The exact "V" control system puzzles me slightly. The picture in Dec. 04 MA shows
the push rods coming through the sides to get to the control horns.
The plans show the rods exiting the back where the last former gets
trimmed.
That would put the linkage and horns in the "wind shadow" of the fuselage.
As long as there will be enough control horn purchase and clearance for proper up-down, I would prefer
doing the later. Is that what you intended?
I found the note about running the push rods outside the fuse. I
guess the geometry of up and down requires that. So be
it.
From : Don Stackhouse
Well, not exactly. The problem is that the angles get a little weird.
Also, the control horns have to mount right on the inboard edges of the
ruddervators, and need some glass tape reinforcement for enough strength.
In addition, there isn't room for clevises at that end if you run them
inside, you have to rely on clevises at the servos for
adjustment.
The thing to remember is that one of the major customer types the
Chrysalis series was intended for was beginners. There are lots of things
that can be done to tweak various things. However, if we show that in the
(already frighteningly big and detailed to the point of intimidating)
instructions, we're going to encourage beginners to try things that
they're likely to mess up. We figure the experienced builders will
probably be able to figure things like that out for themselves, and in
any case they probably won't pay any attention to the instructions
anyway. Therefore, we deliberately don't cover that sort of stuff in the
instructions.
I've attached a couple photos I took just now of the tail linkage in the
plane you saw on the website photos. Yes, that's the original sailplane
prototype and it goes back to about 1997 if my memory serves. It's still
in flying condition. Its wing is shared with the electric prototype. That
wing also goes back to 1997, although recently it underwent some major
surgery to add the diagonal braces and the new spoiler linkage
arrangements. And no, it doesn't have any carbon in it. It has been
winched a few times, Hi-started a whole bunch, and even bungee launched
(30' of 3/8" rubber, 30' of cord, no parachute, gets about 100 -
150' of altitude REAL QUICK).
You can see in the photos how the control horns are arranged. In the
original version we used 42" long .032" music wire pushrods
(special ordered, had to buy so many to meet the minimum order that we
still have a few left). We switched to the braided flex cable because too
many folks were having trouble routing the music wire properly and were
ending up with too much friction.
In your case you will need to tin the flex cable for the last 2 or 3
inches, which is a good idea anyway (the extra stiffness at the ends
helps prevent control surface flutter). Tinning the flex cable will make
it stiff enough to put a Z-bend in the end. You may need to re-fit the
hole in the control horn. If it's too loose, plug it with C/A and
re-drill it.
Cut the end of the tail boom off so that there is enough clearance with
the control horn to allow for enough travel. You may need to trial fit a
little. Bring the pushrod guide tubes out through the upper holes in F5
and F6. The holes in the control horns should be in line with the tubes
so that the wire comes straight out the back of the fuselage aimed at the
hole on inboard face of the horn, with the Z-bend snaking through the
hole and out through the outboard face of the horn, as shown in the
picture.
By now it should be fairly obvious why we didn't include this in the
instructions, it probably would have taken another page or two! However,
it's not that difficult for any reasonably experienced modeler, or for a
beginner with a decent instructor.
Don Stackhouse
DJ Aerotech
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