Some people have questioned the use of a bent control
tube and the long control tube from the aft spar to the
walking beam in the elevator control system.  I conducted
this test to determine if the tubes is strong enough to use in
the elevator control system.

First I used some scrap metal to
secure rhe elevator horn. This horn
was made for a cable systen so the
upper part of the horn is not used with
the control tube systen and made a
handy way to secure the elevator  for
this test.

I welded a bolt to a piece of angle
metal then clamped it to the control
stick horn near where the bent tube is
attached.

With the bolt clamped in place I used a
torque wrench to measure the force
applied to the control system

The camera was placed in a corner so
I could take multiple pictures with  the
same angles. This is the bent tube with
no force applied.

Compare this picture with the one
above. This is with 50 foot pounds
applies in an elevator up direction.
There is some slight flexing of the tube.

The scale on the torque wrench is not
readable in this picture but I'm applying
50 foot pounds of force to the control
system

The picture above is the long tube with
no force applied. Below is 50 foot
pounds applied in a up direction. I
could see no flexing in this tube.

This is with 50 foot pounds applied in
elevator down direction. Again some
slight flexing.

I am satisfied that my system is good
enough for KR work. If I ever need 50
foot pounds of force to operate the
elevator I'm already in big trouble.
Even with the flexing of the tube I am
still confident in my system.