Paul, on the casting thickness you need to consult some of the Boeing

casting

engineers. They won a prize sponsored by the American Foundry Society.
They designed a new support for the fan housing of the 737. It replaces
a bunch of parts of course but the part I found interesting is that they
have used wall thicknesses as low as .08 inches. Thats right EIGHT

HUNDREDTHS

of an INCH! I thought they had a misprint so I checked. Probably some

million

dollar mold. Not pratcial for us, but interesting anyway. Makes sweating

to

get 4mm (.160in for the metrically challenged) seem trivial by

comparison.

They are using D357 as a material. Amazing really.
Bill Jepson
P.S. George, don't feel feel bad since they probably took 2 years
to design the mold. And charged a zillion dollars for it!

Bill,
Boy it a real dilemma trying to balance need against availability, cost
effectiveness and volume of demand.
We could make one beautiful (pressure cast) bellhousing, if we could sell a
few thousand of them, buy in reality that's not going to be the case.

I've even thought of perhaps China - then dismissed that idea considering
all the horror stories where many people have been relieved of their cash
and have little if anything to show for it!!

 I do have a contact over there, but not in the foundry business - he is a
Vision builder however.

George (down under)

Don't worry about it George. Sand casting is the way to go for these
quantities. The wall thickness is what it is going to be. Some foundry outfits
are better than others but nobody is going to get it much thinner
than about 4 mm. You have already made the major investment in terms
of your time on the sand cast pattern. Lets focus on improving the
pattern and removing unnecessary material. There are some areas that
can be lightened by the customer using hole saws but are not practical 
to do in the casting or machining process. I will explore that when I 
get it. 

What can be done in the casting to save weight and cost should be done.

Paul Lamar

 
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