Rookie Lathe Soft Jaw Questions

All discussion about lathes including but not limited to: South Bend, Hardinge, Logan, Monarch, Clausing and other HSM lathes, including imports

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SteveM
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Re: Rookie Lathe Soft Jaw Questions

Post by SteveM » Wed Jan 12, 2022 10:17 pm

Inspector wrote:
Wed Jan 12, 2022 6:30 pm
The centre punch mark would do it but then it dawned on me some Loctite would work too. That makes the soft jaws fabrication method easier and safe too.

Pete
I tried to find a pic of mine, so no success.

On mine, there's a 10-32 countersunk screw holding it in from the underside.

Steve

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GlennW
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Re: Rookie Lathe Soft Jaw Questions

Post by GlennW » Thu Jan 13, 2022 6:23 am

By the time you make the key, wouldn't it be just as quick to just mill the jaw with the key?
Glenn

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rmac
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Re: Rookie Lathe Soft Jaw Questions

Post by rmac » Thu Jan 13, 2022 7:00 am

GlennW wrote:
Thu Jan 13, 2022 6:23 am
By the time you make the key, wouldn't it be just as quick to just mill the jaw with the key?
Probably.

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GlennW
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Re: Rookie Lathe Soft Jaw Questions

Post by GlennW » Tue Jan 18, 2022 4:45 pm

Many different uses.

ID grinding steel soft jaws in the grinder.
DSC03933.JPG
DSC03934.JPG
In order to OD grind the axles on 24 of these.
DSC03935.JPG
Glenn

Operating machines is perfectly safe......until you forget how dangerous it really is!

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Re: Rookie Lathe Soft Jaw Questions

Post by Harold_V » Wed Jan 19, 2022 2:54 am

Nice setup, Glenn. Those drop-down internal attachments are really useful.

H
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rmac
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Re: Rookie Lathe Soft Jaw Questions

Post by rmac » Wed Jan 19, 2022 10:37 am

For the record, I can report a successful first use of my soft jaws. They're almost like having any size collet you want, with built in stops for repeatable Z positioning. One might even call them the magic bullet of part holding!

Still need to make that spider.

-- Russell Mac

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rmac
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Re: Rookie Lathe Soft Jaw Questions

Post by rmac » Sun Feb 27, 2022 9:32 pm

rmac wrote: Still need to make that spider.
Well here we are almost six weeks later and I finally made a spider. It's threaded for 1/4-20 screws with an OD of 1-1/4". For times when that's too big, I like Hanz's suggestion from a long time ago to just use a socket, although I haven't actually tried that myself.

I put the three extra holes in my spider so I could try an idea from one of Joe Pieczynski's videos for accurately indexing the threaded holes. The second picture shows that setup. If I remember right, Joe's video shows several variations of the same general idea.

-- Russ

spider.png

setup.png

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Re: Rookie Lathe Soft Jaw Questions

Post by Harold_V » Mon Feb 28, 2022 2:11 am

rmac wrote:
Sun Feb 27, 2022 9:32 pm
I put the three extra holes in my spider
Excellent setup!
You might consider keeping your eyes open for a few sets of drill or reamer blanks. They're exceedingly useful for making setups like that, and much more. I have at least two complete sets of numbers, letters and fractions. I'd be lost without them.

Don't know about drill and reamer blanks? Do a search. They're much more than one might imagine, and high precision.

H
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rmac
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Re: Rookie Lathe Soft Jaw Questions

Post by rmac » Mon Feb 28, 2022 3:33 pm

Harold_v wrote: Excellent setup!
Yup. It worked great. Joe Pieczynski is a smart boy!
Harold_v wrote: You might consider keeping your eyes open for a few sets of drill or reamer blanks. They're exceedingly useful for making setups like that, and much more. I have at least two complete sets of numbers, letters and fractions. I'd be lost without them.

Don't know about drill and reamer blanks? Do a search. They're much more than one might imagine, and high precision.
Much more what than one might imagine? Affordable? Fuel efficient? Effective at lowering bad cholesterol? :)

I had heard about them before this, but didn't really know what they were. I can see where you might want a few for setups like we're talking about, or for grinding an occasional tool. But why would you want a complete set? Or in your case more than one complete set? What are some other things they're good for?

Thanks,

-- Russell Mac

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Re: Rookie Lathe Soft Jaw Questions

Post by Harold_V » Mon Feb 28, 2022 5:02 pm

rmac wrote:
Mon Feb 28, 2022 3:33 pm
What are some other things they're good for?
They are useful in checking hole diameters. Considering they come in drill sizes, they readily disclose if the hole is on size or not. It's not uncommon for a drill to drill a hole that may measure size, yet a pin won't enter. That's often due to the drill in use creating a three sided hole. A pin readily discloses that condition.

They are exceptional when you're trying to align parts that share the same hole patterns.

Need to use a hole as a datum point? Drill blanks work well.

Have need to measure hole center distances? Blanks serve that purpose well, assuming you have more than one of the same size.

Inspecting hole locations on a surface plate, with the item mounted on an angle plate or knee? Pins offer the real location, assuming they fit correctly. Deltronics might be a better choice here, but who amongst us can afford those, especially for hobby use?

The reason I mentioned drill (or reamer) blanks is because they are high precision and hardened, unlike drill shanks, which are tapered and not true size. I am not critical of the use of drill shanks, for I firmly believe that all of us have used them in lieu of blanks, but they are rarely truly on size and without damage, so they may or may not offer the particular function one is attempting to achieve. Blanks help avoid that problem.

I should note that when I worked for gain, I spent the vast majority of my shop time building tooling. They are indispensable for that purpose. I learned to use them and can't work without them now. I use them regularly. Like any tool, if you have it, you use it.

H
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rmac
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Re: Rookie Lathe Soft Jaw Questions

Post by rmac » Mon Feb 28, 2022 6:02 pm

Thanks, Harold. That helps.

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SteveM
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Re: Rookie Lathe Soft Jaw Questions

Post by SteveM » Tue Mar 01, 2022 10:07 am

rmac wrote:
Wed Jan 19, 2022 10:37 am
For the record, I can report a successful first use of my soft jaws. They're almost like having any size collet you want, with built in stops for repeatable Z positioning.
We have another convert!

Steve

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