Carriage stop for the lathe

[KWK]

I converted to an electronic lead screw so it only runs when needed and I thread with the tool upside in reverse so there's no chance of a crash. I hated those sloppy change gears for threading. I also use WD-40 on aluminum. What year were your South Bend 9s made?

The electronic lead screw is interesting. I've seen videos; Change gears would be no fun. Couple reasons I don't thread in reverse. One is I have a threaded spindle nose and there's always some (a small risk) risk of spinning the chuck off onto the ways. Second is I'm pretty good at hitting the groove where I end the thread, and trust me I try to thread at a pretty good clip. Experience. Third is the fact that most spindles are designed to take more thrust cutting toward the chuck.
One of my little South Bends is 1947. 4 ft bed. I know because 1947 beds were different than the other two bed types used on them. They only made it that way 1 year. It's in very good condition. Hard to find them like that. But there are still a few out there. My other one 3 ft bed is from around the 60's or so because it has a plunger type tumbler gear selector. I think that started in the late 50's. And I also think SB9's were made up to '69.
I know I could get the exact date from Grizzly since they own South Bend for some time now but it doesn't matter to me. It's just trivia. The serial number on a SB is on the bed back near the lead screw bracket screws. An X in the serial # means special order. My later lathe has 2 X's. One is for the rare hardened bed. Very few SB9's have a hardened bed.
The reason we tend to lubricate aluminum when machining is it bonds to the cutting edge otherwise. I don't worry about it so much on a lathe because you can usually flick that off with your fingernail. For me it's more of an issue when drilling or milling. I'm not a fan of dumping oil all over everything I turn. It's just not necessary. A good finish is more so the result of proper tooling. Given that, a die maker told me to use kerosene on aluminum, even though it's not a secret as such, so I tried it and yes, it's the best! But I can get an excellent finish dry as well. Aluminum is easy, it's almost hard to not get a good finish.
I single pointed this little .166 x 36tpi thread right up to the shoulder last week. It's a proprietary thread tor a prewar BSA rifle. You can't let concerns about crashing distract you. If I do my eyeballs will start zig zagging as I near the stop. Be confident and focus.

 

[heavy-impact]

You can't let concerns about crashing distract you. If I do my eyeballs will start zig zagging as I near the stop. Be confident and focus.

The chuck screws onto my grizzly lathe and then has two locks to keep it secure so there's no chance of it backing off.
My mind and body are not what they used to be so I have to take extra measures or I will screw it up. I do appreciate you sharing your knowledge.
Hopefully Micheal will give a a machining section on this forum where we can share tips, tricks and projects. I feel like more people will buy machines if they have more examples of their use.

 

[lindsey]

+1 on kerosene or light mineral oil on aluminum. It never fails the build occurs at the end of my final cut if I don't use lube.
For threading some materials like cast iron, I'd love the thread in reverse so grit drops out, but I also have a threaded chuck. Not sure what would happen if it unthreaded, nothing good.

 

[KWK]

Not such an issue turning smaller diameters but don't go too big. Tightening your chuck too tight was always a good way to strip the bull gear but now you can buy 3D printed blocks on eBay that jamb the gears and mostly eliminate that risk. South Bend offered instant reversing single phase motors for these lathes and I've never heard of anybody spinning the chuck off but I'm sure it must have happened. Instead of a centrifugal switch on the start windings they have a relay. I have one.
I cut this Acme thread in reverse with no issues. The form bit I ground takes more torque to run than a standard V thread.

And here is that shaft being turned dry making the finish cut getting a very fine finish with HSS

 

[lindsey]

When I first got my lathe I had to make a spindle clamp to hold the back side while we used various forms of leverage to get the chuck off. Is the instant reversing relay actuated by an adjustable limit switch or just manual control? I assume that's only for low speed operation like threading?

 

[GeneT]

Not such an issue turning smaller diameters but don't go too big. Tightening your chuck too tight was always a good way to strip the bull gear but now you can buy 3D printed blocks on eBay that jamb the gears and mostly eliminate that risk. South Bend offered instant reversing single phase motors for these lathes and I've never heard of anybody spinning the chuck off but I'm sure it must have happened. Instead of a centrifugal switch on the start windings they have a relay. I have one.
I cut this Acme thread in reverse with no issues. The form bit I ground takes more torque to run than a standard V thread.
View attachment 445550
And here is that shaft being turned dry making the finish cut getting a very fine finish with HSS
View attachment 445551

Shearing tool in the second photo? Looks like it from the DoC and the "mush" on the cutter. That's one of the rare exceptions where I resort to using a cutter-grinder (actually a single-lip cutter grinder) to get the geometry correct.

It's only fair to mention that the material has a lot to do with it was well. 12L14 will leave a great finish under shoddy conditions, and "home store" 2018 usually isn't going to finish nicely under any condition. I mention this because new folks might grab whatever they have laying around (rebar?) and wonder why they can't get a good finish.

GsT
Edit: mixed edits

 

[KWK]

Shearing tool in the second photo? Looks like it from the DoC and the "mush" on the cutter. That's one of the rare exceptions where I resort to using a cutter-grinder (actually a single-lip cutter grinder) to get the geometry correct.

It's only fair to mention that the material has a lot to do with it was well. 12L14 will leave a great finish under shoddy conditions, and "home store" 2018 usually isn't going to finish nicely under any condition. I mention this because new folks might grab whatever they have laying around (rebar?) and wonder why they can't get a good finish.

GsT
Edit: mixed edits

It's just a general turning tool. Running a low clearance angle to improve finish. 12L14 is lead alloy that gives a real nice finish and breaks up chips. Most everything I make is from scrap metal I scrounged over the years. For gummy steels increase your top and side rake angles.
potentially reduces the life of the edge some but I'm not running production so it's not really relevant. Or just chuck it if it's too bad and grab something else. But I can usually make even hot rolled perform acceptably. The small screw I made above in post #21 is from a scrapped stud.
Only thing I mostly ever used to sharpen my bits is a bench grinder. I have a cutter grinder but loaned it to a friend that was struggling to get angles right and to grind carbide. He wanted to use it so I said ok since I don't use it.

 

[KWK]

When I first got my lathe I had to make a spindle clamp to hold the back side while we used various forms of leverage to get the chuck off. Is the instant reversing relay actuated by an adjustable limit switch or just manual control? I assume that's only for low speed operation like threading?

Most lathes you just put in back gear without pulling the bull gear drive pin. That effectively locks the spindle. But as mentioned above, that's a popular way to strip your back gears or bull gear if it's too tight. My instant reverse is not adiustable. Just throw the drum switch in reverse and back to off off if all you want to do is use it for a magnetic brake from any RPM. Or just use it to reverse without waiting for the centrifugal switch to CLICK. I've rarely used it. I have to admit, I have been known to drag my hand on the chuck to slow it down. Bad habit though.
There are times when I could use instant reverse while threading with a tap or die

 

[heavy-impact]

Only thing I mostly ever used to sharpen my bits is a bench grinder. I have a cutter grinder but loaned it to a friend that was struggling to get angles right and to grind carbide. He wanted to use it so I said ok since I don't use it.

You ever tried a diamond lapidary wheel on your bench grinder for shaping cutters? They remove material easy with less heat than a grinding wheel in my experience. They come in every grit from 60 to 3000 in many shapes and sizes. Around $16

 

[KWK]

Maybe I will, thank you