In article ,
Gary Owens wrote:
Well, I got the mill back together, and am now learning to make chips.
Yesterday I learned about "Climb milling".
As I never finished my apprentice program 40 years ago, I have never used a
horizontal mill. I remember reading about it, but it was never a big deal
when I used Vertical mills, just chatter and bad finish. But using the
Nichols with a rack feed, It is a very big deal, the table took off, the
lever arm came up and whacked me in the elbow, and the machine made all
kinds of noises. That was a learning experience, not to be repeated.
You're lucky to not have gotten a broken arm from that lever.
You can get away with climb milling under certain circumstances:
1) A rigid machine with no backlash in the leadscrew.
2) A very light "finish cut" -- especially nice on aluminum. (The
advantage of climb milling for a finish cut is that you are not
re-cutting the same chips, which with aluminum usually results
in them being pressure welded to the workpiece.
But note the mention of no backlash in the leadscrew. This does
*not* include lever feed machines. Some Nichols mills have X-axis
leadscrews which can be enabled or disabled -- but IIRC, yours was a
pneumatic feed machine for the X axis, so it is highly unlikely to have
an X-axis leadscrew.
When I'm doing heavy milling with the lever feed, I *always* do
conventional milling, not climb milling. The latter is too likely to
break something -- including your bones.
I think my first project will be to make some "gibs" as 2 of the 4 gibs are
broken. 1 had been braised
You mean "brazed"? That is "soldered with brass", not cooked. :-)
but never ground flat, so that one took a lot of
filing to make it work smooth. Any idea what they are made out of, its not
brass, more like cast.
Cast is quite likely, though I have not taken my machines apart
far enough to examine either the X or Y axis gibs. The Z-axis one on
the head is easy to examine, of course.
Best of luck,
DoN.
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