Paul, I measured the longerons on the Legacy. They come out to
9.25" below
the top of the cowl or 1.125" below the top hardpoints. The
drawing shows
the thrust line to be 1.5" below the longeron line, then angles
down 1
degree and to the right 2 degrees.
Bill Bradburry
Paul, I was incorrect when I indicated above that the drawing shows
the
thrust line to be 1.5" below the longeron line. Another look at the
drawing shows it to be 2.5" instead.
Bill Bradburry
Can you take a direct side shot of the existing motor mount?
Also Jerry could measure the current existing mount when he gets it
and determine the thrust line from those measurements since
he has dwg's on Lycoming dynafocal mounts.
Paul Lamar ...No rotor no motor.
I only have the pics that I sent. The mount is not here now so I can
not
take more pics. I will send the mount to Jerry when we are ready to
start
the modification.
Bill Bradburry
OK No problem Bill. Jerry can used these dwg to figure out
exactly where the thrust line is from the old mount
--------------------------------------------------------------- From
this overlay the engine looks higher and not lower.
Not to worry Bill we will figure it out exactly when we get the old
mount.
Paul Lamar ...No rotor no motor.
Paul and Bill, I am not worried about determining the thrust line
once I have the MM. I am concerned that the strut may be affected by
the height of the engine in some way we did not anticipate. Using
Rhino and the proper thrust line NOW at this phase of the design is
extremely important in my view so that we know how it will turn out
before starting.
Jerry
I can't get it any closer than this without knowing the exact
position.
When are you getting the motor mount? If we must fit it in the cowl we
should also have the cowl.
Paul Lamar
Paul, Take the picture of the Legacy in this overlay, and combine
the thrust
line you now have, with the thrust line shown in the drawing that
Jerry has
showing the thrust line of the Dynafocal mount. I expect that the
thrust
lines will line up exactly. (at least within the error of my
measurement
:>) )
Try it, you will like it!
Bill
Good idea. I'll try the dynofocal drawings in a bit.
The problem with the last overlay front view pic is it was taken
looking
down on the mount. Also the camera was a bit too close to the mount so
you get distortion from that source as well. It works best when you
are far away from the object you are trying to measure.
The side view was much better because it used this jpg where
the camera was well away from the motor mount..
This is a very powerful technique that I discovered just recently
built into Rhino.
I also used the drawing as a back ground to Check on the dimensions of
the firwall hard pounts.
Paul Lamar ...No rotor no motor.
Is this what you had in mind Bill?
Paul Lamar ...No rotor no motor.
Yes, You may now need to overlay the Legacy picture with Jerrys
drawing to
see if my measured thrust line will line up with the thrust line of
his
Dynafocal drawing. If it does, we have the correct measurements and
can
design to our hearts content. Then all we have to do is make it
like the
drawing...:>)
Bill
Ah so that is not possible because they are both jpg's.
We don't have a real drawing of a Lyc dynafocal mount yet.
All we have is a jpg of the drawing. Of course I could make
one in Rhino. Might be handy.
Paul Lamar ...No rotor no motor.
Paul, attached is 3 view DXF of the dynofocal engine mount. It is in
autocad. You may have to mess with the scale to read the text and
dimensions. Jerry
Did not help much. We are only an inch or two off.
I'll wait until we get the actual mm if we do.
If we can't get it we can measure the cowl.
Or we can get the thrust line dimensions relative to
the hard points from Lancair. I can call them.
Paul Lamar ...No rotor no motor.
Hey Paul,
One suggestion which might help yield more useable overlays is to have the
photographer zoom the camera in to provide the tightest view, and then
stand as far from the subject as possible, and still have the subject fill
the viewfinder. This will improve the geometry of the shot, and reduce
(parallax?) error.
Regards,
Matt-
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