John L. Weatherly wrote:
I had a shaft to rework yesterday in the shop. It is for a walk-behind
concrete saw. I had to build up a worn spot with weld and turn it back
down. The shaft was 1-1/4" and shouldered to 1" for a few inches on each
end. I removed all the parts (washers, spacers, pillowblocks, nuts, etc),
but could not get the pulley off to save my life.

The customer brought his own replacement pillow blocks. He said he tried to
order a new shaft, too, but is no longer available. The new pillow blocks
were 30mm, so I had to turn the whole shaft down in order to slide the new
pillow blocks on from one side.

I have the "non-pulley" end in a 1" 5c collet in the spindle, and the pulley
end on a live center in the tailstock. The lathe is an 11" Logan model
955. The shaft turned just fine until the few inches before the pulley. I
got some pretty rough chatter when I was turning the part that goes inside
the pillow block. It shook the entire machine. I tried different speeds
(270-500 something), different tool height, different feed speeds, but
still the chatter. I also tried a center rest. I could not used the
follower rest because of the proximity to the pulley on the tailstock side.

The thing just barely fit in the lathe. I couldn't put the part in the
other way because the pulley assy. extended over the 1" part, so it
wouldn't slide all the way into the collet.

Any ideas why the chatter?

Thanks!
Tool post grinder?