Frank Hamelly wrote:

> I want to use a split elevator on my KR and am wondering how to
> attach the two halves in the middle to maintain structural integrity.
> I've seen that Steve Anderson's KR used a split elevator but how were
> the two sides fused?

Steve's are joined something like the enclosed sketch (although maybe it 
has two bolts), using some thicker spar material (maybe an inch tall) 
and 1/8" aluminum plates front and back.  I thought about doing 
something similar to mine when I was building it, but with 20/20 
hindsight, it would have been a waste of time and weight.  I used simple 
Oilite (bronze impregnated bushings) hinge bushings in the plans 
aluminum brackets, and they are still slop free after 1130 hours.  I put 
the access slots on the bottom of the horizontal stab (or elevator, I 
forget which) so that the slot was only exposed when the elevator was 
fully deflected.  This way it didn't affect flow at the joint.  More on 
that at http://www.n56ml.com/kht.html .

> Also, thinking about using gap seals between the horizontal and
> vertical stabs and the elevator/rudder. I have a 7/8" gap to fill
> which seems like it would be much easier to use than building up the
> bull nose on the leading edges while providing clear access to the
> hinges. I'm using the rod-end bearing hinge design, with 5 hinges
> instead of 3.

You've probably seen how I did the bull-nosed thing (at 
http://www.n56ml.com/kvs.html ), but what I didn't show is how I deleted 
the cutouts for accessing the connecting bolts, because I deleted the 
connecting bolts entirely by using a 3/16" 4130 tube to join the rudder 
to the vertical stab.  It dropped in from above and got the top two 
hinges, and then another short one was inserted from below.  Both had a 
little 4130 tab welded on the end for a #6 wood screw to hold the pins 
in place, although the bottom one was captured by the tailspring and the 
top one had gravity working for it. The 4130 tube was a lot lighter than 
the three bolts and nuts would have been, and it was dirt simple to get 
the elecvator off....but again, there was no slop after 1130 hours 
anyway, using only three hinges.  And I use my rudder a lot...

Mark Langford
ML at N56ML.com
http://www.n56ml.com

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