How to avoid running into my chuck on power feed.

dbb-the-bruce said:
Southbend has a clutch in the carriage drive that generally saves it from damage but you shouldn't rely on it as your first choice.
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Perhaps my dry and sarcastic sense of humor didn't really translate to a quick Saturday morning response, My Bad.

David R8's response reminded me that I often to the same

DavidR8 said:
On my 10K I did some experiments to get a feel for how many turns of the clutch knob achieved engaged the clutch.
When I’m doing an op that runs close to the chuck I have my hand on the clutch knob and disengage it when/where I want the carriage to stop.
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The original posters question is specifically in regards to his SouthBend 10K - which has (to my knowledge) the exact same controls as my 9A

The clutch on for the power feed on these lathes is engaged / disengaged with the twist of a knob on the carriage, that's it, that's all you got other than disengaging the drive belt. Additionally, how tight the clutch holds is controlled by how hard you twist the knob.

If you don't crank the hell out of the clutch knob, it will be the first point in the drive train to slip IF you happen to screw up and hit the stop or something else (going toward the tail stock, you can bind up the carriage on the tail stock). There is no way to "trip the power feed" on these lathes. (correct me if I'm wrong).

To be clear, you should never CHOOSE to use a stop as the way to stop carriage motion. I will often set one up to prevent me from doing something stupid, like manually cranking the carriage into the chuck by hand when working close to the headstock. When learning to use my lathe there were probably a couple of occasions where I screwed up and ran the carriage into the stop - the clutch slipped (I didn't over crank it) and / or the belt slipped off the headstock. My lathe is running as good as it did when I purchased it.

These SouthBend lathes are old-school and very well thought out and refined designs for manual turning with HSS bits. The engineers built them to survive common mistakes. (I'm not an authority, that's my opinion).

@twooldvolvos - You've got a great lathe and you are approaching using it with the right attitude.
Enjoy
 
To Jim F: you are correct on Joe Pie. Bad example. At school, we did not run the lathe in reverse, just the lead screw. Should have made this clearer.
 
silence dogood said:
To Jim F: you are correct on Joe Pie. Bad example. At school, we did not run the lathe in reverse, just the lead screw. Should have made this clearer.
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I was wondering why SB even put a reverse switch on their small lathes, then I remembered about my collet adaptor.
 
First off a carriage stop really doesn't stop the carriage at least on my lathe. The carriage will push it no matter how tight I clamp it to the ways.

This is what I do. I set the carriage stop. As the carriage approaches the stop I move a piece of paper back and forth with my left hand between the carriage and the carriage stop. My right hand is on the half nut release lever. When the piece of paper catches I release the half nuts. It really doesn't seem to be a big deal. It does require paying attention to what you are doing. But then everything you do on a manual lathe requires paying attention to what you are doing.

IMG_3645.JPG
 
You are talking about something completely different - using the lead screw / half nuts, typically only used for threading. And yes, the stop is not going to help at all if you have engaged the half nuts on the lead screw.

We may very well be talking about different revisions of the same lathe - My lathe has a keyway in the lead screw that drives the carriage (X or Y) that is independent of using the lead screw to drive the carriage when cutting threads. Perhaps older lathes don't have this.

And yes - using the lever on the carriage to engage the half nuts on the lead screw, cutting threads to a shoulder is another level of anxiety!
 
dbb-the-bruce said:
You are talking about something completely different - using the lead screw / half nuts, typically only used for threading. And yes, the stop is not going to help at all if you have engaged the half nuts on the lead screw.

We may very well be talking about different revisions of the same lathe - My lathe has a keyway in the lead screw that drives the carriage (X or Y) that is independent of using the lead screw to drive the carriage when cutting threads. Perhaps older lathes don't have this.

And yes - using the lever on the carriage to engage the half nuts on the lead screw, cutting threads to a shoulder is another level of anxiety!
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Some SB lathes only have the half nuts for z axis feed, like my 9C.
I think small Atlas are the same.
 
Jim F said:
Some SB lathes only have the half nuts for z axis feed, like my 9C.
I think small Atlas are the same.
Click to expand...
Interesting, I always assumed that the 9C were for large production situations. IE. you a have a room full of lathes that are setup to make specific parts. I can see how in a situation like that you could expect the operators to use just the half nut lever to control the carriage. Also, you would need to change gears out to change the feed?

Glad I have a toolroom lathe.
 
dbb-the-bruce said:
Interesting, I always assumed that the 9C were for large production situations. IE. you a have a room full of lathes that are setup to make specific parts. I can see how in a situation like that you could expect the operators to use just the half nut lever to control the carriage. Also, you would need to change gears out to change the feed?

Glad I have a toolroom lathe.
Click to expand...
C models were for mechanic and home shops, not for production.
Yes, the change gears control the power feed rate,also.
my 9C.
 

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