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 reference
as 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


The automated welding process described isn't something that could be done
anywhere near my neck of the woods.
I was taught that aluminum TIG was an AC process, and automatic scraping
wire feeds is pretty expensive set-up.
I have a high frequency square wave inverter machine
(http://www.htpweld.com/products/tig_welders/tig201.html), and pure argon
shielding gas. The balance is adjustable, and between the high frequency and
balance, the HAZ can be controlled to good degree.
Do you have a shop that can do that process? Is it a requirement of the
design?
C. Smith

Any half ass tig welder could weld this. I don't know about stick
or MIG welding. All my experience is with tig. Most commercial stuff done
today is done with MIG. TIG is aero-space.


I think even I could do it with a bit of practice :)

The thing about welding aluminum is the configuration of
the joint is critical. An inside corner like this is a piece
of cake with .25 thick material. The hardest is a butt joint
in thin material.  This is not a butt joint.

Paul Lamar