Spinning casting a babbitt bearing

[Ralph2]

Hello
A customer wants us to spin cast a babbitt bearing. We do this frequently but always horizontally and "smaller" than this one.
This one is to be spun vertically has a inside diameter of 48.8 inches and is 51 inches tall.
The question I have is what speed do I need to turn this to raise the level of the liquid babbitt to the required height. We will have a damn on the top to retain the babbitt from spilling out and "hope" to have a wall of at least 1" at the top. Given that, how thick will the wall be at the bottom.
My calculator does not have nearly enough buttons to figure this out. Will be using #2 babbitt but do not know the specific gravity of that. For anyone helping with this calculation use the SG of lead.
Thanks, comment on the wisdom of this process also accepted.
Ralph

 

[Barry1961]

It seems like a valid way to spin cast to me but I don't know much about spin casting. Just wondering why you can't make a std. mold? Good luck.

Barry1961

 

[EnglishMuffin]

I know nothing about spin casting. However, I do know, (or perhaps I should say "have access to&quot, a bit of physics. If your question simply amounts to asking “what is the geometry of the internal free surface of a liquid placed in a spinning cylindrical container”, then one place you can find that information is in "Handbook of Physical Calculations" by J. Tuma, page 179. The internal free surface is a paraboloid, and its shape is independent of the density of the liquid. Using the equation given there, and doing a bit of extra math, I arrive at the following conclusion:

Tb = Tt + R-sqrt(R^2 - 2*g*H/(omeg^2))

Where Tt = the thickness of the bearing at the top
Tb = the thickness of the bearing at the bottom
R = inside radius of the bearing at the top
H = height of bearing
omeg = angular velocity of container rad/sec
g = acceleration due to gravity

Hence if Tt = 1", R = 24.4", H = 51", and omeg = 41.89 rad/sec = 400 rpm (say), then Tb would be 1.465".

Based on your actual experience, does any of this look right to you, or have I screwed up somewhere? (It wouldn't be the first time).

 

[EnglishMuffin]

I should add that additional calculations need to be done to figure out the amount of liquid that you need to start with, such that the above formula is valid.

 

[Ralph2]

Thanks for your time EnglishMuffin. I appreciate your help
Ralph