Spindle 'Slack'

[nat_wheatley]

I've always had a fair amount of 'play' in my machine, and have never really been able to track down the source, everything seems tight. I noticed today that I can grab the chuck of my spindle (4hp), and wiggle it back and forth, getting a small 'tap' each time it hits the insides of the housing. Is this normal? Thanks.

[carlcnc]

Nat
that surely isn't normal.
you mean the chuck rattles around in the spindle?

means bad bearings, really bad bearings. hopefully the top ones
as they are a lot less pricey than bottom pair
It should also show up as excessive noise.

Carl

[nat_wheatley]

It's whatever 'shaft' that the chuck is attached to that is moving around. Not sure of the correct terminology...

[cabnet636]

if you have slack (enough to notice) then the spindle should be screaming with vibaration

[nat_wheatley]

It's not a piercing scream, but a high pitched somewhat rough 'hum' if that makes any sense. Not that that's good either. Am I remembering correctly that you typically shouldn't hear the spindle when it on/not cutting?

It hasn't happened overnight, I've noticed, over time, progressively more 'play' in the cuts.

Spindle is model AT/MT1073-140

[nat_wheatley]

Having read some of the older posts, I may attempt to replace the upper bearings, and see if that helps.

Bad idea? Tips/special tools needed? Thanks.

[benchmench]

HSD considers the spindles expendable since it would cost around $1000 for them to repair it. A new HSD AT/MT1073-140 from HSD USA runs about $1500.