# 1952 16/24 SB Lathe QC gear set up.



## yeshin (Jan 26, 2015)

i have 1952? 16/24 SB lathe s#7631HKX12.  

does anyone  you know how can i access the top most row on the quick change gear? (4 thru 7 tpi)

The row is  marked with "stud gear" of 48 with "Left Hand Tumbler" on "A"

I have been using this lathe for number of years w/o fully utilizing all of its capabilities.

Also is there a manual for this lathe?

Thanks in advance.


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## Bill C. (Jan 26, 2015)

yeshin said:


> i have 1952? 16/24 SB lathe s#7631HKX12.
> 
> does anyone  you know how can i access the top most row on the quick change gear? (4 thru 7 tpi)
> 
> ...



I admit it been to long since I ran a SB.  I think you shift the handle in front of the gear cover on the left front.  I saw a drawing on this webpage http://www.lathes.co.uk/southbend9-inch/.  I think the same lever dis-engages the gear train that drives the QC box if moved to the middle.  I think that is correct.  I do know the lever on the back side is to put the lathe in back-gear.  I used to setup and run SB lathes years ago.  Hopefully others will comment on your question.  I did see a manual on a CD for sale.


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## DoogieB (Jan 26, 2015)

You have to change the stud gear for the topmost column.

Your lathe is slightly different than my 10K.  On mine, you use 20T stud gear for the bottom 5 rows of the thread chart that are the common threads.  To cut 4-7 TPI threads, you have to use a 40T stud gear.  On the 10K lathe, this is stored on top of the 56T gear that drives the QCGB.

If you look at the bottom right hand picture in this thread, you can see the stock setup.  Your lathe should be similar.

http://www.hobby-machinist.com/showthread.php/27287-Metric-Transposing-Gears

The manual is "How to run a Lathe" printed by South Bend.  There's millions of copies floating around and scans online as well.


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## atwatterkent (Jan 27, 2015)

My 14 1/2 supposedly has the same QCGB as the 16. It uses a 24T gear for 8-224 threads and 48T for 4-7 threads. 
The 48T gear is mounted to the left of the QCGB drive gear.


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## yeshin (Jan 28, 2015)

atwatterkent said:


> My 14 1/2 supposedly has the same QCGB as the 16. It uses a 24T gear for 8-224 threads and 48T for 4-7 threads.
> The 48T gear is mounted to the left of the QCGB drive gear.



So... that's where 48teeth stud gear was hanging around all these years...

Thanks All:thumbzup3:


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