What's new
What's new

New to machining and the South Bend 9. Questions questions questions!

Oildrips

Plastic
Joined
Feb 10, 2020
Hi there.

I recently purchased this South Bend 9 to attempt to do some light duty automotive part machining. I'm hoping this lathe will satisfy my need to cut to length pushrods and trim piston barrels for their cases.

It was very clearly used as a 'farm' lathe here in Western Canada, as there is definitely some odd things about it (like the actual pant belt as a belt and the large wooden pulley) that suggest its been used remotely.

I'm having a hard time identifying which model it is. It doesn't have the driven cross feed, and it looks as though one of the rails was replaced (the one with the serial number). Is there another way to identify this?

As it doesn't have any instructions (and I don't know what model) is there any literature/websites that talk about what gear combos are used for what pitches? Can the lathe be used to cut metric threads?

I'm assuming that all of this info exists here on the forum. Any pointers/links to find the answers would be appreciated. I'm new to this, and am open to learning from your experiences.

IMG-5183.jpgIMG-5182.jpgIMG-5181.jpgIMG-5180.jpgIMG-5179.jpg
 
Thanks for this. That was my guess as well. I'm super new to this and appreciate the info.
 
Well I don't see any change gears and without them you will not be cutting threads ,plus to do metric you will need transposing gear. If you are missing those gears and only the one chuck and if the lathe is well worn you might end up with more money in it than if you would buy a better machine. Pretty much all USA made smaller lathes will need the transposing gears to do metric. The small Asian [Chinese] lathes normally will cut metric by changing a few gears that they come with. And here I am refering to 12" and larger lathes.
 
Thanks for the reply. I have a big stack of change gears that came with the lathe, and from what I can tell I'm missing the compound 18/72 gear/idler. It also came with a 4 jaw chuck. As far as it being warn, I still need to go through the lathe itself. It only showed up on Sunday. Can you explain the transposing gears?
 
Looking at that link, page 25 of the book has an idler gear. This is one I don't have.


Here is the "imperial" SB 9C chart - normally riveted to left end gear cover. Metric a whole different story, probably costing more than the lathe and its usual tooling for the set SB sold

SB 9C Chart.jpg

Here is an example of Metric-ing

Looking at the chart above for 9C, say you were set up for 8 TPI - with the 32T stud gear and the 32 T Screw gear and the 80T idler - exactly as in Figure 2

If you removed the 80T and stuck in a 127T / 100T compound (or a very similar ratio 80T / 63T) you could cut 2.5 mm thread. That is just one of many, only a few of which will be "easy" like the example

The math that determines this is using these values:

8TPI = .125" pitch (because 1 / 8 = .125, the reciprocal of 8)

127/100 = a ratio of 1.27 to 1

.125 / 1.27 = .098425" pitch

.098425 X 25.4 = 2.5 mm pitch
 
Thanks for the tutorial on this stuff. Very helpful indeed. When I look at the picture you attached, it looks like there are 2 different slide rails to mount the gears on. My lathe only has one ( so like figure 2). Nothing was cut off, just like it wasn't there in the first place. Is this normal?
 
Thanks for the tutorial on this stuff. Very helpful indeed. When I look at the picture you attached, it looks like there are 2 different slide rails to mount the gears on. My lathe only has one ( so like figure 2). Nothing was cut off, just like it wasn't there in the first place. Is this normal?

That's the way mine is too. I'm beginning to wonder if mine actually is a 9C or some predecessor? Everything else is just like the 9C but I also have the one-armed gear banjo. I'll have a look at my threading chart on the gear cover and my change gear set tonight.
 
If that picture is your lathe and you do have a stack of change gears to go with it, you probably can cut most common threads. What gears you have will determine what threads you can cut. I wouldn't worry too much about the wooden pulley. It'll probably work OK until you can find the correct one.

If you didn't get the covers for the end gears and the back gears your lathe will work just fine but be REALLY careful you don't get fingers or clothing caught in them because that could lead to very serious injury. I have a Workshop 9" lathe, Model C that looks a lot like that one (no wooden pulley) and it works very well and cuts all the threads I need.

If you want to keep it, I'd try to find the gear covers and the correct pulley for the countershaft but you should be OK for starters.

Get and read the South Bend publication How to Run a Lathe. You can find PDF copies on line. It will answer a lot of the questions you have.

So far as cutting metric threads, you'd probably be better off to buy a lathe that has "native" metric threading ability.
 
Glad I'm not alone. I'd appreciate it if you can share your findings. Are the 1 arm and 2 arm banjos are interchangeable? Do you know if the reason for the 2 armed banjos is to add additional capabilities for threads?
 
Thanks for your post. I've been very hesitant to play with the lathe without the covers for exactly this reason. The PO also mounted the power switch at thigh height, making it super easy to turn on.

I found all the gear covers and the countershaft/pulleys and have them already on the way. Safety Bear's top priority.
 
Yes. It has a wooden pulley. Does it matter? It also has some cowboy's leather belt driving the pulleys. Still spins.

I did my best to express the fact that I'm new to machining and this lathe in the title 'New to machining and the South Bend 9. Questions questions questions!', so if the topic is below you, I'm not sure why you'd bother to keep reading and then comment. I'm sorry if I seem harsh, but it was stated pretty clearly that I'm looking for guidance.

I respect the fact you already know more about lathes and machining than I do. I don't pretend to know anything, so I try to find the best resources around. I'm not interested in having heart surgery performed by someone that did their schooling by watching youtube videos. I'd like to learn from the best. Rather than shut people down who want to learn and make them feel not welcome, why not offer something positive to help out someone new instead of looking down on them and what they have to work with? It costs nothing to be helpful.
 
Yes. It has a wooden pulley. Does it matter? It also has some cowboy's leather belt driving the pulleys. Still spins.

I did my best to express the fact that I'm new to machining and this lathe in the title 'New to machining and the South Bend 9. Questions questions questions!', so if the topic is below you, I'm not sure why you'd bother to keep reading and then comment. I'm sorry if I seem harsh, but it was stated pretty clearly that I'm looking for guidance.

I respect the fact you already know more about lathes and machining than I do. I don't pretend to know anything, so I try to find the best resources around. I'm not interested in having heart surgery performed by someone that did their schooling by watching youtube videos. I'd like to learn from the best. Rather than shut people down who want to learn and make them feel not welcome, why not offer something positive to help out someone new instead of looking down on them and what they have to work with? It costs nothing to be helpful.

Well, this is the antique section of the site not the cobbled together shitbox southbend 9" section. Just because you don't know what you are doing doesn't make it ok to have a wooden pully on a lathe that you intend to actually use.

These are the best resources around you are 100% correct
 
Thanks for your post. I've been very hesitant to play with the lathe without the covers for exactly this reason. The PO also mounted the power switch at thigh height, making it super easy to turn on.

I found all the gear covers and the countershaft/pulleys and have them already on the way. Safety Bear's top priority.

Seems this may have been lost on you a long time ago
Necessity is the mother of invention - Wikipedia


I'm ok if you want to keep throwing out the insults. Whatever is going to make you feel like the better person.
 
I'm ok if you want to keep throwing out the insults. Whatever is going to make you feel like the better person.

It's not about being a better person, really, I dont even own a machine save for a small Lincoln mig welder. It the premise of this site. I'm all for allowing anyone who wants to learn on this site, there are some that will right tooth and neck to keep them off here. Its not about the machine... unfortunately to some it is. But when it comes down to stuff that's not rigged it strikes a cord.

I welcome you to learn as much as possible here.
 








 
Back
Top