# 9a Tailstock Alignment



## dmakseyn (May 1, 2016)

Hi Guys,
Any good ideas on alignment of the tail stock on my SB 9A. I do not have anything like a ground rod with center holes already drilled or I wouldn't have an issue. I know it's off as I can see it when I start a center drill. I fear it may be out vertically which, as I understand it, a real PITA to correct.
Also, how for out is reasonable?


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## Chuck K (May 1, 2016)

A quick and dirty check can be done by inserting dead centers in the spindle and tailstock and look at them with a magnifier.  Not perfect but it will give you an idea of your alignment.


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## Andre (May 1, 2016)

If your lathe has a lot of bed wear, your tailstock offset can change depending on it's position. Mount a bar between centers, take a cut and measure both ends with a micrometer. Once you figure out the needed tailstock adjustments, loosen it slightly and use the adjusting screws to set the tailstock in the needed direction. You can use a dial indicator on a smooth part of the tailstock (such as the tailstock ram or on the center) to measure the offset.


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## Chipper5783 (May 1, 2016)

Like Andre says, test cuts.

http://www.hobby-machinist.com/threads/edge-tailstock-alignment-bar.46364/#post-394592


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## Glenn Brooks (May 2, 2016)

One thing to check is to see if you have any twist in the bed.  If so, level the bed really well with a machinist level and see if that affects your tailstock alignment.  You would benefit from letting the lathe 'settle' if you find serious twist- then checking level again in a week.  I was surprised redently to see how much twist I had in my lathe bed, and it is a big, heavy casting, and how long it takes to remove - but I did take more than 1/4" twist out of my  bed through the leveling process - and it cleaned up my tailstock alignment problems really well.

Conversely, if your bed is dead level and you still have vertical misalignment, Iam told it is possible to improve the alignment by purposely imparting twist in the bed, to cause the tailstock to raise up to the axis of the headstock.  Sounds like a nightmare process, but picture aligning a boat shaft with an engine.  This is exactly the same process- the adjusting screws can push the tailstock through a circular arc to any position you wish (along the radius).


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