Max Safe Speed For My Old 1926 Southbend

[refinery Mike]

I got an old south bend 9-20 with bronze bearings, what is the top speed that it can safely be continuously run.

 

[TommyD]

If it spins fine, gets lubrication and the spindle is tight in the bearings it should be able to run as fast as the pulleys on it allows.

 

[bleonard]

1000 RPM

 

[pineyfolks]

What bronze?

 

[TommyD]

Most probably the spindle bearings, headstock and tail of the spindle. The Southbends I used would have to have attention paid to them on occassion. We had shims between the bronze bearings on the headstock and when the bearing became worn, we would remove a shim and use hi-spot to see how the spindle was rubbing on the spindle and scrape accordingly.

We would run our tool bits upside down and reverse spindle rotation to put the cutting forces DOWN onto the headstock casting bearing to stop tool chatter until we could fix the looseness of the bearing to spindle.