Shake, Rattle and Roll - Yikes!!

[gtriever]

Well, forget the rattle and roll, but suddenly this lathe has developed a severe shake when trying to drill pen blanks. Here's what I've tried so far:

The cheapie HF drill chuck actually came apart from the MT2 taper shaft, so I replaced the whole thing with a new one - No luck, shake's still there.

Next, I cleaned the inside of the tailstock quill - Nope, shake's still there.

Next, I took the PSI Pen Blank Drilling Chuck apart, cleaned it and reassembled, and cleaned the threads on the headstock - You guessed it, shake's still there.

The pulleys appear to be tight and aligned, the motor is solid in its mounting, and the tailstock quill has a tiny bit of play, but no more than it's always had -

What am I missing here??

 

[greenmtnguy]

Try taking the drive belt completely off and inspect it closely for breaks, splines missing if it has them. Then check the pulleys for crud in the grooves. With the belt off, turn the lathe by hand feeling for a crunch/ bad bearing.

 

[gtriever]

Good advice, and thanks. I found one tiny little chip, not over 1/32, buried between the splines on the belt. Hard to believe that something so small could cause such a big problem, but everything is back to normal.

Thanks again!