South Bend 10" fine feed

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VelocityDuck
Posts: 118
Joined: Mon Dec 07, 2020 6:14 am
Location: Panama City, FL

South Bend 10" fine feed

Post by VelocityDuck »

I'm getting familiar with my new-to-me 1960's South Bend 10" lathe. I've been using a ShopTask BridgeMill 3-in-1. The tool post on that was mounted to the table so you had very fine manual control of the lateral movement.

This South Bend only has the handwheel which moves the carriage a lot with just a small motion of the handwheel. I realize that I could use the leadscrew and clutch but (for now) I'm more comfortable manually moving the carriage for some operations.

So far the only workaround that I've found is to manually rotate the leadscrew with the half-nut engaged. I attached a 7/8" socket to spare handwheel to rotate the leadscrew. It's kind of a kludge so I figure there's got to be a "right" way to do it.
John Evans
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Re: South Bend 10" fine feed

Post by John Evans »

Man up and use the power feed !
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earlgo
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Location: NE Ohio

Re: South Bend 10" fine feed

Post by earlgo »

My friend has a relatively expensive English Myford lathe and it has a graduated dial and turning handle on the outboard end of the lead screw for doing just what you are doing to get an unpowered incremental feed on the carriage.
Can't be all wrong if Myford does it.
--earlgo
Before you do anything, you must do something else first. - Washington's principle.
Russ Hanscom
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Location: Farmington, NM

Re: South Bend 10" fine feed

Post by Russ Hanscom »

What is wrong with setting the cross slide parallel to the ways and using it?
John Evans
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Re: South Bend 10" fine feed

Post by John Evans »

Setting the compound 90* to the ways is a exclent way of making fine graduated movments.
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VelocityDuck
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Location: Panama City, FL

Re: South Bend 10" fine feed

Post by VelocityDuck »

Russ Hanscom wrote: Wed Apr 27, 2022 2:40 pm What is wrong with setting the cross slide parallel to the ways and using it?
Not a thing... other than I hadn't thought about it. :oops:
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Harold_V
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Re: South Bend 10" fine feed

Post by Harold_V »

VelocityDuck wrote: Wed Apr 27, 2022 3:07 pm
Russ Hanscom wrote: Wed Apr 27, 2022 2:40 pm What is wrong with setting the cross slide parallel to the ways and using it?
Not a thing... other than I hadn't thought about it. :oops:
The cross slide of the typical lathe is not adjustable, thus it can NOT be set parallel to the ways. The compound slide (rest) is adjustable. If you choose to use that setup, the dial may be calibrated in direct movement, so each mark represents a thou of travel. Dials on cross slides can be marked to represent half that, to represent the change in diameter. You would be well served to determine how your dials are marked.

In spite of the fact that the carriage hand wheel of my Graziano is equipped with a dial, I use a long travel indicator for precise movement. It's fast and easy to use and very precise.

The use of the screw and half nut to propel the carriage should be restricted to single point threading (not for general movement of the carriage). By restricting the use of those components, you'll prolong their useful life. If they are used routinely for other functions, too much wear can be expected, with the outcome being one of the screw no longer being able to create a faithful lead. When the lead screw is used for power feed, there's usually a slot in the screw, which drives the feed mechanism. In that case, the half nut is not employed.

H
Wise people talk because they have something to say. Fools talk because they have to say something.
Russ Hanscom
Posts: 1955
Joined: Wed Mar 15, 2006 11:10 pm
Location: Farmington, NM

Re: South Bend 10" fine feed

Post by Russ Hanscom »

Sorry, wrong terminology.
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