The final alignment could be checked by trial fitting the torque assembly
using the shank of a 3/8" drill. The factory supplied pins are a couple of
thou oversize which is probably deliberate. Fortunately we had the help of a
licenced aircraft engineer who loaned his workshop and checked our pins with
a micrometer screw guage. Not sure of the exact dimension but they were
measurably oversize.
Or alternately make dummy pins from 3/8" steel stock - or aircraft quality
bolts. They would need to be checked with a gague to ensure they were the
correct size.
----- Original Message -----
From: "Duncan & Ami McFadyean" <ami@mcfadyean.freeserve.co.uk>
Sent: Sunday, June 24, 2007 2:30 PM
Subject: Re: Europa-List: Tailplane flutter
> <ami@mcfadyean.freeserve.co.uk>
>
> Graham,
> I agree that they loosen up on repeated fitment, yet I had taken great
> care to minimise this during the build (fitting back together only twice,
> less than which was not possible).
>
> As such, unless marginally oversize pins are supplied for the final
> fitting, the design is invalidated by the build process.
>
> Duncan McF.
> ----- Original Message -----
> From: "Graham Singleton" <grahamsingleton@btinternet.com>
> To: <europa-list@matronics.com>
> Sent: Sunday, June 24, 2007 1:12 PM
> Subject: Re: Europa-List: Tailplane flutter
>
>
>> <grahamsingleton@btinternet.com>
>>
>> Duncan
>> I think they always were supplied as an interference fit.
>> I've noticed, however, that once they have been in and out more than once
>> they loosen up. Pushing a drill through to drill the nylon bush is an
>> awful thing to do to an accurate hole.
>>
>> Better way might be to supply the nylon bush pre drilled, then bond in
>> the bronze bushes to fit the position of the nylon instead of the other
>> way round.
>>
>> Re write the plans a bit?
>>
>> Graham
>>
>> Duncan & Ami McFadyean wrote:
>>> Hi all, Remi,
>>> I'm not sure about that.
>>> I had to replace my outer TP pins at 15 hours.
>>> 300++ hours later they are still OK, despite operating mostly from grass
>>> strips.
>>> In my opinion, the pins are very accurately made. But the holes in the
>>> TP tubes are not. My new pins were set-up so that they had to be driven
>>> in; I suspect this makes the difference. The PFA requirement is now for
>>> an "interference" fit.
>>> Duncan McF.
>>
>>
>>
>>
>>
>>
>
>
>
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