mill: fish scale pattern on ways


Hi, I'm very new to machining and I just got an RF45 clone mill.
I've read as much as I can about prepping of this machine and I was
trying to figure out for myself today whether I should lap the ways.
On close inspection the ways have a sort of ground fish scale
pattern. From a distance the ways look almost like mother of pearl.
It looks like the pattern was applied manually because the marks are
not uniform in spacing. Can anyone tell be what the marks are
called, what they are for, and how they are applied? Just curious.
BTW I'm probably NOT going to try to lap the ways because 1) A well
respected guy at IH said that most chinese mills no longer need
lapping, and 2) at least to my eye, they seem much better than
pictures of others earlier machines, both before and after they
lapped. I basically understand the big debate as to whether lapping
should ever be done. --But I would still like that question above
answered.
--zeb
Reply to
tom walter
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Does it look like the bottom pic on the right?
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I've never seen an import mill with scraped ways, doesn't mean they didn't sell one. If that's what you have, the article should give you an idea of what you have. If done right, you shouldn't need to lap.
Stan
Reply to
stans4
The ways on mine look like the pic in the middle , what they call "frosted" , for oil retention .
Reply to
Snag
That's called "frosting" or "flaking." Ostensibly, it's for oil retention. In truth, it's usually just decorative. It does provide a good way to judge wear of the bed.
It was traditionally done with a hand tool called a scraper. It looks like a toothless flat file with a sharpened end. You push it into the iron. There are some roughing scrapers that have a pad for pushing them with your thigh, rather than your hands.
The basic purpose of a scraper is to refine the surface for flatness or other accuracy, depending on what's being scraped. The scrapers at Moore Special Tool used to scrape the ways and the table surface of their jig grinders to +/- 40 millionths of an inch, from end to end. When they were feeling frisky they worked it down to +/-20 millionths, just for fun. The frosting is a final touch.
However, in commercial lathe building today, it's generally done with a power scraper, which contains a solenoid or a motor and crank that stroke the scraper in and out. Manual scraping can be a workout.
I can't help with the lapping question.
Reply to
Ed Huntress
And on modern cnc machines with box ways there isn't any flaking at all. At least not on the Mori's and Okuma's I've worked on. Ways look machine ground to me.
Wes
Reply to
Wes
Wasinos had ground box ways with no flaking, but the head was hand-scraped into the bed. If a machine has pressure-fed way lubrication, there is no mechanical reason for flaking or frosting.
Most machines have ground ways today; some have frosting applied as a mostly decorative touch.
Reply to
Ed Huntress
Yes, Stan, it's like the middle picture with the intersecting circles, only mine are small arcs spaced futher apart and not intersecting so much. Thanks. Geez Wiki has everything.
Reply to
tom walter
Wes sez: ". . . .|Ways look machine ground to me. . . ."
Same on my large Comet mill which is a '92 manual model.
Bob Swinney
"Ed Huntress" wrote:
with box ways there
ed.
Wes
Reply to
Robert Swinney
In another post I said the ways on my Comet weren't frosted.. Come to think of it the knee's ways are frosted. My guess it is because of higher oil-wiping stress on the vertical areas. That knee is heavy under a 9 x 54 table..
Bob Swinney
snipped-for-privacy@prolynx.com wrote:
The ways on mine look like the pic in the middle , what they call "frosted" , for oil retention .
Reply to
Robert Swinney
OOOps! Make that 10 x 54 table.
Bob Swinney
In another post I said the ways on my Comet weren't frosted.. Come to think of it the knee's ways are frosted. My guess it is because of higher oil-wiping stress on the vertical areas. That knee is heavy under a 9 x 54 table..
Bob Swinney
snipped-for-privacy@prolynx.com wrote:
The ways on mine look like the pic in the middle , what they call "frosted" , for oil retention .
Reply to
Robert Swinney

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