Craftsman 12x36 ?'s

[Dfritschlet18]

I have my lathe up and running and have even cranked out a few parts on it. After getting a little time on it I have a few questions....

My lathe has the quick change gearbox, but, even with it set at the lowest travel speed the power feed seems crazy fast. Am I missing something, or is there some trick for slowing it down some more?


It seems to have a fair bit of vibration. The stand I have it mounted on is pretty solid but maybe could maybe be stiffened up some more. Is that the nature of the beast or are there ways to smooth it out a little more


This one is my fault. I tried to slide a piece of 1" through the throat and as you know it wouldn't go. Has anyone opened up the throat on these little guys? An extra .125"-.130" would really make a big difference for what I'm wanting to do with this thing.





Thanks,
Derek

 

[Tony Wells]

I don't suppose you are confusing feed with thread, are you? Rig up a dial indicator to measure just how far the carriage moves with a single revolution of the spindle. Do this with the power off, obviously. If you can't get a feedrate down around 0.002 per spindle revolution, you are doing something wrong. Just what you measure will give us a clue perhaps as to what it is.

The spindle shouldn't be modified, in general. Some are hardened, so it would have to be ground anyway. Opening a spindle up that much probably would be a bad idea in general. They aren't all that thick to begin with, and you would risk a very weak spindle if you opened it up that much.

 

[davidh]

mine was also vibrating quite bad until i installed those linke type drive belts on it. now its dang smooth and pretty quiet. they do have limitations, no question. . .

 

[Dfritschlet18]

Set up the dial indicator. According to the chart the slowest combination of the two levers yields .0042"/rev. With that selection that is exactly what I see on the dial. I would really like to see it down around that .002" mark.


As far as the vibration goes the countershaft pulley "wobbles" somewhere in the neighborhood of .050" side to side. That must be it. Is there a source for these?


Thanks,
Derek

 

[Tony Wells]

Well, 0.0042 seems to me a little coarse for a 12" lathe, but it's possible. I'd want it a little finer myself. Unless you are willing to change the geartrain, or go to an electronic leadscrew, I think you're stuck.

 

[Dfritschlet18]

I was afraid of that. Looks to me like there is enough adjustment that if I could come up with a larger gear to replace the one driven by the slider gear it would help me out some. That part probably doesn't exist though.





Thanks for all the help!