elevator pushrod exits

[Troy A. Newman]

The exits will depend on you servo and elevator control horn locations.
These need to be mounted first.

Next locate the servo arm connection point and transpose this to the side of
the fuse on the outside. We are going to project two lines down the fuse
with a  long 3 or 4 ft straight edge.  Looking at the side of the fuse use
the straight edge to connect the mark on the side of the side up at the
forward servo connection and the top of the elevator control surface horn.
I use masking tape on the side of the fuse near where I think everything
will exit. I then draw a line on the masking tape along the straight edge. I
use a pencil-sharpie(thin)-or a ball point doesn't really matter.

Next step is to transpose the mark on the side of the fuse to the bottom of
the fuse.. Place the model inverted on the table or in a  stand...Apply a
length of masking tape vertical to the fuse and wrap it around the fuse past
the bottom seam or center location. Note if your servo connection point is
not centered in the fuse you'll have to offset this belly starting point for
the next projected line. My elevator connections are always in the
center...So my 2nd projected line starts at the fuse seam. or in the middle.
If your servo connection location is 1" off to one side then you need to
make a mark on the masking tape in this location...This is projecting down
thru the fuse..you are just transfer this location to the tape.

Now use your 4ft straight edge again and this time go from the forward mark
on the belly out directly toward the control horns. Looking down from above
put a mark on the side of fuse (on your masking tape that was done in the
previous line projection down the side.) Where these two projected lines
cross....This is your fuse exit location.  Depending on you fuse width,
control horn spacing from centerline, and distances to the front
servo...this slot is usually about 1.5 to 2" long. You will have to work the
slot with a small round file to get the inside angles to prevent bending of
the tubes as they exit..

Trial fit the whole thing into place and use the round file to open the fuse
up in order to eliminate bending of the tube guides as they exit. This is
what causes friction in the system. Also make sure that you have no friction
when the rods are in the tubes, tubes attached to the balsa sticks, and the
system is not in the model. All you want is to duplicate this non-friction
condition by not having the tubes bending as they exit the fuse.

Its an easy thing once you try it. For reference my exits on my (2) Supremes
are about 10inches in front of the elevator control horn locations. Yes 10
inches of this 0.070" pushrod is un-supported. It is still stiffer and more
solid than any other system I have seen or used. Depending on how wide your
fuse is, where your elevator servo is located, how long the fuse is, and how
far from the centerline your elevator control horns are will determine the
exit locations.

On a fuse that is not painted or finished its cake...Make the slots bigger
and allow the system to float. Then fill the excess gaps with some
lightweight filler. If the fuse is wood and monokote-Ultraote and unfinished
its easy a small sliver of balsa can be your filler. If its already covering
with iron on covering then you can patch a mistake.

 If the model is done and painted...you have to be careful. I have done 3
models recently that were finished painted and done. The exit slots can
still be done clean and neat.

Good Luck, Its not that hard to figure out.

Troy

----- Original Message ----- 
From: <tph1 at bellsouth.net>
To: <discussion at nsrca.org>
Sent: Monday, December 06, 2004 8:51 AM
Subject: elevator pushrod exits


> I'm trying to figure out a way to get my Dual elevator push rod system to
be installed correctly. How can I determine where the exit hole/slot will be
in the fuse for this? I don't want to leave a 4" slot in the fuse as an
Oop's either.
> thanks
>
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