SRF wrote:

Just got a South Bend 10" Heavy and the ways are just slightly worn near the
chuck (you can just barely feel a ridge with your finger nail). I called a
place that rebuilds and to grind the ways and scrape the various parts back
to fit would be $6,000. Yeah, right. Starting to learn hand scraping but
that's a big job plus I still have all the other parts to fix up after the
ways are ground or scraped. From a practical standpoint, I'm just a
beginner so this is probably not worth worrying about for a while.


Well, that may only be a few thousandths. If the wear on the front and
back way are similar, it really makes little difference in the accuracy of
the machine. If only the front way is worn, then the saddle will tilt, and
that can make the diameter error worse. $6000 sounds quite a bit high.
How about just grinding it, and doing the scraping yourself? You'll
learn a lot, and it may not be a big job to scrape it after the grinding
cleans
it up to almost perfect.

One question, though. Is it a hardened bed? That is a real bear to
"scrape",
as I have found out the hard way! I have been working over a Sheldon 15"
lathe with a hard bed, and chromed cross slide. The bed was a total bear
because it is so big, but the cross slide is almost worse, as it is
incredibly
hard!

So, almost a hypothetical question - since the ends of the ways are still
perfect, wouldn't it be possible to use one of those little home plating
systems to add nickel or chrome to the areas that are worn and then scrape
them to the original contours? Seems like it would be a lot less work.
Since this doesn't seem to be the common way to go I'd like to be
enlightened as to why.


I have some real doubts that would work real well. Home plating, you mean
the thing with a couple of AA batteries and a brush? That applies metal by
the nanometer. If you tried to plate up .003" of wear, you might not be
able to complete the repair in this century! You'd probably need to apply
the Nickel or Chrome immersed in a bath, with a current of amperes, for
a week to build up .003" of wear. (This .003" is just a wild guess of the
wear as you describe it.)

Flame spraying of hard Chrome or some similar material could build up
the low spots, then you'd probably build up the entire bed with a thin layer
of the hard facing. Then, it is ground smooth and straight, and generally
not touched up any after that.

But, if grinding the whole bed is going to be needed, you might as well
just do that, only, and be done with it! As far as I know, you can't flame
spray a bedway without having to grind it smooth afterwards.

Jon