Control horns, is it just me or... ?

[Keith Black]

That looks quite interesting. I do have a couple of concerns however.

Given that the mounting plate (foot) is perpendicular to the arm when the
arm is mounted on a control surface with an air foil shape the arm will
actually be pointing backwards away from the hinge line. To avoid this one
would either need to prop up the back side of the mounting plate or recess
the front of the plate down into the control surface. With this particular
design it seems that you'd have to cut pretty deeply into the control
surface on the leading edge to get the arm to be perpendicular to the hinge
line.

Second concern is that the arm is not located on the edge of the mounting
plate, which means that it would be moved back a bit from the bevel thus
offsetting the advantage of the longer arm.

I promise I'm not trying to be difficult ;-)

Keith Black

----- Original Message ----- 
From: "Michael Ramsey" <michaelr at flying-models.com>
To: <discussion at nsrca.org>
Sent: Wednesday, September 03, 2003 11:07 AM
Subject: Re: Control horns, is it just me or... ?


> http://www.radioactivemfg.com/horns.htm
>
>
> ----- Original Message -----
> From: "Keith Black" <tkeithb at comcast.net>
> To: <discussion at nsrca.org>
> Sent: Wednesday, September 03, 2003 11:40 AM
> Subject: Re: Control horns, is it just me or... ?
>
>
> > Tom,
> >
> > You make a good point about the ZNLine horns not being adjustable in
> height.
> >
> > Honestly, if I could just find some longer arms to go on the IM horns
that
> > would solve the problem. It's surprising to me how many manufactures
have
> > not considered this, especially since pull-pull has been such a big deal
> for
> > a while now.
> >
> > One reason I'm being picky about this is that on this plane I was
> > considering using pull-pull on the elevator and rudder. That means three
> > different surfaces (two elevator halves and the rudder) need the
> connection
> > point over the hinge. This also rules out angling the horn arm since the
> > opposite side would stick out the wrong direction. Since, I'll be doing
> this
> > on three surfaces I'd prefer to use a product that's designed to do the
> job
> > rather than trying to make something work that wasn't designed to solve
> the
> > problem.
> >
> > Thanks for you input, you made some good points.
> >
> > Keith Black
> >
> >
> > ----- Original Message -----
> > From: "Koenig, Tom" <Tom.Koenig at actewagl.com.au>
> > To: <discussion at nsrca.org>
> > Sent: Tuesday, September 02, 2003 10:33 PM
> > Subject: RE: Control horns, is it just me or... ?
> >
> >
> > >
> > > Keith,
> > > Try a smaller bevel...but do both sides of the hinge line.
> > >
> > > I do it much like Gerald. I use 3 mm stainless steel rod however for
my
> > > horns. I make sure the threads are rolled threads and not cut. I bevel
> > both
> > > sides of the hinge line, and then I spend a little time on the lathe
and
> > > make up a little 'cone' style rod supports, much like what you now see
> on
> > > the IM hardware.
> > >
> > > I prefer the threaded rod style 'horns'. The fine metric thread can
give
> > you
> > > very precise adjustments when setting up a model. I do it all
> mechanically
> > > first. I find then that the 'electronic' adjustment is only a few
> percent
> > > either way. Sometimes I 'turn' my threaded rod by only a 1/4 of a turn
> to
> > > get the exact throw I'm after, then I'll glue and lock it down.
> > > Infact I have found great variations in accuracy in the actual servos
> this
> > > way.
> > >
> > > I guess thats one advantage some sponsored flyers have..they can go
> > through
> > > a pile of servos to "match" them as close as possible to each other.
> > >
> > > I too have used the ZN, PL horns....but they limit you to the height
of
> > the
> > > horn. There is only one place to mount your clevis. I find I cannot
get
> > the
> > > mechanical adjustment I require from this style of horn...but they
sure
> > look
> > > nice! Impractical in my book however. I just cannot maximise the
> > resolution
> > > of my radio using this style of horn.
> > >
> > > There are some plastic arms out there that measure 8mm from centerline
> to
> > > the pivot hole. I buy them from our local shop...BUT...they only come
as
> > > part of  an aileron torque rod set up. I believe they are a British
> brand.
> > > The make is RADIOACTIVE. I really cant help you much more than that. I
> am
> > > unaware of a website for them ( I have not looked yet!). I just use
the
> > > arms. The torque rods end up getting twisted into "art" <BG> by my
three
> > > year old!
> > >
> > > If you get really stuck, I''ll ask what I can at our local shop.
Failing
> > > that , I can try and send some to you if  you are desperate. Just
> remember
> > > I'm down here in the land of Aussies, so it too is a long way!
> > >
> > > Good luck and zap me offline if you need any further help.
> > >
> > > Tom
> > >
> > >
> > >
> > > > ----------
> > > > From: Keith Black[SMTP:tkeithb at comcast.net]
> > > > Reply To: discussion at nsrca.org
> > > > Sent: Wednesday, 3 September 2003 13:49
> > > > To: discussion at nsrca.org
> > > > Subject: Re: Control horns, is it just me or... ?
> > > >
> > > > Gerald, thanks for the reply, your description was quite clear.
> > > >
> > > > How do you deal with the pull-pull horns for the rudder (especially
> > > > considering that the rudder has a larger bevel to allow larger
> > > > deflection)?
> > > >
> > > > Thanks,
> > > > Keith
> > > >
> > > >
> > > > ----- Original Message -----
> > > > From: GW
> > > > To: discussion at nsrca.org
> > > > Sent: Tuesday, September 02, 2003 9:31 PM
> > > > Subject: Re: Control horns, is it just me or... ?
> > > >
> > > > What I do on ailerons and elev.
> > > >
> > > > Install 1/2" dowel in surface. starting roughly 1/8" from LE bevel.
> > > > Set up drill press plate for a 10 degree table tilt.
> > > > Tape moveable surface into the aileron(elev) cutout shuck (bottom of
> > > > surface up) WIth it in its shuck and the 10 degree angle on the
Press,
> > > > drill 1/8 hole through the Dowel starting at about the top of the
> > beveled
> > > > surface . This will put the exit near the rear of the dowel on the
top
> > of
> > > > surface, but it does not matter. Shoot a 6/32 hardened bolt though
the
> > > > dowel, It will be tight, but thats what were looking for, let it tap
> its
> > > > own threads as your run it in. Go about 3/4 the way into the surface
> and
> > > > stop. cutoff the excess with the cutoff wheel.
> > > > Attach your favorite aileron connector and clevis now, and you will
> > > > be very close to the hingeline.
> > > >
> > > > Or you can do as a majority do, and dont worry about it. Youcan use
> > > > your CRC meter to get the deflections the same. Our really neat
> computer
> > > > radios have taken alot of the need to build perfect out of the
> equation.
> > > > I like to do it right myself, but thats just me.
> > > >
> > > > This is just one way to do it with minimal trouble, and less
> > > > expense. Im sure others will have a better approach that works for
> them.
> > > >
> > > > I can draw CorelDraw or ACAD file that would illustrate this better
> > > > if anyone has an interest.
> > > >
> > > >
> > > >
> > > > GW
> > > > Gerald Williams
> > > > Email : gw at gwair.com
> > > > Webpage: www.gwair.com
> > > >
> > > > Support Tony Stillman District 5 VP
> > > > http://webpages.charter.net/nneville/nneville/
> > > >
> > > >
> > > >
> > > >
> > > > ----- Original Message -----
> > > > From: Keith Black
> > > > To: discussion at nsrca.org
> > > > Sent: Tuesday, September 02, 2003 8:57 PM
> > > > Subject: Control horns, is it just me or... ?
> > > >
> > > > When it comes to control horns for pattern planes it seems
> > > > to me that some of the most commonly used choices have a major flaw.
> > > >
> > > > On my last plane I used the MK Aluminum Horns on all
> > > > surfaces except for the rudder where I used the IM pull-pull horns.
> Both
> > > > of these are nice horns except they have a major flaw when using a
> > > > pull-pull setup. The flaw is that the little black plastic arm that
> > screws
> > > > onto the horn and connects to the clevis is so short that it doesn't
> > > > extend out over the hinge line. I know that with pull-pull systems
it
> > > > isn't *absolutely* necessary for the connection to be exactly above
> the
> > > > hinge, but the further back it is the more slack there will be in
the
> > > > cable that is not pulling.  In my opinion with these horns the
> > connection
> > > > point is too far away from the hinge unless the horn is virtually
> > mounted
> > > > on the control surface bevel (especially when it comes to rudder).
> This
> > > > can easily be seen in these "instructions" for installing the MK
horns
> > > > http://www.centralhobbies.com/buildingtips/mkhorns/mkhornsinst.html.
> > > > Notice that in this picture there surface isn't beveled yet and the
> horn
> > > > is almost on the edge.
> > > >
> > > > On my new plane I wanted to avoid this problem so I did some
> > > > searching to find a better solution. To begin with I looked for a
> longer
> > > > arm to connect to the MK horn, one that would extend out to the
hinge
> > > > line. I found two options from Sullivan but both require too big of
a
> > horn
> > > > thread (6-32 and 8-32). My search then led me to two other choices
> that
> > > > seem to be good alternatives. The first is the ZNLine aluminum
control
> > > > horns, but these are apparently only distributed by ZNLine (
> > > >
> >
http://www.znline.com/produits.php?langue=english&cle_menus=1025879382&cle
> > > > _data=1025901639) which means an international order. The other
> solution
> > > > I've found is by RC Model Enterprises (
> > > > http://home.att.net/~rc-enterprises/rcme_014.htm) but these control
> > horns
> > > > seem very pricey!
> > > >
> > > > If anyone could point me to a longer 3mm connecting arm that
> > > > will fit on the MK and IM horns I'd be happy (BTW, I've used the MK
BB
> > > > connectors on the MK horn and they still aren't really long enough).
> > > >
> > > > Is it just me, or have others experienced this dilemma as
> > > > well?
> > > >
> > > > Thanks,
> > > > Keith Black
> > > >
> > > >
> > > >
> > >
> > >
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