Re: Southbend 9" lathe table in CONCRETE?
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I personally love the idea!
The highest precision lathes I know of, which are capable of producing optical surfaces to an accuracy of 1/4 wavelength of light, are mounted on granite slabs. In place of the everyday optical scales, these lathes use laser interferometers. I don't recall the details of the motion control, except it's not lead screws like we have.
I've been toying with making a concrete table for a lab balance for a number of years, as I cannot afford the "synthetic granite" tables widely used in industry.
Back to the SB lathe on concrete: the problem that needs a solution is that of fastening the lathe to the concrete and leveling the lathe--making it turn a true cylinder.
I have recently gone through the exercise of estimating what I could gain by replacing my 1.5" plywood table with a 3/4" 6061 aluminum plate. I concluded it is entirely doable. The attraction is that it is not hydroscopic. The thing I haven't looked at is what issue is presented by the range of temperatures in my unconditioned garage shop and the difference in temperature coefficient of expansion between steel and aluminum.
I'm interested in your progress if you decide to pursue concrete. If you take a look at engineered stone, like Cambria, Caesarstone, or Silestone, let us know your conclusions.
David W. Pennington
On Friday, December 27, 2019, 9:12:03 AM MST, Steven Schlegel <sc.schlegel@...> wrote:
With all of the discussions about lathe tables, I have to ask: What is your opinion about making one out of concrete? I have heard they are very dead (no spring) so makes turning a lot easier. As I approach putting my 1940 SB 9” A and C lathes into operation, I am planning ahead for the tables.