Mark,
I had a similar head room issue with my standard KR-2. I made a new
fiberglass seat bottom one inch thick and clears the fuselage bottom by
3/8". To clear the elevator control link, I cut a channel in the middle of
the seat pan and closed this cutout top with 0.030" aluminum sheet secured
with CS flathead screws and T-nuts on the bottom. The control link is a
Bowden-type cable. This is a heavy duty Seastar Xtreme 40C series control
cable for outboard motors. Rating is 500 lb. push or pull. Uses 1/4-28
threads each end for link attachment. The 40C Xtreme series has a splined
inner sheath for minimum slop and smooth, easy movement (not cheap). Total
diameter is 5/8" not counting end hardware. Comes in 1-foot increments from
2-ft. to 56-ft. You have to order this through a marine supply dealer.
Like any Bowden cable the ends of the outer sheath must be firmly anchored;
I used C clips (from Seastar) through bolted to the fuselage bottom with CS
flathead 10-32 screws and Nylon stop nuts. I needed 23" end to end; so got
the 2-ft. unit. Generous thread length on the shaft ends gave plenty of
adjustment room.
Were I to do this again, I would run the (Seastar) elevator control cable
one-piece from bottom of stick to the upper elevator horn. No need for
reversing bell cranks for push rods, no cables or pulleys. The vertical
stabilizer forward spar would provide an excellent outer sheath anchor
point. My vague recollection is the Lancair 320 used a similar control
linkage for both elevator and rudder. Perhaps the aileron links on
Wunderbird could use this Seastar type control; go direct without pulleys or
bell cranks.
Sid Wood
Tri-gear KR-2 N6242
California, MD, USA
----------------------------------------------------------------------------------
Well I just came across my first major setback on this build. I sat in the
cockpit with the canopy on today and guess what...I don?t fit. My head is
slightly tilted and hits the canopy. WTF. I sure thought I had this all
measured out correctly. Must have been the root beer. The only remedy is to
lower the seat. This is going to require using a pushrod from the control
stick to a bell crank behind the rear spar and rerouting of the aileron
cables. Then I will reconstruct the seat bottom to allow my bottom to be
about one inch above the floor. Doing all this will give me the headroom I
need.
Mark Jones
Oldsmar, Fl
N771MJ ?WunderBird?
www.flykr2s.com
flyk...@gmail.com
_______________________________________________
Search the KRnet Archives at https://www.mail-archive.com/krnet@list.krnet.org/.
Please see LIST RULES and KRnet info at http://www.krnet.org/info.html.
see http://list.krnet.org/mailman/listinfo/krnet_list.krnet.org to change
options.
To UNsubscribe from KRnet, send a message to krnet-le...@list.krnet.org
