What you said will help but try my suggestion about od lapping the shaft it will make it more concentric than just stoning . Maybe you don't follow what i'am saying but i have rebuilt high speed spindles where i use to work and this is a cheap fix. Like i stated before it is not a precision grinder which i would not recommend this presider.
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Spindle Binding When Trying To Bring Tolerance Into Spec.
- Thread starter jbmauser
- Start date
- Joined
- Dec 8, 2013
- Messages
- 2,651
I'd inspect the bore before concluding that it is badly damaged.
JH, it is scored as well, how badly damaged I don't have any reference from mirror smooth to what... do you know what I mean. I have no way of saying poor, good, horrible. I will say the lathe functioned with the bent shaft but she looses a lot of oil. the play in the rear was about 7 thou. less with the original scored shaft. I do not work in high precision. I am only going to tinker with this and make some bits. This is a hobby for an inquisitive mind.
- Joined
- Jan 22, 2011
- Messages
- 8,031
Then you're probably stressing too much about it. Overall, as long as it's not really banging around, and doesn't get hot....you should be good to go. Even with the minor tight spot, as long as you are generous with the oil, you should be fine. Save your money and worry for your next lathe.
I don't think you ever stated whether you are running in straight iron or in bronze bushings though. If so, I missed it.
I don't think you ever stated whether you are running in straight iron or in bronze bushings though. If so, I missed it.
One of the photos shows what looks like a punch mark so something got it.
But the good news is it really does NOT look that bad.
If yiu have a wood lathe that will allow yiu to spin it between centers yiu can polish it up.
First you need to carefully clean it to remove anything dug in.
Next is get a like new flat fine file and very lightly slide it over the nick in the photo.
Next is paint it with a felt tip pen and let it dry well.
Find a flat stone and gently rub the area to now check for high spots.
Low spots or holes left from nicks just hold oil.
Once all high spots are gone spin it up and give it a polish.
Clean up bushings in the caps then repaint with felt tip pen and assemble loosely and spin spindle and tear down to see how the interface between the parts look.
Again focus on high spots.
Assemble and retest.
When it feels good paint it again and tighten everything and turn spindle just one turn and tear down to check again.
Polish as needed then correct shims as needed.
If you are missing any yiu can make them out of soda cans.
Cut with a good scisors.
Sent from my SAMSUNG-SGH-I337Z using Tapatalk
But the good news is it really does NOT look that bad.
If yiu have a wood lathe that will allow yiu to spin it between centers yiu can polish it up.
First you need to carefully clean it to remove anything dug in.
Next is get a like new flat fine file and very lightly slide it over the nick in the photo.
Next is paint it with a felt tip pen and let it dry well.
Find a flat stone and gently rub the area to now check for high spots.
Low spots or holes left from nicks just hold oil.
Once all high spots are gone spin it up and give it a polish.
Clean up bushings in the caps then repaint with felt tip pen and assemble loosely and spin spindle and tear down to see how the interface between the parts look.
Again focus on high spots.
Assemble and retest.
When it feels good paint it again and tighten everything and turn spindle just one turn and tear down to check again.
Polish as needed then correct shims as needed.
If you are missing any yiu can make them out of soda cans.
Cut with a good scisors.
Sent from my SAMSUNG-SGH-I337Z using Tapatalk
Lots of info to digest. I took my spindle to a friend who has some serious machines and the ability to take much better measurements to see the most accurate condition of the "bent" spindle. To all of you who spoke of bearing caps etc. this lathe has no bearing caps the spindle rides in the cast iron headstock with only a single bolt and slit which contains spacers to adjust for clearance. This is a South Bend model C workshop lathe from the early 40's. Any damage to the casting from the scored spindle in the images I posted remain no mater what improvement is made to the spindle.
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Cast iron bushing explains the pock mark in the photo.
That is one reason to not use air to clean as it may have got a chunk of something in a gap then sucked it in.
So focus only on locating high spots then polish it up but a mirror finish is not the goal here as it would require too much material removal.
The goal is to remove any rough edges that act as cutting edges.
Inspect the bushings with a magnifying lens as they can hold nasties between the ridges as well as in the surface.
Use 600 grit with solvent or steel wool to avoid leaving abrasives from the paper behind.
Sent from my SAMSUNG-SGH-I337Z using Tapatalk
That is one reason to not use air to clean as it may have got a chunk of something in a gap then sucked it in.
So focus only on locating high spots then polish it up but a mirror finish is not the goal here as it would require too much material removal.
The goal is to remove any rough edges that act as cutting edges.
Inspect the bushings with a magnifying lens as they can hold nasties between the ridges as well as in the surface.
Use 600 grit with solvent or steel wool to avoid leaving abrasives from the paper behind.
Sent from my SAMSUNG-SGH-I337Z using Tapatalk
Thanks again for all info. As to polishing. Let me restate my situation as threads tend to wander. I have 2 spindles for my lathe, one pictured is the original and it is scored and galled. The second came from a beat up 9 in. lathe that I parted out and kept the spindle as it only had a few scores on the spindle. That is the spindle I had put into my lathe as it was a cleaner surface but turns out it is bent. I found that out when I tried to bring the spindle into tolerance adjusting the headstock shims. I can work on either spindle to improve their condition or I can buy another on eBay for under $100 that is without score marks and hopefully is true. The condition of the scored spindle reflects the condition of the headstock bearing surface.
Recap of info I have received is to improve the scored spindle I can file (which I had done to remove any fused cast iron bits) stone and polish. For the bent spindle I should have it honed by an engine shop. That would bring it to concentric with the chuck end of the spindle and then adjust the shims to bring it into spec.
Lastly, my concern is that any spindle improvement or replacement will still be held in a headstock iron bushing that is scored with no economical improvement. And the lathe will run with either flawed shaft, albeit with a lot of oil consumption. A suggestion to use a heavier oil leaves me to wonder if it will wick through felts but that is another thread for anther time. For now I wait on my friend to see the exact condition of the bent shaft.
Recap of info I have received is to improve the scored spindle I can file (which I had done to remove any fused cast iron bits) stone and polish. For the bent spindle I should have it honed by an engine shop. That would bring it to concentric with the chuck end of the spindle and then adjust the shims to bring it into spec.
Lastly, my concern is that any spindle improvement or replacement will still be held in a headstock iron bushing that is scored with no economical improvement. And the lathe will run with either flawed shaft, albeit with a lot of oil consumption. A suggestion to use a heavier oil leaves me to wonder if it will wick through felts but that is another thread for anther time. For now I wait on my friend to see the exact condition of the bent shaft.