I am planing on cutting a bunch of 2.5 inch holes were possible to cut

the weight.

Paul Lamar

 Paul, Have you considered using liquid honing or chemical etching to

bring down the weight of the bell housing? With proper

 masking to protect those areas where as cast thickness is required you

can then etch the web areas where the material is overly

 thick. Years ago I worked for the company that was milling the landing

gear doors for the F-15. They fought the weight spec on

 the part until they had it down to nominal and near minus tolerance

limits and could barely make weight. McDonnell Douglas took

 that part and liquid honed off two pounds while maintaining drawing

tolerances. Many years later I did ultra sonic inspection on

 chem etched panels for Boeing. They could control the process so well

they could hold +/-.002". It would probably be a toss up

 for expense of either the hand work required for liquid honing or the

time to mask the areas for chem etch. Casting porosity

 might make liquid honing the more viable of the two though.
 Rick Girard

That is a good idea Rick. A lot of this bell housing is over designed

because of casting

thickness limitations.
Paul Lamar

Paul,
I must admit, both the foundry chap and I were amazed at the weight, must be
mostly in the stiffeners. I said to him I may have to try and cut the weight
down - his response was, where!! That just about sums it up!

If there were serious demand, I'm wondering if an investment casting would
be cost effective, it certainly would solve the problem of weight and
machining . I know the product cost is very low but the set up cost could be
$10,000.00 or more - did you get any cost indications previously  Paul ?

I might do a check around.

George (down under)

Investment casting would be too expensive.
There still are  a few places on the pattern to cut the weight of the casting. Perhaps we
can do the casting here as our guys specialize in thin wall. I'll know more
when I see the casting.

Paul Lamar

George, I must have missed the email somewhere, but what does the thing weigh?

14 pounds raw Doug. PL

I borrowed this from Paul Yaw's website, but I thought some of the new people 
to the list might get a laugh from it!
Doug Mueller
RX-6 13BT
N900DM
Henderson,Nevada

 
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