Need recommendations on sb9a headstock wear

[BrianVedack]

My SB9A has some heavy side to side spindle bore wear. I've de-shimmed it and removed the up and down wear but the side to side is still there. I'm talking .010". I could use some ideas on how to correct this. I've considered boring out the headstock and using needle bearings. Not sure if the spindle is hardened enough for direct contact needle bearings or may need an inner race needle bearing. Either way if anybody has better suggestions I'm all ears....er...letters.

 

[Eddyde]

Hum, that's strange, Are you measuring the play directly to the spindle or to the chuck?

 

[markba633csi]

When you say side to side you mean toward you and away from you correct? Does your machine have replaceable bronze bearing shells?
Have you inspected the spindle bearing surfaces?

 

[Jim F]

Buy my C model, headstocks should be the same.

 

[woodchucker]

I have considered boring the head out and adding bronze sleeves. I believe the 10k or heavy 10 has them.
Not certain.

But I was advised that I should look for a new head.
so just dealing with it. We'll see.

I'll be watching this thread.

 

[BrianVedack]

Hum, that's strange, Are you measuring the play directly to the spindle or to the chuck?

From the spindle

When you say side to side you mean toward you and away from you correct? Does your machine have replaceable bronze bearing shells?
Have you inspected the spindle bearing surfaces?

Yes. correct. I removed the belt and would get the play toward the motor. It does not have bronze bearings and I have looked at the surface when I restored it. It didnt look bad and didnt think of measuring it at the time.

 

[markba633csi]

When restoring a SB this is probably the most important thing to check, besides the condition of the ways
If your spindle runs directly in the cast iron head, then headstock replacement is really the easiest option. I suppose a bearing retrofit is possible
but I have never seen one
The other option would be to have the spindle bearing surfaces plated up or plasma-sprayed and then re-ground, and have the headstock bore reconditioned

 

[gard]

I would love to see a bearing retrofit for a SB. I would think a taper bearing would be better than needle bearings, the spindle already has a threaded nut on the end for adjustment. Not sure how to bore it out so it would be in alignment with the bed. Seems like it's hard to evaluate the condition of some of the used heads on the bay.
I suspect if the bore was oversize by 0.001 or 0.002" it might be usable with a thicker oil? If you have 0.010" of movement, not sure if there is an easy fix. Do you have the segmented cast iron bearing?

 

[woodchucker]

I would love to see a bearing retrofit for a SB. I would think a taper bearing would be better than needle bearings, the spindle already has a threaded nut on the end for adjustment. Not sure how to bore it out so it would be in alignment with the bed. Seems like it's hard to evaluate the condition of some of the used heads on the bay.
I suspect if the bore was oversize by 0.001 or 0.002" it might be usable with a thicker oil? If you have 0.010" of movement, not sure if there is an easy fix. Do you have the segmented cast iron bearing?

Not going to happen. It would require major machining. There's just not enough of a need, or of us willing to pay the price.
Better to get a spindle with out a screw on chuck.

 

[BrianVedack]

Trying to find a bearing that will fit the spindle without modifying it is a challenge. What would be the top choice for bushing material if one was to make one?