Paul


got the files  and have the material here...I have enough to make at
least 8 plates.I will  make 1 for inspection, then if you want
more......

the pressure caps  can be done as well.. get the geom and advise  on
material....

jeff

OK do we have any other buyers? Speak up  now.

Paul Lamar


Paul
can you publish the list of those that spoke up so we can verify you
have us down... Count me in.

Mike C.

I don't have a list.
People should contact Jeff directly.

jeff doddridge <4starr@cox.net

Paul Lamar


Paul, I was reflecting on the beam plate design, in it's present
configuration. I notice that the Barry cups are in essence butt
welded to the ends of the beam. Given that the welding process
destroys the heat-treat properties of the aluminum in the heat
afected zone, is this method of attachment strong enough to hold
the engine and absorb all of the forces incurred? I'm not an
engineer, but I do understand the welding process, so please
don't take offense. I'm just posing a question.
C. Smith

Absolutely.

If you take a 6.5 G hard landing drop in and assume the engine
weighs 300
pounds the shear force on the welds is 2000 pounds.
Lets assume for the moment all force is applied to only
one cup. The one closest to the engine.

If the total weld area taking both sides of the cup is .25 inch by
3 inch long
that is an area of .75 inch. .125" per side.  Therefor the stress
is 2000 / .75
or 2,666 psi. The  tig weld tensile strength is given in this
referencea about 25,000 psi so we have a factor of safety of 10.

http://www.aps.anl.gov/Science/Publications/lsnotes/ls254/ls254.html

Paul Lamar

Which is a HUGE under estimate. We are allowed to use 75Ksi in all
our welds here at my day job. [in 44w plate] W/ 7018 [or equal] welding materials.
[We're talking MIG or Stick however.. I'm not sure about tig]

Fwiw

Jarrett

Would/could you please do an FEA with 700 ft pounds of torque combined
with 1800 pounds of down force :)

Like Bob White crash. Full power full stall drop in crash landing.

Paul Lamar

I need to correct this.  The stall was pretty much power off.  I
dropped in from 30-50 ft.  (This is a total guess, but it seemed to
take forever from when it started dropping to when it hit.  I induced
the stall when I reduced power to get down a little quicker as I was
still pretty high and half way down the runway.)  I don't believe the
stall and subsequent contact with the runway caused any damage
whatsoever to the motor mount.  Later I found the tail wheel support
structure was bent. The plane hit tail first.

All the damage was done when I made a dumb decision to try to recover
with a go around.  Now plowing through the weeds at full power, either
the prop tip dug in or the left main caught on something causing the
entire aircraft to rotate about 120 degrees and come to a full stop in
50 to 75 feet.  The composite prop was completely destroyed, the shear
pin on the redrive was sheared, the main gears were ripped off, the
fuselage was bent behind the cabin doors, and the firewall was
damaged.  Damage to the motor mount was the bent support tube as shown
in the picture Paul posted earlier and a slight bend in the MM plate
between the redrive and the Barry mount.

No full stall full power landing though. :)

Bob W.