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SB9 Reverse

 

I was reading the thread about the Birmingham chuck and it got me to thinking about the limitation of a threaded chuck. Has anyone come up with a way to secure the chuck to enable running the lathe in reverse? Preferably, it would not involve modifying the spindle. Work small enough for a collet can of course be run in reverse, but I am thinking about work that must be chucked.
 

Desperation Station:

1)? Apply enough plumber's Teflon tape to the spindle to make it quite difficult, but not impossible, to tighten the chuck against its stop;

2)? Take many light cuts;?

3)? Run slow enough to be able to intervene and stop the chuck when/if it starts to back off the spindle.

This has worked well enough for me, used very occasionally on my 1961 SB9A, to forestall the need to spend huge money on an alternative (stronger) system.

Mileages always vary ...
 

A big grub screw, hexagon socket style, bearing down on the spindle thread with a copper slug interposed to prevent damage.

?

Eddie

?

------ Original Message ------
From: lhm@...
To: [email protected]
Sent: Thursday, January 16th 2025, 22:02
Subject: Re: [SouthBendLathe] SB9 Reverse
?

Desperation Station:

?
1)? Apply enough plumber's Teflon tape to the spindle to make it quite difficult, but not impossible, to tighten the chuck against its stop;
?
2)? Take many light cuts;?
?
3)? Run slow enough to be able to intervene and stop the chuck when/if it starts to back off the spindle.
?
This has worked well enough for me, used very occasionally on my 1961 SB9A, to forestall the need to spend huge money on an alternative (stronger) system.
?
Mileages always vary ...
?
?
 

Mike:

I have had good success running in both forward and reverse by making a backing plate that uses a re-machinable #3MT Arbor?

?
which I press fit into the backing plate.? Now I just put the thread protector on the spindle of my SB9 lathe and insert the chuck directly into the spindle.?

My driving force behind solving this "reverse" problem with a threaded chuck is that I wanted to single point thread in reverse so that I could take all of the "crash" drama out of threading.? Now I just use whichever chuck is best for my project without regard to unscrewing the chuck while in reverse.

Success!

Capt. Art


On Thursday, January 16, 2025 at 04:14:49 PM EST, Mike Poore via groups.io <mpoore10@...> wrote:


I was reading the thread about the Birmingham chuck and it got me to thinking about the limitation of a threaded chuck. Has anyone come up with a way to secure the chuck to enable running the lathe in reverse? Preferably, it would not involve modifying the spindle. Work small enough for a collet can of course be run in reverse, but I am thinking about work that must be chucked.
 

reminds me ...? back in my stash I have a chuck with a MT5 arbor ... any interest I will dig it out and get better info.? It is about an 8 inch as I foggily remember..
 

often you can move the tailstock into or very near the workpiece while in reverse ... to prevent it from totally unscrewing so far or flys off.?
 

I had an Emco chuck that had a locking collar on the back of the chuck. ?Similar idea to the attached picture. ?I traded it to a friend as I don’t use reverse. ?Assuming he still has it I could get some actual pictures.
 

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Pictures AND dimensions,? always.

Get

From: [email protected] <[email protected]> on behalf of John Walker via groups.io <johnwa27@...>
Sent: Friday, January 17, 2025 10:54:36 AM
To: [email protected] <[email protected]>
Subject: Re: [SouthBendLathe] SB9 Reverse
?
I had an Emco chuck that had a locking collar on the back of the chuck. ?Similar idea to the attached picture. ?I traded it to a friend as I don’t use reverse. ?Assuming he still has it I could get some actual pictures.
 

Interesting replies. My idea was some sort of split locking collar, which John mentioned. Using the taper has drawbacks in that the you cannot pass work through the spindle along with increasing the overhang of the chuck. The set screw idea seems like it would work without damaging the spindle. I would not be entirely against a small modification to the spindle if it made the lathe more versatile. I see some Atlas/Craftsman lathes have flats on the spindle shoulder that could be used with a locking collar. I don't think there is enough meat on a SB9 collar to do the same. It would be nice if it did as that would be a good place to put a thin wrench to remove a stuck chuck.
 

Here’s the first pic. ?This is as manufactured by EMCO. ?Word is that it works fine. He has also made his own locking collar for a 3jaw. ?More pictures will be coming.
?
John
?
 

Here’s a ?better picture of the 4jaw

and the 3jaw
 

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That looks like it will work for reverse. As long as you are not doing heavy/hard turning.

Al

?

From: [email protected] <[email protected]> On Behalf Of John Walker via groups.io
Sent: Sunday, January 19, 2025 5:08 PM
To: [email protected]
Subject: Re: [SouthBendLathe] SB9 Reverse

?

Here’s a ?better picture of the 4jaw


and the 3jaw
 

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I think my belt would slip before this would unscrew. I will have to put this on the to do list. Thanks for the photos.

On 1/20/2025 8:32 AM, ww_big_al via groups.io wrote:

That looks like it will work for reverse. As long as you are not doing heavy/hard turning.

Al

?

From: [email protected] <[email protected]> On Behalf Of John Walker via groups.io
Sent: Sunday, January 19, 2025 5:08 PM
To: [email protected]
Subject: Re: [SouthBendLathe] SB9 Reverse

?

Here’s a ?better picture of the 4jaw


and the 3jaw
 

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The backplate squeezing collet works very well and you can take normal cuts in each direction. Had this setup on a Emco Compact 8. I highly recommend it.?

You can implement it easily on a SB 9a. It is basically the same thread size (only not metric) as the Emco.

Get

From: [email protected] <[email protected]> on behalf of Mike Poore via groups.io <mpoore10@...>
Sent: Monday, January 20, 2025 8:41:26 PM
To: [email protected] <[email protected]>
Subject: Re: [SouthBendLathe] SB9 Reverse
?
I think my belt would slip before this would unscrew. I will have to put this on the to do list. Thanks for the photos.

On 1/20/2025 8:32 AM, ww_big_al via groups.io wrote:

That looks like it will work for reverse. As long as you are not doing heavy/hard turning.

Al

?

From: [email protected] <[email protected]> On Behalf Of John Walker via groups.io
Sent: Sunday, January 19, 2025 5:08 PM
To: [email protected]
Subject: Re: [SouthBendLathe] SB9 Reverse

?

Here’s a ?better picture of the 4jaw


and the 3jaw

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