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JND
03-01-2009, 11:52 AM
I am getting back into machining after a little break(20) years or so.I have a 13" S.B.I have picked up some of the old literature that is availiable,but yet to find an actual opperators manual,explaning all of the functions on my lathe. I'm having a little trouble with using a higher speed,and having a slow feed at the same time.It has a quick change gear box,which I believe eliminates all of the change gears? Is there another change gear somewhere that I'm missing that can be swapped out to lower the feed rate,or am I jut being a bonehead and not figuring out the right combination yet:confused: If anyone has an actual copie of the operators manual,I would gladly pay for a copie. Any help on the subject would be greatly apprieciated!


There are change gears on ebay right now,but if there duplicates I dont want to purchase.

Thanks.

PaulF
03-01-2009, 01:08 PM
JND,
At the PM site there is a forum about South bend lathes (Paula is moderator).
A lot of helpful people and much information.

The information you seek is contained in a small book called How to run a lathe by South Bend Lathe Works. It is available in many forms.

Check out WWW.Quarterbore.com .
Quarter bore is not the best place to go for info on South Bend lathes.
A CD I have with the book on it is from there.

Also make sure your back gear is disengaged and the bull pin is set correctly.
The back gear slows the machine to accomplish threading.

PaulF

quadrod
03-01-2009, 01:15 PM
also look at the stud gear, it is the one that drives the large idle gear. it should be a 24 tooth gear, there is a 48 tooth gear on the outboard side of the gear box feed gear, that is the larger stud gear for cutting 4 to 7 1/2 thread pitches. if you have the large gear as the stud gear you will not get any fine feed rates.

JND
03-01-2009, 10:17 PM
PaulF,I have that book coming! I hope it has everything in it that I need. I'm a member on PM also,but was checking here first.quadrod,that is exactly what it seems like! I'll check that out and see where I'm at.Is that the gear that pulls in,and out,or does it get changed with another gear?
Thanks for the replies!:)

quadrod
03-01-2009, 10:42 PM
weather it pulls in or out depends on if it is a single tumbler gear box or the later double tumbler gear box.

Mike Burdick
03-01-2009, 11:02 PM
JND,

The "equivalent" of How To Run a South Bend Lathe is Text Book of Turning by P.B. Hercus. It can be downloaded free at the following link:

http://bbssystem.com/viewtopic.php?t=89

JND
03-02-2009, 12:36 AM
The book came in,just didn't know it! I was going through it trying to figure this out. If I'm not mistaken it has a 36th.stud gear?
http://i579.photobucket.com/albums/ss240/nd69/changegears001.jpg
The gear I'm talking about is the nutted gear on the reversing lever with the black sharpie mark on it.

quadrod
03-02-2009, 12:55 AM
i think maybe your stud gear should be 18th. i could be wrong though, check this site out.
http://www.geocities.com/davesmithone@sbcglobal.net/
look at the gear box for the 10,13,14 1/2

JND
03-02-2009, 01:24 AM
Thats my gearbox! Thats the only page I've seen that shows the double wide primary gear.The parts book that I got shows the 24th.-48th. change gears that you mentioned.I wonder what other gears have been changed? This would have affected threading right? That would have sucked to figure out after machining a part.Is there a reason you can think of that someone would have put a 36th. on?

PaulF
03-02-2009, 01:54 AM
The upper lever is your back gear I think, and it looks to be ingaged.

Try moving that upper lever toward the front of the machine.

Also get a second confermation from quadrod. I have a heavy 10 and it is not exactly like yours.
PaulF

OOPS! lever back is off!!! never mind......

BigBoy1
03-02-2009, 08:10 AM
http://i579.photobucket.com/albums/ss240/nd69/changegears001.jpg


Sir,

The sliding gear in the picture (the gear with the knurled handle) is in the "out" position, causing the quick change gear box to be in the lower range, making the feeds slow. Moving the sliding gear to the "in" position, then the higher feed rates in the quickchange gearbox can be accessed.

Bill

JND
03-02-2009, 10:56 AM
Thanks Big Boy,that sounded wierd!:D I believe that was in until I started looking at the gearing,that answers my ? about the two gears that swap on the other type of gear box.Now back to the stud gear,to make the gear chart acurate I think I need the 18th.right? And are there reasons for having different stud gears if I have a quick change box,with a high and low range?