On Tue, 8 Aug 2017 00:12:50 -0000 (UTC), bob prohaska
wrote:

I just acquired a wood office desk made in the 1930's which looks
like it would make a good bench for my South Bend 10k lathe. The
desk has lots of drawers, very helpful for all the little (and some
not-so little) hunks of metal that come to roost around metalworking
machines.

The top is 50 by 34 inches and about two inches thick. Because of its
age I'm fairly sure it isn't ersatz wood, but rather plywood or possibly
even solid wood. The joinery is well done, the cabinetry straight-grained
and clear of knots. It's a smaller and less-ornate version of this:
https://www.facebook.com/LincolnDesks

The obvious approach is to just bolt the lathe and countershaft to the
top of the desk, that wouldn't be any worse than the table it's on
now. The lathe is far stiffer than either and straighter to boot.

I wonder if it might be better to bolt the lathe and countershaft to
a sheet of half-inch or so plywood, just strong enough to support
belt tension (which isn't all that great, there's a prop rod 'tween
headstock and countershaft assembly) and place it on a cushion atop
the desk. That isolates the lathe from irregularities in the desk,
the cushion will serve to absorb at least some vibration.

Has anybody tried something like this? It's hard to believe a bench
contributes much if anything to the stiffness of a machine tool, but
it could contribute to vibration damping.

Thanks for reading, and any thoughts.

bob prohaska


Machine tools are normally "leveled" which doesn't always mean "level"
:-) In the case of a lathe it would mean that there was no twist in
the bed and while it can be leveled with a precision level (.0001" in
1 foot accuracy) it can also be done by cut and try. Or, if you have a
"test bar", i.e. a bar the length between centers on your lathe with
centers drilled in it that is straight and concentric you can simply
mount it between centers and hold a dial indicator in the tool post
and crank the carriage down the length of the bar. There should be no
deviation.

Most people don't have a test bar so the usual method is to cut a
piece of bar stock the length between centers, drill center holes in
it, mount it between centers and take a cut the full length of the
bar. Mike the bar, it should be the same diameter from end to end....
assuming that your tail stock is properly aligned, of course.

But to be honest, most "home craftsmen" usually spend their time
frigging about down at the head stock end of the bed and usually don't
turn things the maximum length possible. A rifle barrel, for example
:-)

So depending on your use "leveling" may not be a critical item on the
agenda :-(

--
Cheers,

Schweik