Subject: Re: Beginner Questions

From: [email-masked] (Jonathan M. Elson)
Date: 14 Dec 1996 05:14:39 GMT

[email-masked] wrote:
: I have recently purchased the 2hp mill/drill from Enco.  Is seems to
: be a pretty good machine for learning.  I have a few questions that
: continue to perplex me.

: -  What is a good procedure for centering an 8" rotary table?

If you have a dial indicator, or better yet a dial test indicator,
and the outside diameter of the table top is true (some cheapies aren't)
then you put the indicator holder in the spindle and sweep it around
the table top, adjusting X-Y table position until the indicator doesn't
change reading as it sweeps around the rotary table top.  If the OD
of your rotary table is NOT true, you might want to use a grinding wheel
in the mill spindle to cut a lip about .100 wide that is true to the
center.  You would do this by rotating the rotary table and advancing
the wheel into the table until it makes a continuous ground surface all
the way around the circumference.  (You don't want to grind the whole side
of the table because it would take off the degree markings.)

: - How crucial is leveling the machine?  I have it on Enco's mill drill
: stand which I am certain must be unlevel.

Some people say the machine will never be accurate unless it is perfectly
level.  On a machine like this, it is not likely to make much difference.
But, if your table is level, then you can level any odd part in a vise,
and know IT is now parallel to the table. When clamping odd parts, like
shafts, in a vise, a level can get it true when parallels, calipers and
other things may not fit for some reason.

: Thanks for the help and any other comments on this machine would 
: be helpful.

Hmm, you'd better check the leadscrews.  Some of their import machines
have metric screws with obscure markings like .002"/div .05mm/div
Well, .002" is not equal to .05mm!  On the small scale, you'd never
notice, but on the large scale, over a few inches, the error really
creeps up.

---

From: [email-masked]
Date: Fri, 13 Dec 1996 19:15:08 GMT

I have recently purchased the 2hp mill/drill from Enco.  Is seems to
be a pretty good machine for learning.  I have a few questions that
continue to perplex me.

-  What is a good procedure for centering an 8" rotary table?

- How crucial is leveling the machine?  I have it on Enco's mill drill
stand which I am certain must be unlevel.

Thanks for the help and any other comments on this machine would 
be helpful.

---

From: dennis j brown <[email-masked]>
Date: Sun, 15 Dec 1996 22:37:03 -0600

> Thanks for the help and any other comments on this machine would

it depends on how true the center hole is to the rest of the turntable.I 
always use an indicator and pick up the center hole by revolving the
mill spindle and get a zero reading on all four quandrants.

							DENNIS