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Re: Europa-List: Autopilot servo instalation

Subject: Re: Europa-List: Autopilot servo instalation
From: nigel_graham@m-tecque.co.uk <nigelgraham@mtecque.co.uk>
Date: Tue, 14 Apr 2015 14:57:08
I can see no reason why a composite bracket could not work provided it 
was well made. I would suggest two "question mark" (?) shaped mouldings 
back to back to ensure that the laminates are continuous (i.e. don't 
bond a flat piece onto a curved piece). My first choice though, would be 
tig welded steel.

With regards to aileron servo, I did fabricate a 2024 alloy bracket 
which was bonded and countersunk-screwed into the flat back-face of the 
P1 control yoke (prior to assembly of the control system) and driven by 
the sevo sitting under the seat via short pushrod in front of the seat.

If you have already constructed the under-seat controls, then your 
options are limited.

Nigel


On 14/04/2015 13:06, William Daniell wrote:
> Nigel
> perfect thanks.
> Thank makes life a lot easier that than changing the cross ways 
> control tube.
> Do you see any reason why the bracket would have to be steel...for 
> example could it be composite provided that it was sufficiently 
> strong/well made?
>
> Is there a similar option for the aileron servo - ie one that doesn't 
> require the bracket on the torque tube?  Perhaps attached to the base 
> of the joystick.
> Thanks again
> Will
>
> William Daniell
> LONGPORT
> +57 310 295 0744
>
> On Tue, Apr 14, 2015 at 2:11 AM, nigel_graham@m-tecque.co.uk 
> <mailto:nigel_graham@m-tecque.co.uk> <nigel_graham@m-tecque.co.uk 
> <mailto:nigel_graham@m-tecque.co.uk>> wrote:
>
>     Bud, Will, I have attached a couple of drawings and a picture of
>     the UK mod application for the scheme that Bud described FYI
>
>     Nigel
>
>
>     On 13/04/2015 20:39, Bud Yerly wrote:
>>     Yep.  Bob Berube first showed me and it is simple.  I use 2 in
>>     tube cut in half with a drove lug or post welded on for MW-4
>>     attached.  Put 3/32 silicone cowl seal in the tube and clamp it
>>     on.  I prefer this if there is no access in the aft end.
>>
>>     Bud
>>
>>     /Sent from my Verizon Wireless 4G LTE DROID/
>>     On Apr 12, 2015 10:18 PM, William Daniell
>>     <wdaniell.longport@gmail.com>
>>     <mailto:wdaniell.longport@gmail.com> wrote:
>>     Bud
>>     Does this mean that you put a clamp on the main torque tube?
>>     Will
>>
>>
>>     William Daniell
>>     LONGPORT
>>     +57 310 295 0744
>>
>>     On Sun, Apr 12, 2015 at 9:02 PM, Bud Yerly <budyerly@msn.com
>>     <mailto:budyerly@msn.com>> wrote:
>>
>>         Alan,
>>         Nice clean job.
>>         I prefer not to run a thin wall one inch tube that far
>>         without an idler in the center.  However, the pitch system
>>         only needs a couple of pounds of pressure when out of trim,
>>         and when the stab is trimmed neutral, very little pressure is
>>         necessary to move the stab. We design our systems for the
>>         worse case scenario, that is, full trim up the the max torque
>>         of the trim motor and the bending moment of the thin wall
>>         tubing has to be capable of taking the load plus a rather
>>         large safety factor (since it is a control system) without
>>         bending or flexing.  If the trim tube should bend, it can
>>         jamb the flight control.
>>         I prefer to put the trim motor where you did, but make a 3/2
>>         ratio arm to drive the tube via a tube clamp.
>>         However, to keep a short drive tube, I would recommend
>>         installing the new light weight servos behind the mass
>>         balance post using a two inch extension from the torque tube
>>         arm (there are two holes there anyway to mount .016 steel
>>         arms to).  Use a 1/2 inch with .049 wall for the drive tube
>>         (like the aileron tubes).  The length of the tube should be
>>         about 2 feet.
>>         Regards,
>>         Bud Yerly
>>         *From:* Alain Chabert <mailto:alainchabert@wanadoo.fr>
>>         *Sent:* Saturday, April 11, 2015 1:05 PM
>>         *To:* europa-list@matronics.com
>>         <mailto:europa-list@matronics.com>
>>         *Subject:* Re: Europa-List: Autopilot servo instalation
>>         Hello,
>>         Look at the solution I adopted from 330 hours and is much
>>         simpler than the proposed mod.
>>         Regards
>>
>>         *Alain CHABERT*
>>
>>
>>         __
>>         Le 11/04/2015 18:44, William Daniell a crit :
>>>         I have seen searching through the list that there are some
>>>         alternatives to the major surgery required for Mod 75 and 76.
>>>         For example I saw some correspondence between Raimo and Bob
>>>         Gowing connecting servo to the tail plane torque tube using
>>>         a bracket.  I assume that the service is mounted on a
>>>         fiberglass bracket mounted on the floor ....
>>>         Could I prevail on anyone who has who has an alternative to
>>>         the official mods and which does not require major surgery
>>>         send me a pic please.
>>>         Many thanks
>>>         Will
>>>         William Daniell
>>>         LONGPORT
>>>         +57 310 295 0744
>>>         *
>>>
>>>
>>>         *
>>
>>         *
>>
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