is that it
> > is simple and direct...it is completely visable anytime the tailplane
> > is slid away from the fuselage an inch or so...and the condition of the
> > "fix" can be monitored at any time in the future.
> >
> > Now that FG flange is only 1" wide, and the TP12 flanges measure 7/16",
> > and the bushes sit 1/16" proud of the glassed plywood...so...after a
> > (let's say) 1/4" dia. hole is drilled for a hardened steel pin to slide
> > past the TP12 drive plate, there's only a 1/4" left of the flange. It
> > would be sufficient however if the flange were reinforced with an
> > embedded plate which would allow the forces to be transferred to both
> > the top and bottom skins.
> >
> > The steel pin could be cut flush top and bottom; perhaps only the
> > bottom plate would be threaded, and the top end of the pin could be
> > slotted for a screwdriver so the pin could be turned in place (and
> > perhaps loctite'd?). For redundancy, there could be two pins per side
> > as Carl P. suggested for the faint of heart.
> >
> > With such a solution, the uncertainties of the conditions of the foam,
> > flox, TP5 placement, and other issues around the pip pins become
> > irrelevant.
> >
> > Amen...thanks for wading through this post.
> >
> > In the time it's taken me to write this, I may well have been able to
> > install Mod 73...and...there's always been more than one way to skin a
> > cat,
> &=========
> >
> >
> >
>
>
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--
Graham Singleton
Tel: +441629820187
Mob: +447739582005
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