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The following question came from Jim


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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