Thanks for that link Al, makes fascinating reading, but I doubt whether the information therein is of much practical value to someone with an old SB lathe! ?To put that into context, it deals only with cutting edges made from Cubic Boron Nitride, and the cutting speeds of interest range from 600 to 1200 m/ min. ?On a 9" diameter (229 mm) diameter workpiece, those are 834 to 1668 ?RPM! ?Just shows how far we've progressed.
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Eddie
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------ Original Message ------
From: arknack@...
To: [email protected]
Sent: Friday, September 20th 2024, 13:19
Subject: Re: [SouthBendLathe] MLA Crossslide
?
Here is a very technical article on tool life between aged and non-aged CI. Bottom line is aged cast Iron extend the machine tool life.
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Al
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I imagine that stress relieved where necesary actually means where appropriate.? Castings for the slides, yes, castings for a handle, no.
As an aside, I have never understood how aging at ambient temperature releases any part of locked in stresses created as a result of differential temperatures during the cooling of a casting.? I would have thought it would be necessary to apply external loads so that areas with a high residual tensile stress were forced to yield somewhat.? After all, that is what results in the deflections seen in service on castings or fabrications that have not been properly stress relieved at birth.
-------- Original message --------
Date: 20/09/2024 12:14 (GMT+00:00)
Subject: Re: [SouthBendLathe] MLA Crossslide
I purchased one of their kit several years ago. That project is still on my never ending to-do list.? The casting is well done. Stress relieved means it has been heated after casting to relieve the internal pressures so it wont warp after machining. In the old days, they would let the parts age a year or more to relieve the stresses.
Paula on Practical Machinist did a excellent article on machining these. Here is the link.
file:///C:/Users/arkna/OneDrive/Documents/Manuals/Machine%20Tools/Southbend%20Lathe/T-Slot%20cross%20slide/Machining%20A%20T-Slotted%20Cross%20Slide.htm
Al-
> -----Original Message-----
> From: [email protected] <[email protected]> On Behalf
> Of mike allen
> Sent: Friday, September 20, 2024 1:18 AM
> To: [email protected]
> Subject: [SouthBendLathe] MLA Crossslide
>?
> Has anyone here don the MLA Crossslide for a South Bend 9A lathe ? I'm
> thiking of just buying the plans & wondering do the drawings include the
> dimensions for the Gibb too ? They also mention that if ya buy the casting
> they are " stress relieved where necessary " just what does that mean ? I
> have a bud that's gonna give me the cast iron .
>?
> thanks
>?
> animal
>?
>?
>?
>?
>?
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