Unisaw bullet motor starting problem

[Bill Dufour]

The bearing grease is more then 70 years old so it should be replaced. far easier to replace the entire bearing rather then try to pull the shields and reinstall them. Is the vee belt 70 years old as well? Might be a good time to replace it while things are apart. As I remember there are two arbors the older one used special bearing with extended inner races and maybe a spacer.
The newer version the arbor is bigger diameter in the middle so the bearing can not get too close together. Or maybe the spacer is just a bit longer so regular bearings work.
Bill D.

[Zachary Hoyt]

I ordered the old style arbor bearings this morning, assuming they'll be correct. If not I should be able to get the regular ones through NAPA in town faster, if I take the arbor apart and find it's not the origina typel. The V belts look nearly new, though I have been running them for a while and they were on the saw when I bought it. They're the greenish kind of heavy duty rubber and there are two instead of three but that seems to be plenty for the size of the motor.

I took the oval covers off at the end of the motor and looked in, and I would say the motor looks like it was rebuilt not too long ago. The windings are blackish with age, but the wire going to one of the brushes was visible and it looks as shiny as new, and the commutator is fairly clean. Also the paint on the gray cylinder part of the motor is a different color gray than the cabinet, and looks newer. I can't feel any end or axial play in the bearings and the motor runs very smoothly and quietly, so I will continue running it. If anything changes I will re-evaluate, or if there is a catastrophic failure I will certainly post about it here right away.

[John TenEyck]

That's a logical approach, but 54 seconds for the motor to stop spinning strongly suggests the grease in the bearings has dried out. Keep your ears tuned.

John

[John Lanciani]

54 seconds is about 44 seconds too long. Replace the bearings before you do permanent damage to the motor.

[Bill Dufour]

When those motor bearings freeze up they may scour the endbell bores beyond repair or they may scar the arbor shaft the same way. Yes there is spray welding and remachineing, but a new motor will be cheaper.
That galling and friction welding can occur in just a few seconds under power.
Bill D