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Chris165
09-07-2011, 07:44 PM
I recently purchased a 1929-1930 16" South Bend lathe and the back gears are frozen. I tried pb blaster with no results. The back gears do not have the single large oil hole, it has the two small push in ball oilers. Any ideas on how to fix this problem?

Chris S.
09-07-2011, 08:40 PM
Is it a rust bucket?

Chris

gvasale
09-07-2011, 08:49 PM
buy a gallon of diesel or kero. take off the back gear assembly and soak them for a few days if you can, occasionally tapping the gears to check the progress. Otherwise, heat and regular penetrating oil and the same gentle tapping routine.

SGW
09-07-2011, 08:54 PM
Here's a WAG:
I don't know if that lathe has the same setup on the back gears as my 10K, but if it is there should be some kind of friction adjustment screw to hold the gears in mesh. That might be too tight. Or is the problem that they won't turn?

Tony Ennis
09-07-2011, 09:17 PM
Is it possible the bull gear and the back gears are both engaged? Of course this is Atlas speak, not 16" speak...

Evan
09-07-2011, 10:01 PM
Explain a bit further please. Do you mean that the back gears will not turn on the shaft they run on even though disengaged from the spindle?

Chris165
09-08-2011, 07:46 AM
The lathe is in very good condition. The previous owner had it painted and he never used it for turning work. It had a special fixture that he used with a boring head to bore go kart engine blocks.
The back gears will engage/disengage but they will not rotate.

aboard_epsilon
09-08-2011, 08:07 AM
don't get them to turn ..just disassemble them . and clean

some small parts are there..watch for them

all the best.markj

JCHannum
09-08-2011, 08:20 AM
Will the back gears, as a unit, turn on their shaft when not engaged with the bull gear?

Arcane
09-08-2011, 11:34 AM
You aren't forgetting to unpin the spindle when you engage the back gears, are you? I only ask because I see you are a new member and I'm thinking you might not be experienced in using lathes.

BTW, welcome to HSM.

Chris S.
09-08-2011, 02:09 PM
You aren't forgetting to unpin the spindle when you engage the back gears, are you? I only ask because I see you are a new member and I'm thinking you might not be experienced in using lathes.

BTW, welcome to HSM.

Now this is a really good example of deductive reasoning! ;)

Paul Alciatore
09-08-2011, 06:07 PM
Guys, he said in post #7 that they will not rotate WHEN DISENGAGED.


The lathe is in very good condition. The previous owner had it painted and he never used it for turning work. It had a special fixture that he used with a boring head to bore go kart engine blocks.
The back gears will engage/disengage but they will not rotate.

They obviously have frozen on their own bearings, probably dried grease (or oil) since he says there are grease (or oil) fittings. It needs to be soaked with penetrating oil/solvent/WD-40/or some other solvent for some time to penetrate this dried grease/oil. Try to force some of the solvent into the grease fittings.

One caution, DO NOT try to force it loose while engaged with one of the other gears to hold it or to apply force. One of the biggest problems with lathes listed for sale is busted back gear teeth. You CAN break them. EASAILY!!!

After freeing them, disassemble and clean throughly. Check the SB manual for this model and use the appropriate grease or oil, DAILY. Actually, do that for the whole machine.

Chris165
09-08-2011, 06:12 PM
You aren't forgetting to unpin the spindle when you engage the back gears, are you? I only ask because I see you are a new member and I'm thinking you might not be experienced in using lathes.

BTW, welcome to HSM.

Thanks for the welcome.
My experience is with cnc equipment. I used to run a Mazak QT10, SQT100MSY 5 axis lathe with live tooling and a Hass VF4. I also used a large Nardini and a small Clausing. I do small machine work in my personal shop and purchased the south bend because my two sherline lathes will not handle all the things I want to build.



As far as the south bend this is my first time owning a piece of old American machinery.
The pin on the bull gear is disengaged and the back gears will move in and out. However they will not rotate on the shaft.

topct
09-08-2011, 06:33 PM
The pulleys are stuck to the spindle.

RichardG
09-08-2011, 06:46 PM
If you can take a sharp chisel and take out the push type oil fitings and try to get some pb blaster or some such in , maby a little air to force some in along with some light taping with a hammer and keep trying to work the gears back and forth they will come loose at some point just have to work at it. Good luck
Richard

Chris165
09-08-2011, 06:47 PM
Exactly, the gears are stuck to the shaft

Chris165
09-08-2011, 06:49 PM
Guys, he said in post #7 that they will not rotate WHEN DISENGAGED.



They obviously have frozen on their own bearings, probably dried grease (or oil) since he says there are grease (or oil) fittings. It needs to be soaked with penetrating oil/solvent/WD-40/or some other solvent for some time to penetrate this dried grease/oil. Try to force some of the solvent into the grease fittings.

One caution, DO NOT try to force it loose while engaged with one of the other gears to hold it or to apply force. One of the biggest problems with lathes listed for sale is busted back gear teeth. You CAN break them. EASAILY!!!

After freeing them, disassemble and clean throughly. Check the SB manual for this model and use the appropriate grease or oil, DAILY. Actually, do that for the whole machine.

I do not have the manual for the lathe. I have been told it is an O series. Do you know where to get a manual?

aboard_epsilon
09-08-2011, 06:57 PM
Exactly, the gears are stuck to the shaft

the gears are part of the shaft ..
the shaft is stuck in the cam-bearings ..

take the little screws and detents out of the back ..and pull it apart..it rides on cams at each end ..

its quite simple ..all will be revealed when you disassemble.

all the best.markj

Chris S.
09-08-2011, 07:01 PM
Guys, he said in post #7 that they will not rotate WHEN DISENGAGED.

Well, it sounded good at the time. Yup, I missed that.

toolmaker76
09-08-2011, 07:48 PM
You might try googling your lathe model and look for pdf files in the results. I found a manual for my Sheldon lathe and also a military manual for my 9" South Bend. You can always purchase a manual from a variety of places, but some of the older stuff will probably have a manual posted somewhere for download.

Chris S.
09-08-2011, 08:01 PM
I do not have the manual for the lathe. I have been told it is an O series. Do you know where to get a manual?

We have quite a few manuals here.
http://finance.groups.yahoo.com/group/southbendmanual/?yguid=197128120

Note: SB manuals were printed showing a given part diagram from the 10L to the 16". The parts list breaks them down between models.

Chris

SGW
09-09-2011, 08:30 AM
See reply #18. I think that's the thing to try before getting more violent.

Chris165
09-09-2011, 10:18 PM
Thanks to all for the help.
Tonight I put 3 in 1 oil in every possible spot on the back gear shaft. Then applied a large punch to the tapered pin on the right side bushing and hit it until the eccentric shaft popped out. While it was removed I cleaned the oil holes and oiled the shaft.

Now the lathe is in perfect working order.