This is my first post here but I have been reading a ton of old posts trying to figure out a few things. I picked up what looks like a 1946 9 B from an auction guy who had it sitting in boxes in his wharehouse for years. It was a bit of a gamble but I figured out how to put it together. The lathe ways look like it has had very little use.
I picked up a real SB thread dial from Ebay. The dial gear has 32 teeth. My lead screw is 8 tpi. My stud gear is 32 teeth as is the screw gear. I am trying to cut 8 tpi threads on 1" A36. When I thread using the dial each pass is slightly off to the left. After a few passes I have a fine threaded (sort of) mess.
When I thread using reverse and leave the half nuts engaged the threads turn out perfectly.
The thread dial appears to fully engage and the gear does not look worn out.
At this point I am thinking it has to be either the thread dial gear is in fact too worn or my half nuts are not engaging identically each time. Due to the lack of wear on the lathe overall I suspect the issue is the thread dial gear. Does anyone have any other ideas as to what is going wrong? Does anyone know of a source for a steel replacement thread dial gear?
Thanks
Dave
I picked up a real SB thread dial from Ebay. The dial gear has 32 teeth. My lead screw is 8 tpi. My stud gear is 32 teeth as is the screw gear. I am trying to cut 8 tpi threads on 1" A36. When I thread using the dial each pass is slightly off to the left. After a few passes I have a fine threaded (sort of) mess.
When I thread using reverse and leave the half nuts engaged the threads turn out perfectly.
The thread dial appears to fully engage and the gear does not look worn out.
At this point I am thinking it has to be either the thread dial gear is in fact too worn or my half nuts are not engaging identically each time. Due to the lack of wear on the lathe overall I suspect the issue is the thread dial gear. Does anyone have any other ideas as to what is going wrong? Does anyone know of a source for a steel replacement thread dial gear?
Thanks
Dave