Reworking 9" SB tailstock KEY REMOVAL

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p pfeiffer
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Joined: Fri Apr 29, 2011 12:58 pm

Reworking 9" SB tailstock KEY REMOVAL

Post by p pfeiffer » Sun Feb 04, 2018 10:49 am

I am making a lever action tailstock for my 9" SB lathe. Can anyone clue me in as to how to remove the spindle key? I've tried prying with a screwdriver and pulling with pliers. The stock I have is 1.063" O-1 ground and polished, but bore is tight at both ends. I think it would lap out OK IF I could get the key out of the way. There doesn't appear to be any hole to help with this. Maybe I could drill up to the key and then push it out with a pin? All suggestions welcome. Experience prefered. Has anyone ever dealt with this problem?

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wlw-19958
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Re: Reworking 9" SB tailstock KEY REMOVAL

Post by wlw-19958 » Sun Feb 04, 2018 11:07 am

Hi There,

It has been a long time but I know the key is installed
with babbit/solder. I don't know if it is threaded as well.
If you clean all the paint (and/or crud) off the underside
of the front of the casting, you will see the whiter metal
of the babbit (or solder). So, you are going to have to heat
up the casting to melt it out.

Good Luck!
-Blue Chips-
Webb

p pfeiffer
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Re: Reworking 9" SB tailstock KEY REMOVAL

Post by p pfeiffer » Sun Feb 04, 2018 11:17 am

Thanks much! That adds up, as the same installation is used on the gear cover hinge pin. Babbit. Mine has been rebuilt with steel shims. Ugly, but functional.

p pfeiffer
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Re: Reworking 9" SB tailstock KEY REMOVAL

Post by p pfeiffer » Thu Feb 15, 2018 1:50 pm

I'm back. I found the whiter metal, and heated to red hot with acetylene, even inverted it hoping that it might fall out, but no luck. Nothing melted or dripped or even softened, as far as I can tell. I still want it out, but not destructively so! HELP, please.

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wlw-19958
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Re: Reworking 9" SB tailstock KEY REMOVAL

Post by wlw-19958 » Thu Feb 15, 2018 3:54 pm

Hi There,

I haven't ever needed to remove the key before
and I thought it was held in place with babbitt.
It appears I was in error.

I found a thread about key replacement on a
SBL 10L (old style) tailstock that should give
you some help. The nine inch model and the
older 10L used the same key (according to its
part number: PT286NR1).

Tailstock Key Removal - How To?

Good Luck!
-Blue Chips-
Webb

spro
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Re: Reworking 9" SB tailstock KEY REMOVAL

Post by spro » Thu Feb 15, 2018 8:33 pm

Good link.. I didn't know why a key would be removed when it is definitely required for a lever tailstock. Heck, I didn't know it was an angled pin . No wonder they become sloppy. I can see where the levered tailstock used for MT# 2 drills would really wear out a small pin key.
Hopefully we can find a better solution than that. New barrel and new slot would like a longer key.
Easy to say this but how to do it. The reason it was angled was because the pin presented a longer surface to the slot. Who wants to drill thru the depth of the tailstock to make it different. I don't own one but expect the casting is different, allowing a longer key. The longer key makes the travel shorter too.

p pfeiffer
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Re: Reworking 9" SB tailstock KEY REMOVAL

Post by p pfeiffer » Fri Feb 16, 2018 9:00 am

I think the main reason for the angle of the key is because there is so much cast iron directly under the key. The "nose" on my tailstock casting is short, maybe 5/8. The key is back in the bore more like 1.00 inch. It would be very difficult to put it in perpendicular to the bore.

I think it might be worth it to replace it with something heat treated for wear. But getting the angle, the penetration, the alignment, the size all correct might be tough. (???)

Russ Hanscom
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Re: Reworking 9" SB tailstock KEY REMOVAL

Post by Russ Hanscom » Fri Feb 16, 2018 2:12 pm

Before you decide to heat treat or harden it, decide which you would rather have wear out and have to replace again in the future - the key or the quill!

spro
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Re: Reworking 9" SB tailstock KEY REMOVAL

Post by spro » Sat Feb 17, 2018 1:07 am

Russ Hanscom wrote:
Fri Feb 16, 2018 2:12 pm
Before you decide to heat treat or harden it, decide which you would rather have wear out and have to replace again in the future - the key or the quill!
That is a particularly good point.

p pfeiffer
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Re: Reworking 9" SB tailstock KEY REMOVAL

Post by p pfeiffer » Wed Feb 21, 2018 2:15 pm

OK I've found the white metal. But this thing won't budge. I haven't tried pounding with heat yet, but that seems to be the next option.

spro
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Re: Reworking 9" SB tailstock KEY REMOVAL

Post by spro » Wed Feb 21, 2018 7:09 pm

Our friend Webb (one of our mentors) linked to the site where that pin was removed without encountering "white metal". It is a good read. At some point, someone said they could drill into it, meaning it wasn't HS steel. If a center punch is driven into a divot of that diameter, it expands the diameter. Remember that steel is going somewhere. If it isn't drilled, milled or evacuated it is displacing the outer diameter.
So that means a center punch or smaller punch is expanding the diameter.
You wouldn't see this normally. The work asks for an answer. .
I guess everyone knows about drifts of concave faces.

p pfeiffer
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Re: Reworking 9" SB tailstock KEY REMOVAL

Post by p pfeiffer » Sat Feb 24, 2018 3:29 pm

No, I can't say I knew about drifts with concave faces, but I get the concept. (Don't mushroom a pin if you are trying to push it through!) Well, it is out now. Heat plus flat faced punch, held with vise grips (to prevent burns and/or flying punches). And lots of hammering. I suppose South Bend figured it was a near permanent installation. It is definitely steel, tight push fit/drive fit, not tool steel hard, but maybe a little. It didn't really need replaced. I may put the same one back in the tailstock.(?) But as I have said before, it was in my way.

I have some 1.063" O-1 shafting, polished and ground that wouldn't go in. I'm making a lever action tailstock. I cut a piece of shaft down to 1.0615" at one end and it fits very nicely. The other end is a little bigger and will not pass without a lot of twisting and pushing. So I guess I will have to trim the diameter slightly for my lever action. Once I have my prefered fit on the shafting, I will cut the keyway and replace the key.

Thanks for all the help. Now I know. Paul

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