All discussion about lathes including but not limited to: South Bend, Hardinge, Logan, Monarch, Clausing and other HSM lathes, including imports
Moderators: GlennW , Harold_V
rmac
Posts: 793 Joined: Tue Jun 26, 2012 12:48 am
Location: Phoenix, Arizona
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by rmac » Mon Mar 21, 2022 7:38 pm
Today I saw this in an email discussion group where they were talking about setting the cross slide on the lathe:
Always approach an OD cut by turning the dial clockwise and tapping the handle with your knuckle for the last .010-.020" to approach your reading. If you overshoot the mark you want, turn back a half turn of the dial and come back to the reading on the dial you want.
They gave the idea behind the technique as this:
It puts some tension on the leadscrew and tends to remove any "stiction" on the ways. Produces a much more accurate part than just trying to "turn the dial to the reading".
Is this common practice? I'd never heard of the "tap the handle with your knuckle" part before.
-- Russell Mac
GlennW
Posts: 7287 Joined: Sun Apr 15, 2007 9:23 am
Location: Florida
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by GlennW » Mon Mar 21, 2022 8:12 pm
I can't say that I've tapped anything with my knuckle, but I always approach a dial reading from the same direction, toward the surface to be cut.
Glenn
Operating machines is perfectly safe......until you forget how dangerous it really is!
Bill Shields
Posts: 10589 Joined: Fri Dec 21, 2007 4:57 am
Location: 39.367, -75.765
Contact:
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by Bill Shields » Mon Mar 21, 2022 8:31 pm
Depends on how many callouses and hair you have on your knuckles...
Too many things going on to bother listing them.
rmac
Posts: 793 Joined: Tue Jun 26, 2012 12:48 am
Location: Phoenix, Arizona
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by rmac » Mon Mar 21, 2022 9:02 pm
GlennW wrote: I always approach a dial reading from the same direction, toward the surface to be cut.
Yeah, that's Backlash 101. It's the knuckle tapping thing that surprised me.
ctwo
Posts: 2996 Joined: Tue Mar 27, 2012 12:37 pm
Location: Silly Cone Valley
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by ctwo » Tue Mar 22, 2022 2:49 pm
It is a technique that might help you stop on your number. I see Abom79 do it. I don't usually do it but have.
Standards are so important that everyone must have their own...
To measure is to know - Lord Kelvin
Disclaimer: I'm just a guy with a few machines...
mcostello
Posts: 963 Joined: Sat Jan 04, 2003 10:45 pm
Location: Lancaster, Ohio
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by mcostello » Tue Mar 22, 2022 9:01 pm
Don't You have a calibrated MK 1 knuckle to go with the MK1 eyeball?
Bill Shields
Posts: 10589 Joined: Fri Dec 21, 2007 4:57 am
Location: 39.367, -75.765
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by Bill Shields » Tue Mar 22, 2022 9:20 pm
I am in mk 2 eyeballs...glasses
Too many things going on to bother listing them.
Mr Ron
Posts: 2126 Joined: Tue Dec 22, 2009 12:36 pm
Location: Vancleave, Mississippi
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by Mr Ron » Tue Mar 22, 2022 10:32 pm
I've always pulled back on the cross slide while turning in the cross feed. This takes out the slack in the screw.
Mr.Ron from South Mississippi