fuse leveling
Posted: Fri Feb 17, 2012 5:46 pm
To whoever asked or will ask about leveiling the fuse for setting the
stab incidence,
I asked the same question and received this from Murphy tech
support on 3/27/2000,
"The angle of incidence for the rear horizontal stab is set relative to
true
level with the tail elevated to the flight level attitude of the
aircraft.
This is the attitude the aircraft should be in when it is leveled using
the
belly for a reference. However the alternate would be to use the
vertical
fin main spar as a reference in your case, this should be in the
vertical 90
degree position at flight attitude. Regardless of the rest of your
measurements if you set your stab while the fuselage is positioned to
achieve the 90 degree vertical angle on the vertical fin you will have
the
reference point you need for setting your horizontal stab. This is still
11/32 over a 20" distance.
Grant
Tech Support."
The only problem I found with this is that I found my vertical fin to be
canted forward by about 1/4 " at the top(Mooney style).
There is an autocad drawing (by Murphy) of the fuselage that when you
pick dimensions off of it you find that the center crease of FUS-22-1 is
level with the thrust line which would be level with the table (19" from
table to thrust line). The center crease is 2.125" higher than the
thrust line. This panel has been fairly accurately positioned when the
skin is laid out on the table, thereby providing a stable and accurate
measuring line. Another good reference dimension is one that goes from
the thrust line to the bolt centerline of the rear stab mounting tab, it
is 6 1/8". This dim may vary from aircraft to aircraft.
The way that I set the stabs prependicular to the table was to center
the A/C on the table and set up a straight edge(9' long) perpendicular
to the centerline. With the rear stab bolt in the rear hole and the stab
propped up in approximate position, I dropped a plumb bob down from the
rear of the elevator hinge brackets until I got the same dimension from
the rear (inner and outer) of the elevator hinges.
I hope this helps.
Good luck.
Rick D.
REBEL S/N 446
Murphy says the O-235 and O-320 thrust lines are the same only with the
firewall moved back 3" for the O-320.
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stab incidence,
I asked the same question and received this from Murphy tech
support on 3/27/2000,
"The angle of incidence for the rear horizontal stab is set relative to
true
level with the tail elevated to the flight level attitude of the
aircraft.
This is the attitude the aircraft should be in when it is leveled using
the
belly for a reference. However the alternate would be to use the
vertical
fin main spar as a reference in your case, this should be in the
vertical 90
degree position at flight attitude. Regardless of the rest of your
measurements if you set your stab while the fuselage is positioned to
achieve the 90 degree vertical angle on the vertical fin you will have
the
reference point you need for setting your horizontal stab. This is still
11/32 over a 20" distance.
Grant
Tech Support."
The only problem I found with this is that I found my vertical fin to be
canted forward by about 1/4 " at the top(Mooney style).
There is an autocad drawing (by Murphy) of the fuselage that when you
pick dimensions off of it you find that the center crease of FUS-22-1 is
level with the thrust line which would be level with the table (19" from
table to thrust line). The center crease is 2.125" higher than the
thrust line. This panel has been fairly accurately positioned when the
skin is laid out on the table, thereby providing a stable and accurate
measuring line. Another good reference dimension is one that goes from
the thrust line to the bolt centerline of the rear stab mounting tab, it
is 6 1/8". This dim may vary from aircraft to aircraft.
The way that I set the stabs prependicular to the table was to center
the A/C on the table and set up a straight edge(9' long) perpendicular
to the centerline. With the rear stab bolt in the rear hole and the stab
propped up in approximate position, I dropped a plumb bob down from the
rear of the elevator hinge brackets until I got the same dimension from
the rear (inner and outer) of the elevator hinges.
I hope this helps.
Good luck.
Rick D.
REBEL S/N 446
Murphy says the O-235 and O-320 thrust lines are the same only with the
firewall moved back 3" for the O-320.
*-----------------------------------------------------------------------------------*
The Murphy Rebel Builders List is for the discussion
between builders and owners of Murphy Rebel aircraft.
Archives located at:
http://www.dcsol.com/murphy-rebel/lists/default.htm
*-----------------------------------------------------------------------------------*
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