Bad bearings?

[JoeSark]

I just bought another 510, and the previous owner used it quite enthusiastically. I notice some vibration at speeds B through D, which goes away at higher speeds. Is this a symptom of upper bearings going bad, or something else?

[edma194]

Could be bearings but I'd check the speed control mechanism and make sure the sheaves slide freely across the speed range. Possibly the lower sheaves are not closing all the way and the belt is loose at the low end of the range.

If you haven't cleaned and lubed the mechanism now is the time to do so.

[JoeSark]

Thanks, Ed! The sheaves were clean and oiled, but you got me looking closer at the bottom of the machine. Two motor mount bolts were missing. Runs like a dream, now!

[JoeSark]

Thanks, Ed! The sheaves were clean and oiled, but you got me looking closer at the bottom of the machine. Two motor mount bolts were missing. Runs like a dream, now!

[JPG]

Which two?

[JoeSark]

The two that are near the sheave.

[JPG]

The two that are near the sheave.

Well that certainly makes sense.(smaller pulley at slow speeds - lower torque)

Glad the fix was simple!!!

[chapmanruss]

A good reminder to check everything when buying a used tool. Check that all set screws, nuts, bolts, etc. are properly tightened. Clean, wax and lubricate the tool. In this case having missing motor mount screws can easily be missed because of their location.

[JPG]

I cannot imagine any of those 4 screws becoming loose under normal use.