billfromthebruce
Plastic
- Joined
- Jul 21, 2017
So , this is my first post but I have read different forums over some time.
Here is my situation.
I have an old 10 inch SB quick change lathe that I have had for a lot of years. Last week while trying my best to turn a piece with a .0005 tolerance and not having great luck I decided to check the head stock bearing adjustments as per SB bulletin H4 and found about .015 play. This being way too much and not being able to figure out how I never noticed it in the past I proceeded to tear it down. What I found surprised me. Whoever had it apart last did not have the H4 bulletin to put it together.
The brass/bronze spreaders that are dovetailed into the top of the bearing were installed on top of the bronze bearing and not fitted into the dovetail. As a result the top of the bearing was indented where the spreaders were pushed down into the slot.The spreaders are not really damaged but the lip of the bearing is deformed a bit. I was able the get the spreaders into there spot and then attempted to fit the required shims to get the proper .001 clearance. However I had to put a whole pile of shims in both bearings to get it to turn freely. When I got to this point I could visibly see the shaft move when I put a bar in the taper of the spindle and lifted. I suspect that somehow the spreaders are causing a binding on the shaft requiring all those shims.
So I am looking for solutions and suggestions. I was thinking of assembling the bearings without the spreaders and trying to see what shims were required and then installing the spreaders. I suspect if this is the case then I would have to file down the spreaders to prevent binding.
But before I destroy a perfectly good part I am asking for your advice. I really don't want to try and get a set of bearings to start all over new as I am up in Canada and would have to find someplace to get them.
Please help and sorry for being long winded but I wanted to put all the information I had on the table.
Bill
Here is my situation.
I have an old 10 inch SB quick change lathe that I have had for a lot of years. Last week while trying my best to turn a piece with a .0005 tolerance and not having great luck I decided to check the head stock bearing adjustments as per SB bulletin H4 and found about .015 play. This being way too much and not being able to figure out how I never noticed it in the past I proceeded to tear it down. What I found surprised me. Whoever had it apart last did not have the H4 bulletin to put it together.
The brass/bronze spreaders that are dovetailed into the top of the bearing were installed on top of the bronze bearing and not fitted into the dovetail. As a result the top of the bearing was indented where the spreaders were pushed down into the slot.The spreaders are not really damaged but the lip of the bearing is deformed a bit. I was able the get the spreaders into there spot and then attempted to fit the required shims to get the proper .001 clearance. However I had to put a whole pile of shims in both bearings to get it to turn freely. When I got to this point I could visibly see the shaft move when I put a bar in the taper of the spindle and lifted. I suspect that somehow the spreaders are causing a binding on the shaft requiring all those shims.
So I am looking for solutions and suggestions. I was thinking of assembling the bearings without the spreaders and trying to see what shims were required and then installing the spreaders. I suspect if this is the case then I would have to file down the spreaders to prevent binding.
But before I destroy a perfectly good part I am asking for your advice. I really don't want to try and get a set of bearings to start all over new as I am up in Canada and would have to find someplace to get them.
Please help and sorry for being long winded but I wanted to put all the information I had on the table.
Bill
