<>
You asked for it.
But I agree.
In particular, the trim motor in the Europa works hard against the high
friction load in the anti servo tab drive system; I doubt that the trim
motor would have sufficient continuous-rating to keep up with that.
Try maintaining altitude by keeping throttle position fixed and "jabbing"
manually at the trim in proportion to the magnitude of indication on the
VSI; wouldn't work on mine (due mainly to delays introduced by loose
tolerances in the trim tab system).
Duncan McF.
----- Original Message -----
From: "Jos Okhuijsen" <josok-e@ukolo.fi>
Subject: Re: Europa-List: EZ-TRIM Altitude Hold PCB
>
> Hi all,
> Just to change the key of the song song and get some relativation. Hate to
> do that, but i also feel kind of responsable if i did not say what i think
> needs to be said. Apart from not liking the idea of "soldering iron
> handicapped" fellow builders to work on flying controls with complications
> they do not grasp, there are some facts to be considered.
>
> On sun and fun i have been talking to almost every autopilot producer for
> experimentals. Both digitrack and trio do a simple attitude hold. Both use
> an extra servo. Both told me things i had not considered before. Both sell
> for a price which is a multiple of the thing we are talking about here.
> Why? Does the competition not work or?
> Imho,
> 1: The ray allen trim motor is probably just good enough for trim. I
> wonder if it has the reserves to fly the plane.
> 2: EZ-trim has had problems in the software, it is very difficult to get
> the software working without hunting or undershooting. Once there is a
> more or less stable situation, changes in the flying characteristics will
> not readjust the adjusting cycles. That was the main reason the Dutch
> abandoned the idea.
> 3: There is no insane command override other then the pilot. If, say
> because somebody opens a vent, hence pressure increase, hence correction,
> the plane ends up in a nose high attitude with 40 knots airspeed, it will
> still try to pith up.
> 4: There is no cut out on turbulence, insane commands might follow.
>
> Ok, let me have it <grin>
>
> Jos Okhuijsen
>
>
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