On 2/12/2019 7:05 PM, DoN. Nichols wrote:
On 2019-02-12, Gunner Asch wrote:
On Mon, 4 Feb 2019 16:59:16 -0600, Terry Coombs
wrote:

Â* I finally figured out that the reason the drill chuck that came with
my bench top milling machine was so wobbly is the mandrel . The JT taper
is all weird , too loose in the bottom of the hole
[ ... ]

Frankly..unless you like farting around..order a new one. Saves you
time and likely..money.
One thing to consider -- before your (now snipped) attempt to
re-turn the taper -- you should have checked what the taper *really*
was. Note that there are both the more common Jacobs tapers (JT?), and
some for German tapers (B?? series), which are not necessarily
interchangeable with Jacobs tapers. There may even be other tapers for
chucks.

Just to be sure -- get the chuck and the arbor at the same time,
so you are sure that both are Jabobs tapers.

Enjoy,
DoN.

The chuck/arbor in question came with my mill . And the original chuck
and the replacement - I bought 2 from Iggy some years ago - are
identical in dimensions . Both fit a known 33JT taper . The new mandrel
came a few days ago , mounted the chuck and tried it out in the mill and
it runs true to the eye . I haven't put a dial indicator on it yet , but
it sure beats what I had . The original chuck is now on my small drill
press , and it runs true too . The original mandrel is in the box for a
future project , TBD at a later date .

--
Snag
Yes , I'm old
and crochety - and armed .
Get outta my woods !