Hi Nigel,
My main concern with this mod would be the insertion of the (predrilled)
15mm discs into a tube with anti-corrosion paint on the inside. Would there
be a suitable reamer to get it absolutely smooth, also to remove any burr
---From the enlarged holes. Then how do you aim to position the discs so that
all the holes line up ? Maybe a threaded hole in the centre for attaching a
long rod temporarily just for the lineup ?
Karl
>From: "Nigel Graham" <nigel_graham@btconnect.com>
>Reply-To: europa-list@matronics.com
>To: <europa-list@matronics.com>
>Subject: RE: Europa-List: Tailplane flutter
>Date: Mon, 25 Jun 2007 11:29:20 +0100
>
><nigel_graham@btconnect.com>
>
>Hi Graham,
>
>FYI - I am working with Ian Rickard at the moment to document exactly what
>I
>did and present this to the PFA.
>
>To enlighten those of you not familiar with this mod:
>A long time ago I identified the inherent shortfall with the TP14 method of
>securing the drive arms to the torque tube. Merely replacing these pins
>with
>oversized pins would not in my opinion, cure the problem - only delay the
>next re-occurrence once play developed.
>
>I developed a simple arrangement (KISS technology) that positively clamps
>the drive arms (TP9 and TP12) onto the torque tube by replacing all four
>TP14 pins with 1/4" x 2.125" AN bolts.
>To support the torque tube and prevent it distorting, 15mm wide
>cross-drilled discs are inserted into TP4 at each of the four stations.
>To spread the clamping load over a larger surface, "saddle blocks"
>(profiled
>to mate with the OD of TP9 and TP12) are fitted under the bolt head and
>castellated nut.
>
>The beauty of clamping is that it introduces a torque damper into the drive
>system - eliminating the shock "chattering" that wears the standard TP14
>pins and elongates the holes - and it can be retrofitted to tubes with worn
>holes.
>
>Nigel (The other one) Graham
>
>
>-----Original Message-----
>From: owner-europa-list-server@matronics.com
>[mailto:owner-europa-list-server@matronics.com]On Behalf Of Graham
>Singleton
>Sent: 25 June 2007 00:25
>To: europa-list@matronics.com
>Subject: Re: Europa-List: Tailplane flutter
>
>
><grahamsingleton@btinternet.com>
>
>Carl
>The torque tube is chrome plated 4130 I believe, stainless isn't strong
>enough.
>You may have spotted the weakest link in the chain, if the TP9 & 12 had
>more bearing area the slop problem might go away. Wouldn't be much
>weight penalty either.
>OTH clamp bolting as Nigel Graham did years ago might be the best answer.
>Graham
>
>
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