I made up a cheat sheet for setting the RPM on my minilathe for
various materials and diameters, and thought some folks here could use
it too.
Here it is in PDF:
And ODG:
The ODG file is editable with OpenOffice Draw, which is freely
available for just about any platform. You'll need this file to
change the knob RPM maps and SFM to suit your lathe & turning habits.
The PDF file is really just so you can see it without OpenOffice.
The table is a spreadsheet. To adjust it's values, right click on it
and select "EDIT". Then just change the SFM value and the other
fields will recompute. It rounds to 50 rpm unless sufficiently slow,
where it rounds to 25rpm. When you're done, just hit <ESC> and print it.
Since I have mostly HSS tooling, that's what the table is set for. I
figure it's easy enough to double the numbers mentally for carbide.
The RPMs were checked with a laser tachometer.
I hope someone else finds this useful!
-Paul Moir
