I have a Stick type model with rear mounted elev and rudder servos using 9" long 4-40 size wire pushrods which I would like to stiffen up a bit and would like some suggestions on how to accomplish that without adding too much weight to the tail.

Karol

You could just lay another piece of wire nest to it about 6 or 7 inches long, wrap the ends and middle with copper wire and solder it on.

Or, you could do the smae thing with a piece of dowel, wrap with thread and glue instead of solder

If the wire passes near bulkheads, glue in some supports. Heck, if it's just near anything wood, glue in supports.

Almost no weight added and you get the same result.

You can cut short pieces of pushrod tubing (which is made for this job) and slip 'em on the rod. Slide 'em to where the bulkheads (whatever) are and glue scrap balsa to fit. Bingo.......

Two or three are enough for fuselage length rods.

Can't reach down inside the fuselage? Are there lightening holes in the fuselage bottom/sides? They're perfect semi-perminent hatches. Cut out the covering and worth through the hole/hatch. Iron on a patch of the same color covering after the brace is in place.

My Stiks have all been GP's. I did stiffen the rods on one of the ARF variety by fishing a strip of lite ply back across the cutout in the center of one the rear bulkheads, under the pushrods. Then, I notched out another strip to accept each of the pushrods, guestimating the amount of separation (I was a little off, but not enough to matter enough to notice). Again I fished the ply back to the same bulkhead over the pushrods, trapping them against the first piece. To do the fishing, I drilled a small hole in the center of each strip of ply and screwed in a threaded wire pushrod making a long handle. I applied 5-minute epoxy to each end of the strip, fished it to the bulkhead and, when I got it positioned, pushed on my "handle" to set it in place. It took a little maneuvering to get the strips past the servo tray, but after a couple of dry (no epoxy) runs, I found the right path. The only real problem I encountered was having to sit there holding the strips in place until the epoxy set up enough to be able to unscrew the handle. Sounds more complicated than it actually is.

BTW, last time I wanted to stop pushrod bending, I didn't bother with pieces of tubing. A piece long enough to reach from the exit hole in the rear of the fuse almost to the rudder servo worked great.

Pulled the clevis off at the rudder end, and ran the tubing into the exit hole over the pushrod to about 3-4" from the servo arm. Put a brace on the tubing right inside the fuse at the servo end. Used a semi-hatch halfway to the tail to put in a 2nd brace. Pulled the wire then so I could glue the tubing at the exit hole. After the CA set, the protruding stuff was razored flat to the fuselage side. 3 supports and a professional looking job that took maybe 15 minutes.

karolh,

Not sure how your setup is but if the 4-40 rod is all exposed I would buy some 4-40 all thread rod and some Mid West Carbon Fiber tubes and slide it over the 4-40 rods and lock it in place with 4-40 nuts on each end. Done this many times on big gassers.

That's a tip I'll remember. Thanks; Ernie P.

I have done something like this but with small CF arrow shafts with some epoxy. Brass tubes and solder.

Thanks to all who responded, but I do like the simplicity of Zippy's arrangement and since mine is of a very similar nature I plan on stiffening my pushrods as he did his.

Karol