Linear output - was Notes to Self 3

[Jon Lowe]

Yeah, but my Dad HATES expo, doesn't even use it with 3D throws!  He is such
a smooth flyer, and uses fingers rather than thumbs,  that he doesn't need
it, He wants control response, RIGHT NOW!  So how well his breakout force
works other peoples flying is debatable.  When he was still a regular on the
pattern circuit, he did spend a lot of time playing with stick lengths and
tension. He also wouldn't use anything but open gimbol sticks because
nothing else, at the time, felt right to him.  
 
I use some expo, which drives him nuts when he flies my planes.  And my high
rates are his low rates.  I tried flying with his throws, and no expo, but
I'm not smooth enough to do it. We usually end up having different setups
for the same airplane if we are going to trade off a lot. I run my sticks up
as stiff as I can get them.  He still likes stiff springs, so at least we
share that.
 
I will say that virtually every new transmitter I pick up has the springs
set way to soft for my tastes.  It is too easy to get unintended control
inputs.  I tell budding pattern flyers (and I am one of them) to stiffen up
their springs, and everyone of them has liked the feel better.  I had a
Futaba 9C for awhile, and the stock springs at max tensions were still way
too soft, so I bought Futaba's "heavy duty" springs, and ran them up to full
stiff.  Still too soft.  If I'd kept it, I'd put on some Radio South
springs.  A lady in our club, who is trying out pattern, has a low end JR
computer radio.  The stock springs in that thing were even softer than the
9c, and couldn't be adjusted much stiffer.  She sent her transmitter off to
Radio South and got stiff springs, and she is much happier, since she isn't
getting the cross inputs. She was very frustrated before, because we could
see she was putting in some unintended inputs, but she swore she wasn't.  If
the manufacturers would stiffen up the springs from the factory, I think it
would help almost every flyer fly better.
 
Now don't tell my Dad that I questioned his tastes!  ;)
 
 
Jon Lowe
-----Original Message-----
From: discussion-request at nsrca.org [mailto:discussion-request at nsrca.org] On
Behalf Of Dean Pappas
Sent: Thursday, February 10, 2005 12:20 PM
To: discussion at nsrca.org
Subject: RE: Linear output - was Notes to Self 3


We don't adjust for "linear" throw:
Some of adjust for a linear "feel", which has to be put in quotes 'cause
nobody can define it, and because there are wild differences of opinion. 
Others simply dial enough EXPO in to get manageable sensitivities arounsd
neutral with the maximum throw that was found necessary to perform some
maneuver.
That usually means like the plane feels like it has a break-point in the
stick response, which has always driven me, personally, nuts.
 
The breakout force needed to budge the stick out of neutral is an important
part of the deal.
Jon's Dad always asserted that three ounces of breakout force were the
"correct" amount. When in doubt, listen to the Guru.
Lots of flyers dial EXPO in to solve the problem of too soft sticks, which
allow them to unconsciously put undesired inputs in.
The soft neutral reduces a problem caused by something else ... like too
darned much caffeine!
Some peoples' feel is by stick pressure, others by movement.
You'll never come up with a one-size-fits-all deal, though Don Lowe's
breakout force spec is a pretty good one.
 
Later,
Dean Pappas 
Sr. Design Engineer 
Kodeos Communications 
111 Corporate Blvd. 
South Plainfield, N.J. 07080 
(908) 222-7817 phone 
(908) 222-2392 fax 
d.pappas at kodeos.com 
-----Original Message-----
From: discussion-request at nsrca.org [mailto:discussion-request at nsrca.org]On
Behalf Of Atwood, Mark
Sent: Thursday, February 10, 2005 1:04 PM
To: NSRCA Discussion List (E-mail)
Subject: Linear output - was Notes to Self 3


Ok...I have a question for the Aeronautical engineers in the group...   All
of this discussion has been centered around an assumed desire to get a
linear relationship between our stick movement, and that of the control
surface.  Clearly the effect of moving a control surface on the aircraft is
proportional to the amount of movement...but is it linear??  I have to
beleive it's not...   Just don't know the mechanics behind it...
 
Assuming it's not...(And I'm betting for some portion of the throw is close
enough to be considered linear and then at higher deflections it becomes
either more or less efficient) is there really a purpose to trying to exact
the linear nature of the stick/control surface linkage...or it is an
exercise in retentiveness :)
 
I also know that our spring tension on the sticks in not linear...especially
around center...so it seems unlikely that what "Feels" linear isn't anyway.
 
To me it's akin to comparing two high end stereo systems both of which have
specifications well beyond the range of human hearing....
 
-Mark
 
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