>> Larry delivered the pattern by driving down from Northern California>> Thursday after noon. We drove it over to the foundry today and
>> it passed inspection and left it there.
>>
>> In fact they complemented Larry on the nice work. I am relived and
>> very happy.
>>
>> We will have ten castings next week. Larry is building a
>> test rig so they will be static tested to 600 foot pounds. The same >> torque
>> will bend the flange on a Lycoming aerobatic motor so any more than
>> 600 foot pounds does not make any sense.
>>
>> Paul Lamar ...No rotor no motor.
>
>
> Sorry if I missed this in an earlier post (and my ignorance):  what is the
> exact technique used to cast a housing with this pattern?  Is it lost-wax,
> or some other method?
>
> Scott Gettings
>
> Straight sand casting Scott. The foundry we use specializes in thin wall
> sand castings. The lost wax process would be too expensive.
>
> -- > Paul Lamar ...No rotor no motor.

An interesting point Paul, and I was interested to see how you and Larrytackled it - is that a lot of casting companies want an inner and an outer
pattern (dowel matched). That method is expensive and time consuming.
I noticed that Larry has made one pattern, which is used as an inner and an
outer ( same as the method I used). The pattern is placed flat on the back
surface ( within a frame), sand is packed around it and then it is turnedover. Another frame ( shorter) is placed over the top of the first and the
inside is filled with sand. The frames are split at the junction -
maintaining true symmetry ( inner to outer).
Copies of mast things can be achieved using this method, provided the copied
item can tolerate the 1:22 shrinkage rate i.e. difference in finished sizes.
BTW did you leave about 5mm clearance on the flexplate to
Bellhousing?
George (down under)

Yes.

Paul Lamar ...No rotor no motor.

The reality is that machining two molds would have been just as, if
not easier than doing the full pattern in one pc. It would have ment
twice as much wood, but the setup's would have been way easier.
I was going to suggest it, but knew it was not the 'normal' way of
things so I kept my mouth shut.. anyway.. I can't wait to see the
cast parts!

Jarrett

Thanks for all your help on this Jarrett. Jarret converted the Rhino IGES
files to Solid Works files. In some cases starting from scratch I think.
Thanks again Jarrett.

Paul Lamar


Jarrett,
Just because you think something may not be the standard way, please speak
up! Your input is valuable. Building the mold in 2 parts would have been
easier, and the finished molds would have been stronger (but I didn't think
of it, so that's where your input would have been great). After the
prototype run of 10 parts, I will be making the production molds to get the
cost reduced and to put any corrections in.
I have a lot of patterns to make in the near future, so anything I can learn
to shorten the learning curve helps. The owner of the foundry was also very
helpful. I will depend on his 30 years of experience to help guide what I
build as well.
Thanks again for helping Paul kick start this project!
Larry



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