CTE

[Wayne Galligan]

When I flew my first true late model pattern plane I was using a Futaba
6XAS.  After realizing that these modern day flyers truly do fly better and
with so much more precision I found it very difficult to get the slide trims
to center or trim true.  A switch to the 8UA and major difference.... and I
though the 6XAS would do everything I needed... and it does for the money.
But the digital trims where so much sweeter and you don't have to worry
about bumping the trim slider when handling the transmitter.  On the 8UA(and
I am sure on most other top end transmitters) you can adjust, fine or
course, the amount of trim with each bump of the trim tab.


Wayne G.
----- Original Message ----- 
From: "Jeff Hughes" <jhughes at hsonline.net>
To: <discussion at nsrca.org>; <discussion at nsrca.org>
Sent: Monday, December 01, 2003 2:01 PM
Subject: Re: CTE


> Easy enough to check. Tonight I'll measure one click on a typical
> futaba set up. (I know it will also depends on arm orientation (servo
> motion is rotational converted to linear) and arm length). But at
> least it will be a ball park.
>
>
> > That would depend on if you had a low cost Futaba(w/slide trim) vs.
> a high
> > end JR(w/digital trims)
> >
> > Wayne G.
> >
> > ----- Original Message ----- 
> > From: "george kennie" <geobet at gis.net>
> > To: <discussion at nsrca.org>
> > Sent: Monday, December 01, 2003 1:11 PM
> > Subject: Re: CTE
> >
> >
> > > If a digital servo moves one increment of it's total resolution
> with each
> > > click of the trim lever, then .013 is equal to about 39 clicks of
> your
> > > trim. Maybe enough to do a big loop?
> > > Probably no where near the realityof the actual, but I'll still
> bet there
> > > are a lot of clicks involved to move your elevator .013 ( I'm
> betting more
> > > than 10 and probably close to 20). I'm assuming, of course, that
> you have
> > > your trim rate adjusted to it's smallest value.
> > > G.
> > >
> > > Jeff Hughes wrote:
> > >
> > > > I stayed out of this thread earlier. But if you run the numbers
> for a
> > > > 50 degree temp swing, your only talking 0.013" of differential. I
> > > > doubt if someone is noticing that. Probably the horsepower
> difference
> > > > over a 50 degree swing makes more difference in how the plane is
> > > > flying.
> > > >
> > > > > Nat
> > > > >
> > > > > I was gone last week....The CTE for balsa will change with the
> > > > density of
> > > > > the balsa it self, but as you have noted, humidity plays a
> larger
> > > > part
> > > > > here in expansion and contraction. This is not a factor with
> the
> > > > composite
> > > > > pushrods.
> > > > >
> > > > > I am not as inclined as Jason was to read all those emails
> while I
> > > > was
> > > > > gone, but in short CTE is not so much a problem as is the mis
> > > > matched CTE,
> > > > > in this case the carbon fiber pushrod vs. the fiberglass
> fuselage. I
> > > > have
> > > > > not run the calculations but anyone interested assume the CF
> rod to
> > > > have a
> > > > > CTE of zero, then the fuselage to have a CTE of 6.5 X 10-6
> in/in F.
> > > > I
> > > > > would imagine that if you set your trim at 100F then flew in
> > > > December at
> > > > > 50F you may have one or two clicks of trim to compensate.  The
> > > > original
> > > > > post asked about storage down to zero F. In reality the servo
> arm or
> > > > > elevator would just move with the cold contraction.
> > > > >
> > > > >
> > > > >
> > > > > Gray Fowler
> > > > > Principal Chemical Engineer
> > > > > Composites Engineering
> > > > >
> > > > >
> > > > >
> > > > >
> > > > > "Nat Penton" <natpenton at centurytel.net>
> > > > > Sent by: discussion-request at nsrca.org
> > > > > 11/24/2003 09:24 PM
> > > > > Please respond to discussion
> > > > >
> > > > >
> > > > >         To:     <discussion at nsrca.org>
> > > > >         cc:
> > > > >         Subject:        CTE
> > > > >
> > > > >
> > > > > Gray what is the CTI for balsa ? I have carbon push rods /
> balsa
> > > > fuse and
> > > > > my elev trim moves around considerably. I suppose it is
> because of
> > > > > humidity variation between the shop and outdoors ?? The
> pushrods are
> > > > 50"
> > > > > long.      NatPenton
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > >
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> > > > CoreComm Webmail.
> > > > http://home.core.com
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