In article ps.com,
"Harry B. Pye" wrote:

There's a "wavy" washer between the wheel and the left bearing.

I also have a Delta Midi that is about 2 1/2 years old. It has developed an
intermittent screech in the headstock. I don't mean it doesn't always
screech but when it decides to screech the sound is intermittent. Putting it
to a count it is, screech, two, three, screech, two, three. I've used a
screwdriver as a stethoscope on the area of the bearings and heard nothing
unusual. The screech sounds like it is coming from the handwheel!

Two questions:

1. Is there really a wavy washer between the handwheel and the bearing on
the left? My instruction book contradicts itself on this.

2. Is it possible for the outer race of one of the bearings to be spinning
in the casting?

I called Delta and their best advice was to replace the bearings.

Hmmm. My instruction book and parts schematic show the washer between
the handwheel and the left bearing - my lathe has it assembled this way
too. The instructions for taking the spindle out are on p.14,15 of my
book - I can post pics of the pages if anyone wants them. Oh I'll just
do it anyway as it might help Robert with his Jet.

http://users.easystreet.com/onlnlowe/misc/midibearing_p1.JPG 165kb
http://users.easystreet.com/onlnlowe/misc/midibearing_p2.JPG 72kb
(Note: The "Replace Spindle Bearings" section only has 3 steps - none
were cut off.)

Your squealing might be a couple of things which I'd check before
replacing the bearings. Snug down the two set screws on the handwheel
and then snug the set screw on the step pulley. If that doesn't do it,
take all tension off the belt and run the motor to make sure it isn't
coming from there.