Thread: Lathe Adjustment

Iteach my men to that, but for another reason. We cut a lot of large diameter, course pitch threads. A lot of 4 tpi, and occasionally a 2 tpi. One of the problems with cutting large threads, (especially in the low carbon steels we use), is the shavings tend to meet in the middle, clog, and weld to the insert, causing the thread to get real ugly, not to mentioned breaking the inserts. The way I teach the men to cut threads is rough out about...

After 20 minutes, the heat from my bearings is comfortable to the touch, not too much. Maybe I'll tighten them up a bit and run it. Thanks Dennis & Jackie for the information, as always, it's appreciated.

Jackie: It helps to diminish lead error at the start of a thread when the load is developing. The gear train is loaded with the weight of the mass but the tool has yet to add its' own, additional resistance. Usual result is a bit of drunken thread at the start. It is more apparent on lighter machines with smaller amount of mass in the carraige/drive train.

Quote: Originally Posted by Alan Warner Jackie: It helps to diminish lead error at the start of a thread when the load is developing. The gear train is loaded with the weight of the mass but the tool has yet to add its' own, additional resistance. Usual result is a bit of drunken thread at the start. It is more apparent on lighter machines with smaller amount of mass in the carraige/drive train. Alan, for lathes which do not have lead...

Quote: Originally Posted by jackie schmidt Iteach my men to that, but for another reason. We cut a lot of large diameter, course pitch threads. A lot of 4 tpi, and occasionally a 2 tpi. One of the problems with cutting large threads, (especially in the low carbon steels we use), is the shavings tend to meet in the middle, clog, and weld to the insert, causing the thread to get real ugly, not to mentioned breaking the inserts. The way I teach...

My 1971 11inch Rockwell has a large tapered Timken bearing... and a grease nipple under the top cover. After greasing it and running for a while and it heats up, excess grease is forced out the front, between the headstock and the chuck and makes a mess for a while... it does not seem to matter if it is cold or hot I don't seem to get any movement I can measure. It gets quite warm after an hour or so...

Quote: Originally Posted by Alan Warner Jackie: It helps to diminish lead error at the start of a thread when the load is developing. The gear train is loaded with the weight of the mass but the tool has yet to add its' own, additional resistance. Usual result is a bit of drunken thread at the start. It is more apparent on lighter machines with smaller amount of mass in the carraige/drive train. I never thought of this. I'm checking...

of your machine. A sort of show and tell!! How old is this machine? Are you using the right type of oil for the spindle? Their are some who dump any old oil in their. I love South Bends. I have a 1964 16" toolroom. Took a shim out about a month ago. Those Bronze bearing are expensive. Almost $400 for the front and $385.00 for the back or small bearing