Cross Slide Stop for threading on my 13" South Bend?

Hello,
I am struggling to return the cross slide back to the zero point in order to feed the compound in for another pass when threading.
I have a single gear box (1941) 13" South Bend. It has the small dials with some backlash like all lathes.
If I could dial back the cross slide to clear the threads, move the saddle back to the starting point then move in the cross slide to a positive point each and every time, then I could feed the compound with confidence.
I am looking for the locking device, guide, stop or whatever will perform the intended cross slide location.
Thank you for your help and I apologize for my ignorance, I don't have very much experience.
Jeff
 
Is it the backlash that is making it hard for you to do? If so , if you turn the handle to the right to get to your point of cutting then after you run the cut you can turn the handle to the left to back the tool out. When you move the tool back to the starting point make sure you turn the handle to the right again which will take the backlash out again and you should be able to go back to your first point of cut and add the extra to cut in further. Hope i explained it well.... Warren
 
Cross slide is used to retract the compound slide. Compound slide is used to cut the thread depth (not all at once pls). Snug the cross slide gibs, if the cross slide & compound dials has a set screw, use it to hold your zero. Fenner, Abom79 & Oxtools have excellent threading vids. No worries, we all have to start somewhere.
 
If the front face of your cross slide has a tapped hole in it, you can make a screw to fit it with a threaded collar outboard of it and a stop bar to fit the dovetail of the male dovetail that clamps to the dovetail via a detachable dovetail on one side with a bolt through from the end to clamp it up and a hole through the center to accommodate the threaded rod attached to the cross slide, this is a stop to limit the amount of travel of the cross slide when threading; most lathes had a device like this, but most got lost (mine did). They would be an easy thing to make. I will see if I can get a picture of one and post it later. Having lots of backlash makes it a bit harder to back out and keep up with where you started, especially with very coarse threads are being cut, keeping track of the number of turns necessary to clear the threads.
 
You know, I have not analyzed it, I made an assumption. I make a cut, make one full revolution to the left, move saddle, return the cross slide back one full turn to the right. By this action, I assumed I would not be in the same spot taking the backlash into consideration.
So you are saying it works both ways? One full turn out and back in will get you back to the same exact place?
Another study on my part, when I move the compound in (set at 29.5) I am moving the compound to the to the opposite side of the pressure of the screw. Meaning when I make a cut, the tool is pushed back to the opposite side of the screw.
Am I making any sense?
Regarding gibs, I have them as snug as I can before binding, the screws and brass are new.
I have watched plenty of videos, Mr. Pete, Tom's Techniques, Oxtools etc. The videos are extremely helpfull.
My threads are of good quality, clean cuts, I grind HSS, the thread gauge works flawlessly as long as I go back to the same number each time.
I am getting close, I just struggle with the exact depth I am attempting to cut. I can move in .015 and I only make a very light cut. Next time, I move in .015 and the cut is a bit too deep??
Practice and observation is needed on my part. I'll get it.
Thanks guys.
 
If the front face of your cross slide has a tapped hole in it, you can make a screw to fit it with a threaded collar outboard of it and a stop bar to fit the dovetail of the male dovetail that clamps to the dovetail via a detachable dovetail on one side with a bolt through from the end to clamp it up and a hole through the center to accommodate the threaded rod attached to the cross slide, this is a stop to limit the amount of travel of the cross slide when threading; most lathes had a device like this, but most got lost (mine did). They would be an easy thing to make. I will see if I can get a picture of one and post it later. Having lots of backlash makes it a bit harder to back out and keep up with where you started, especially with very coarse threads are being cut, keeping track of the number of turns necessary to clear the threads.

I was hoping there was something like what you are describing.
Thank you.
 
Here are some pics of a cross slide stop for threading the first pics are of the dovetail type, the last two are of another type where the stop rod is at the front left hand of the cross slide and another tapped hole on the front left of the carriage just below the cross slide, which mounts a slotted link that the stop rod engages with a adjustable stop nut, the link swings out of the way when not in use.

wood lathe parts and lathe stop 004.JPG

wood lathe parts and lathe stop 005.JPG

wood lathe parts and lathe stop 006.JPG

wood lathe parts and lathe stop 007.JPG
 
You know, I have not analyzed it, I made an assumption. I make a cut, make one full revolution to the left, move saddle, return the cross slide back one full turn to the right. By this action, I assumed I would not be in the same spot taking the backlash into consideration.
So you are saying it works both ways? One full turn out and back in will get you back to the same exact place?


You can't base it on turns if you want precision. You need to use the dials or an indicator. Set the cross slide where you want it, zero the dials or indicator. Now you can get back where you were to the limits of the graduations. Note that for the dials to be accurate, you need to move only in the same direction the entire time. You can't spin back to get there, you have to take up the backlash, move out a little, then do the same going the other way and stop on the mark.

One thing that might come up with a lot of backlash is if you need more than one turn to take it up. Then you have to remember to move 2 turns + go to the mark. You could practice with a dial indicator on the cross slide so you can see exactly where you are the whole time.

There's nothing wrong with building a stop as well, but make sure you know how to hit the right spots using the dials.

For depth, since you're using the compound you are at an angle and the graduations don't tell you exactly how much you're cutting. I believe there is a calculation to figure it out, but just use a gauge, or if you want to-spec threads, a thread mic or measurement wires. If the issue is more about depth of cut, you might have deflection in play as well.
 
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