Trueing Spindle Bore

I'm with the rest of the bunch here, WHY? BUT......I would make up a line boring bar. A bushing for each end and the tool bit in the center, Feed with the drill chuck in the tail stock.
 
Frankly, I wouldn't do it. If it interfered with work, maybe.....but not likely.Too much at stake and too many places for things to go wrong. It's your lathe, so you do what you will. But I wouldn't.:)
 
Unless you have 1.3" material through the headstock your probably not going to have a problem, HOWEVER.....make sure that MT5 taper wasn't machined crooked! If that is the case, contact your manufacturer. If it's behind the taper thats off, you could machine it but be careful.
 
What kind of a lathe is it? Who made it? If an Import, the steel they use is iffy at best. Probably full of internall stresses. And you will weaken it a little. I think you will open up a can of worms. Use the lathe as it should be used, have some fun with it. In a few weeks you will have forgotten all about it. Some collet drawbars do reference the ID of the spindle, but usually only at the last 1” or so at the back. You could clean up that portion of the ID I guess for a draw bar and other accessory items that would reference the spindle ID. Other than that, just don’t look at it, use it and have fun!
 
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I would be with the others. If the MT5 taper is fine, leave the rest of the bore alone.
 
Tozguy said:
Fletch, you are right, there is a MT5 taper for the first 5 inches in from the spindle nose. The spindle bore starts to be restricted at the 5.5'' mark. The MT5 taper is concentric to the spindle axis :) so it won't get cut.
After that the bore is 1.490'' but not concentric with the spindle axis, by how much is a good question, maybe in the neighbourhood of .025''.
Dan, you are right too, for a normal person this is a perfect case of 'if it ain't broke don't fix'.
But I have a few ideas about how to go about boring the spindle that I am itching to try. Wish me luck, it might take a boatload of it to pull this off.
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its not broke now but it sure might be when you get thru. leave it alone!!!
 
Oh my Ken - go to a race for the crashed, but leave the poor lathe alone!
 
Tozguy said:
Ever since I discovered that the spindle bore on my lathe is eccentric I can't sleep.
I want to turn it true but was wondering if it might change the stress in the spindle and warp it (or produce some other unwanted result).
Leaving it alone is not an option unless the guys in white coats get me first.
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Tozguy said:
Ever since I discovered that the spindle bore on my lathe is eccentric I can't sleep.
I want to turn it true but was wondering if it might change the stress in the spindle and warp it (or produce some other unwanted result).
Leaving it alone is not an option unless the guys in white coats get me first.
Click to expand...
 
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